A Warm Winter Legacy: Leaf Flushing and Senescence Long-Term

Fall is in the air. Here in North Carolina that means drastic temperature swings that cause me to dress incorrectly on any given day. It also means the arrival of fall colors. Indeed, fall colors are incredibly beautiful, but biologically speaking, you are watching death happen. This autumn splendor got me to thinking about these colors a little closer, specifically the phenology of trees.

Phenology is the study of the annual timing of recurring life cycle events. The timing of these events is typically influenced by seasonal environmental changes. In the case of trees, specifically hardwood forests, this is the leafing-out (flushing) and dropping-off (senescence) of leaves. But what actually triggers a plant to leaf-out? This can vary a bit by species or even individual, but there are a couple of general categories you can look to. The first is changes in air temperature, the chilling in the winter and warming in the spring. The other is photoperiod, or the day length, which often interacts with temperature, allowing plants to quickly respond to changing conditions.

Considering that these events are triggered by environmental changes, it is logical to assume that global climate change can force changes in the phenology of many species and communities. This is another think-about-the-plants moment. How plants respond to climate change has huge consequences for world ecosystems – growing seasons, species ranges, carbon and water cycling, interactions with animals, etc.

A paper published earlier this year in PNAS took a look at variations in leaf flushing and senescence dates in relation to warming. Many phonological studies focus on specific phenophases (like leaf-out in the spring), but this study is unique in that it looks at subsequent phenological events. The authors aimed to see if effects of warming lasted longer than the current growing season. To do this, in December 2009 they took seventy 3-4 year old cloned oak and beech trees and put them in growth chambers where they could very carefully control the winter environmental conditions. They manipulated the temperatures of the growth chambers to create treatment groups of winter-spring warming, winter-only warming, and spring-only warming. Then, in spring of 2010 when the flushing was complete, they moved the trees out of the chambers and into a field. The trees stayed outside and were measured until the following spring of 2011. Leaf-out rates were determined using a scale that went from undeveloped bud to unfolded leaf, and leaf senescence was recorded as the date at which half of the leaves were colored or dropped. These measurements allowed for a quantification of growing season length. Additional measurements of numbers of leaf per tree, specific leaf area, total leaf area per tree, number of buds, dry weights of various parts of the trees, carbohydrate content, and carbon and nitrogen content were taken. They also combined their data with that of the European phenology network to get both a larger sample size and a wider geographic area.

The researchers found both leaf flushing and senescence in both species to be advanced 15-18 days by winter-spring warming. In the long-term, the timing of autumn leaf senescence was found to be positively correlated with spring leaf flushing dates, and advanced leaf flushing lead to earlier leaf flushing the following year. This suggests that the physiological impacts of a warmer winter last longer than just one growing season. Advanced leaf flushing in this winter-spring-warming treatment was also associated with some physiological and morphological changes, particularly in the oaks. These included higher leaf number, higher leaf area per tree, and higher starch accumulation.

The trends of the experiment were also observed in the mature trees in the long-term field-based phenology observations of the European phenology network. The underlying cause in both cases is likely that the plants never really fulfill the winter chilling requirements necessary for them to enter dormancy. Currently, the most widely accepted mechanism for leaf senescence is the environmental control hypothesis, which proposes that leaf senescence is triggered with the unfavorable autumn season comes (changes in photoperiod, temperature, or both). This study shows that perhaps that isn’t all that’s going on.

*sigh* nothing is ever simple is it?


Fu, Y., Campioli, M., Vitasse, Y., De Boeck, H., Van den Berge, J., AbdElgawad, H., Asard, H., Piao, S., Deckmyn, G., & Janssens, I. (2014). Variation in leaf flushing date influences autumnal senescence and next year's flushing date in two temperate tree species Proceedings of the National Academy of Sciences, 111 (20), 7355-7360 DOI: 10.1073/pnas.1321727111


For lots of really great info on the science of leaf-out, I recommend this review article:


Polgar, C., & Primack, R. (2011). Leaf-out phenology of temperate woody plants: from trees to ecosystems New Phytologist, 191 (4), 926-941 DOI: 10.1111/j.1469-8137.2011.03803.x



And you can contribute to leaf phenology research through Project Budburst!

Live Fast, Die Young: Evolutionary Outcomes of an Asteroid Impact

Figure 1: (A) "Dryophyllum" subfalcatum, (B) unknown nonmonocot,
(C) "Ficus" planicostata, (D) "Populus" nebrascensis

A new semester has started and with it an influx of new students into the lab has begun. Busy has become my middle name. So when I was looking around for a paper to write about I wanted something different and cool. Not exactly hard to find in science. The asteroid known as 2012 DA14 will narrowly miss Earth this Friday, the closest known asteroid flyby on record. And by close we’re talking within the orbits of many communications satellites. This got me thinking about and looking for recent papers about asteroids. It didn't take me long to come by an interesting new paper about the dino-killing Chicxulub bolide impact.

As of now, it is widely accepted that an epic asteroid collision ended the 135 million year reign of the dinosaurs. The Cretaceous-Paleogene boundary (KPB) extinction event is marked by the Chicxulub (CHEEK-sheh-loob) impact on the Yucatán Peninsula in Mexico. This asteroid or comet is estimated to have been about 6 miles (10 km), releasing as much energy as 100 trillion tons of TNT that caused a crater more can 110 miles (180 km) across! This impact coincides with a mass extinction event that includes the dinosaurs. Dramatic climate swings caused by the dust kicked up into the atmosphere were likely the culprit behind many of these extinctions. Before we go further, take a second to think about what you know about this extinction event. You probably think of the mass die-off of the dinosaurs and the subsequent rise of the mammals, right? But, as I have in the past, I’ll now pose a question: What about the plants?

A new paper published yesterday in PLOS Biology asks just that question. We know that in temperate North America the Chicxulub impact resulted in the extinction of over 50 percent of the plant species. From an evolutionary and ecological stand-point, that’s a lot of competitors that were taken out of the game. However, the environment was dramatically altered as well, changing to a cold and dark “impact winter.” Combined, these factors created a unique selection scenario for certain ecological strategies. The new paper takes a close look at the functional traits associated with these strategies.

The researchers measured fossil leaf assemblages spanning a 2.2 million year interval across the KPB, assessing four differing selection scenarios for functional traits. First, wrap your head around the concept of “functional traits.” These are characteristics that define species in terms of their ecological roles. In the case of leaves, these include leaf mass per area (LMA; Do you make a big, expensive leaf or a light, cheap one?) and leaf minor vein density (VD; Do you have more veins to transport lots of water?), among many others. Because leaves are the food producers, these traits are linked to plant growth and fitness. Next, you can relate these traits to the “leaf economic spectrum” (LES) that contrasts species with inexpensive short-lived leaves with fast returns on carbon and nutrients (deciduous, angiosperm, broadleaf) to costly long-lived leaves with slow returns (coniferous, gymnosperm, evergreen). The former is typically selected for in a less resource variable environment and vice versa. From this, you can get a more global perspective on changes in species composition.

The researchers measured LMA and VD for fossil leaf assemblages spanning the KPB. To do this they digitally photographed specimens that could be measured and confidently reconstructed. Then they used Photoshop to digitally separate the leaf from its rock matrix. For LMA they used ImageJ to calculate leaf area and petiole width, and then ran these numbers through empirical scaling functions (a.k.a. equations). For VD, they used a MATLAB line-counting program to isolate the veins and then manually counted the number of vein-line intersections, computing the mean distance between veins  as the sum of all line counts divided by the sum of all distances (a.k.a. a slightly less complicated equation). They ran a few scenarios to account for site and region plant specificity as well.

They found LMA to decrease and VD to increase across this time period. Even changes just these two traits reflect large physiological and biological shifts in plant functioning over a relatively short period of time. According to their data, the Chicxulub impact led to the selective extinction of species with slow strategies. This caused a directional selection away from evergreen species along with a stabilizing selection of deciduous angiosperms. The authors pose a few hypotheses in their discussion that are worth mentioning. The higher observed VD in angiosperms, and their ensuing selection, could have been driven by declining atmospheric carbon dioxide (CO2), which selects for higher hydraulic capacity. This CO2 hypothesis would, of course, not really hold water (no pun intended) for nonangiosperms and shade species, but the authors suggest that the observed increase in VD is more likely to be a direct consequence of the impact selecting for specific leaf economic strategies rather than ongoing-longer term climate change.

In this case, slow and steady did not win the race.


  Blonder B, Royer DL, Johnson KR, Miller I, & Enquist BJ (2014). Plant Ecological Strategies Shift Across the Cretaceous-Paleogene Boundary. PLoS biology, 12 (9) PMID: 25225914




(image via above citation)

Tips For Talking About Climate Change

Working in science automatically means you know everything about science. Duh. You're like one of those scientists we see on TV. So when you attend a large family gathering, Thanksgiving for example, you may be expected to explain a controversial topic. You know, since your the expert. The biggest one that people like to ask about, but have already have opinions on, is climate change. But there is a difference between talking at someone and having an effective conversation. An article over at the Environmental Defense Fund website gives you some tips to do just that, no matter who you run into. Their article is so well done that I'm just going to copy it as is, and a link to the original can be found at the bottom of the post.

"Climate change has become one of those divisive, polarizing issues that confound our political system. It's often hard to even have a civil conversation with folks who disagree, even with close relatives or friends.

 But it is clear that the climate crisis has arrived. And the key to solving it is educating those around us.

Chances are your friends and family fall into one of the following six categories:

• Alarmed Aunt Anna 
• Concerned Grandpa Christopher 
• Cautious Cousin Charlie 
• Disengaged Grandma Denise 
• Doubtful Brother David 
• Dismissive Aunt Debbie

The way people in each category respond to the climate issue varies. If you want to have an effective conversation, the way you talk about climate with different types of people should adjust accordingly.


Alarmed Aunt Anna & Concerned Grandpa Christopher


They believe the science is real, but may doubt our ability to solve the climate crisis.




Here are a few points that may inspire them to keep up the fight:

• California—the 8th largest economy in the world—has implemented the world's most ambitious climate action plan. 
• At the national level, the EPA is starting to regulate climate pollution using its existing authority under the Clean Air Act. 
• The renewable energy industry is growing exponentially—in fact, the clean energy economy is growing twice as fast as the rest of the economy, and we have enough potential wind and solar energy in the U.S. to power our economy 100 times over.

Trump Card: Yes, this is challenging. Yes, it will take time to rebuild support for national climate action. But what choice do we have? There is no time to waste, and we need to act now.

Cautious Cousin Charlie, Disengaged Grandma Denise and Doubtful Brother David 

These folks probably (and wrongly) believe that there isn't a true consensus on the science of climate change. We know that's not true, but don't go on the attack! They tend to be more open to changing their minds if they are engaged in effective conversation. 

Here are some basic facts that they'll find engaging:

• Carbon dioxide is a heat-trapping gas, and that's generally a very good thing. Without greenhouse gases, every night when the sun sets, temperatures would immediately plunge to frigid levels. 
• But, we are now emitting 9 billion tons of CO2 into the atmosphere every year, and CO2 levels have increased by about a third since the industrial revolution. If we don't reduce emissions, we could more than double the level of CO2 in the atmosphere over this century. 
• Already, food growing patterns are changing, seasons are coming earlier, water resources are strained and the number of natural disasters in the U.S. has more than quadrupled in the last 50 years.

Trump Card: You don't have to accept all the science. But, if you had a health condition and 98 out of 100 doctors agreed on the diagnosis, would you base your treatment on the views of the other two?

Dismissive Aunt Debbie

The truth is, there is almost no chance of changing her mind, and it's probably not worth trying unless you like banging your head against a wall. Ironically, research shows that the more facts you try to present, the less likely she will be to agree. However, even Dismissive Aunt Debbie will be open to arguments about stimulating the economy and protecting national security.



Try steering the conversation towards those issues:

• America needs to rebuild. Did you know the clean energy sector creates 3 times as many jobs as the fossil fuel sector? We can't afford to pass up those jobs. 
• Other countries are taking advantage of the economic stimulation that comes with climate action. China is testing carbon cap-and-trade markets in an area encompassing 250 million people. The U.S. needs to stay competitive. 
• America's billion-dollar-a-day dependence on oil from hostile nations directly funds our most dangerous enemies, putting guns and bullets into their hands and putting our soldiers in danger. It is time for America to stand strong on its own independent and in control of our energy future.

Trump Card: Whether climate change is real or not, the benefits of a clean energy economy are undeniable. Not only will we rid ourselves of dangerous pollution that can make us sick and even cause deaths we can finally be energy independent. What's the downside?"



Good luck!



The original can be found at EDF's page "Talking Turkey About Climate: Without starting a food fight"

All of the images found in this post are part of the original EDF article.

Dealing with Drought: How Do Plants Cope?

Have you noticed how often drought has been in the news lately? You don’t have to be a scientist to know that drought is bad. But, if you’re a plant, how bad is bad? I mean, you’re a plant; it isn't like you can pick up your roots and go looking for the nearest water source. You must have ways to cope, strategies that will let you survive until water arrives. A new paper in Tree Physiology caught my eye today that examines how plants handle drought in our changing climate.

We know that drought and elevated temperatures have all sorts of effects on ecosystems worldwide. The ecosystem level is a bit broad so let's narrow the scope a bit, just looking at plants. The average person tends to think about plants as just that: plants. They are green, they grow. Okay, but we really need to think of them as different species that have their own strengths, weaknesses, and strategies to cope with hard times. Different species of plants react to drought and elevated temperatures differently, some are better able to cope than others. It is known that drought and temperature influence seedling and sapling establishment and survivorship. To anthropomorphize a bit, some infant and toddler plants survive to grow up into adults and others...well...don't. The results of this survivorship will profoundly affect the composition of the community (collectively, which species are there) and how that community changes over time. Additionally, drought and elevated temperatures may affect our efforts to restore habitats. If newly planted saplings die within the first few years of planting then the restoration fails. If we get even more doom-and-gloom with it, extreme drought will cause massive forest dieback, releasing huge amounts of stored carbon and exacerbating the problem.

Let's narrow the scope a bit more. The survivorship of plants is related to their physiology and productivity. In general, growth is the most sensitive to drought. This is followed by photosynthesis and then respiration. The timing and extent of these declines is governed by changes and coping methods for water balance (water supply vs. water use), carbon balance, and strategies to balance the water loss and carbon gain. Most climate models predict that with increased atmospheric carbon dioxide (CO2) and warming the intensity and timing of droughts will go up. Now, carbon dioxide is good for plants because they use it like we use oxygen, to make energy. Give plants more CO2 and you see increased leaf area, productivity, photosynthesis, and carbon storage (in this case we are talking about non-structural carbohydrates (TNC)). Warming under well-watered conditions isn't too bad either, but under drought, warming will decrease photosynthesis and carbon storage while increasing water loss. But increasing CO2, warming, and drought are not solitary factors; you need to look at them in combination. Elevated CO2 will lessen drought stress, but warming worsens it. Based on what we know of the individual factors, the effects of elevated CO2 plus warming plus drought may vary depending on the trade-offs a plant makes. This new study in Tree Physiology looks at how drought alone and in combination with CO2 and warming affects carbon dynamics (growth, photosynthesis, respiration, TNC).

To do this they raised Blue Gum (Eucalyptus globulus) seedlings under ambient CO2 and temperature conditions. After one month they transplanted and separated them into their various treatment groups. These treatment groups were put in whole-tree growth chambers where the conditions could be very carefully controlled. There were four CO2 and temperature combinations: two CO2 levels (400 and 640 μl l−1) and two temperatures (28/17 and 32/21°C day/night, a.k.a.ambient and ambient + 3°C). Within each of these treatments, seedlings were designated to a drought regime: well-watered/control, sustained drought, rewatered drought (watering after sustained drought), and progressive drought (on rewatered and sustained treatments). They were able to maintain the "sustained drought" condition by adding just enough water to maintain leaf stomatal conduction (a measure of the rate of CO2 entering and water vapor exiting the stomata/pores of the leaf).

The researchers took gas exchange measurements, specifically looking at leaf net photosynthesis and leaf respiration rates. They also randomly selected individuals at various times during the experiment’s duration to be harvested for dry mass measurements (leaf, stems and roots). TNC concentration was calculated as the sum of starch and soluble sugar concentrations.

The results showed effects of progressive drought to be similar in rewatered and sustained drought plants. These plants were limited in growth, photosynthesis and respiration. However, there was not a decrease in TNC, although the drought plants did convert quite a bit of their starch into soluble sugar. This means that the plants consumed less TNC, and the soluble sugars likely serve some other function apart from a respiratory carbon source during drought (perhaps osmotic adjustment and/or hydraulic transport). They also found that elevated CO2 ameliorated the stress of their plants in the moderate drought treatments. These plants showed increased photosynthesis and TNC reserves. This suggests that the plants have the capacity to withstand drought, having sugar available for osmotic adjustment (think: better water movement, which is good for growth and photosynthesis). Conversely, elevated temperature exacerbated moderate drought stress by reducing photosynthesis, increasing leaf respiration and decreasing TNC reserves, and reducing the plants’ capacity to withstand drought. The combined effect of elevated CO2 and increased temperature is a little more complex. This study found only moderate benefits to plants, with similar/lower carbon uptake and greater carbon loss during the moderate drought treatment. TNC was found to be higher which suggests that there may be some carbon storage going on. However, these benefits went away when the plants were subjected to extreme drought. I suppose that is to be expected. They don’t call it extreme for nothin’ right?

Perhaps we can find a silver lining from this story. Plants are resilient organisms that have the capacity to withstand more than we had thought even when they are hit with multiple stressors. They can deal with moderate droughts, but extreme is still extreme and nothing survives everything. I didn’t say it would be a thick silver lining, but we can potentially use this knowledge to help us mitigate some of the effects of climate change and work to better restore lost habitats.


Duan, Honglang, Jeffrey S. Amthor, Remko A. Duursma, Anthony P. O’Grady, Brendan Choat, & David T. Tissue (2013). Carbon dynamics of eucalypt seedlings exposed to progressive drought in elevated [CO2] and elevated temperature Tree Physiology, 33 (8), 779-792 DOI: 10.1093/treephys/tpt061


(image via TrendsUpdates)

One Bottle at a Time

The Redwood Environmental Academy of Leadership (REAL) program started in 2007 with a Stanford K-12 Initiative grant. It focuses on teaching students academic and leadership skills through hands on service projects related to the environment. The students working with Jasper Ridge Biological Preserve's (JRBP) Tom McFadden and Halo Shapiro plus Stanford alum and editor Jake Wachtel created a rap video to highlight the global water crisis.

Getting to the Roots (and Fungi) of Carbon Sequestration

This week, I found a paper that I’m calling the best of both worlds. Well, for me at least. This paper combines my past (and lingering) interest in island biogeography with a current interest in climate change and carbon storage.

If you have been reading my blog long enough then you already know my love of islands. They are just so darn useful. In the past, I have focused on oceanic islands, but lake islands are also really neat. These types of islands typically form when lower lying land areas fill with water, effectively cutting off higher areas from the mainland and making them into islands. As such, these islands usually already contain forest as opposed to an oceanic island that emerges from the ocean and must be colonized. A new study, published in journal Science, looks at a fire-driven boreal forest chronosequence on forested lake islands in northern Sweden. Such a chronosequence allows the study of soil carbon sequestration over time scales of centuries to millennia.

This new study looks at roots and their associated fungi (mycorrhizae) as sources of this stored carbon. I’m not going to spend the space to describe mycorrhize, but will, instead, send you over to my Free Market Fungi post for more information, if you need it. It is known that 16 percent of the global carbon stock is sequestered in soils. To date, most carbon studies of this type focus on aboveground leaf litter as the fundamental determinants of this carbon accumulation. But a large portion of photosynthetically fixed carbon is actually directed belowground to the roots and, subsequently, the mycorrhizae. Now, let’s add fire. It has been shown that when a forest doesn't burn, the soil and ecosystem carbon accumulate unabated, and in a linear fashion. Add this information together and it becomes a big deal when it comes to correctly allocating carbon, calculating the long term sequestration rates, and predicting how forests will respond to climate change and other environmental shifts.

The study sites were in two adjacent lakes, Lake Hornavan and Lake Uddjaure, in northern Sweden. The islands in these lakes were formed after the most recent glaciation and come in a variety of sizes. In terms of fire, larger islands burn more frequently because they are larger targets for lightning strikes. As a result, several of the large islands in these lakes have burned in the last century, whereas some of the small islands haven’t burned in at least 5000 years. This lack of fire leads to very thick humus layers (or organic layers towards the top of the soil column) on smaller islands, up to 1 meter thick!

The researchers divided islands into three size classes of 10 islands each: large (over 1 ha), medium (0.1-1.0 ha), and small (less than 0.1 ha). They took soil samples from these islands to look at the organic soil profiles and found that large islands accumulated 6.2 kg of C per square meter belowground with a mean time since fire of 585 years, medium islands accumulated 11.2 kg of C per square meter with a mean time since fire of 2180 years, and small islands 22.5 kg of C per square meter with a mean time since fire of 3250 years. Then they looked at the carbon dynamics across this chronosequence by analyzing bomb 14C. This allowed them to determine the age since fixation of soil carbon. Then they fitted a mathematical model to measurements of carbon mass and age distribution across the soil profiles for six of the islands (3 large, 3 small). This model revealed that the distribution of carbon mass and age could only be predicted when they included carbon from roots. This root-derived carbon accumulation was found to be larger on small islands (70 percent, that's a LOT!) than large islands (47 percent). They were able to explain the entire carbon sequestration difference on small islands from these root-derived inputs. The model also showed that small islands store a major proportion of their soil carbon in the deeper soil layers, those over 100 years old. However, below 20 cm depth, the root-derived carbon inputs were shown to be low and to decompose slowly. So the root-derived carbon input into the upper layers probably contributes to the long-term buildup of humus that is seen on these islands. But, as usual, that's not the end of the story.

We know that fungi play very important roles in forest ecosystems, both as decomposers and in root-assoicated carbon transport and respiration. So the researchers also profiled the relative abundance of major groups of fungi by depth in the soil profiles. They found that the upper soil layers are dominated by free-living saprotrophs (fungi that obtain their nutrition heterotrophically from non-living organic materials), and greater depths were dominated by mycorrhizal and other root-associated fungi. Their model suggests that these mycorrhizae live at the spots where the largest difference in carbon sequestration between the island size classes exists, which also tends to be the areas of highest root mass. When they ran tests for fungal biomass throughout each soil profile they found greater mycelial (the vegetative part of a fungus, consisting of a mass of branching, threadlike hyphae) production on large islands, but less mycelial necromass (dead stuff) on small islands. This suggests that the large production is counterbalanced by faster decomposition of mycelial remains. “Correspondingly, the 14C model indicated faster decomposition of root-derived [carbon] on large islands, despite inputs being conservatively constrained to be equal across all islands.”

I found these conclusions to be interesting because of the amount of soil carbon from roots and mycorrhizal fungi, especially on small islands. And although they saw less carbon accumulation on large islands, these islands have a greater root density and so should have more carbon allocation to roots and the associated fungi. Did you catch the contradiction? Well, in response to increased carbon dioxide, there will be an increase of carbon inputs to the roots which will accelerate the turnover of soil organic matter. This counteracts carbon accumulation and enhances nitrogen cycling through the microbial pools, an effect these researchers observed when they tested the C:N-ratios in the humus of large islands. This is much lower on small islands, possibly because of impared mycorrhizal nitrogen mobilization and the accumulation of nitrogen in fungal remains. This leads to progressive nutrient limitations, then leads to changes plant productivity, leading to changes in community composition, which leads to changes in total belowground carbon allocation, that leads to changes in fungi.

Definately starting to grasp the importance of the belowground dirty stuff. There’s a whole lot of carbon down there that we need to start looking at, accounting for, and seeing where it goes. We know that changes in the environment such as climate change, soil fertilization, fire suppression, and forest management make big differences to the aboveground stuff. It only makes sense that the belowground stuff is impacted as well.


Clemmensen, K., Bahr, A., Ovaskainen, O., Dahlberg, A., Ekblad, A., Wallander, H., Stenlid, J., Finlay, R., Wardle, D., & Lindahl, B. (2013). Roots and Associated Fungi Drive Long-Term Carbon Sequestration in Boreal Forest Science, 339 (6127), 1615-1618 DOI: 10.1126/science.1231923

If you would like some follow-up reading I suggest:

Treseder, K. K. (2013-03-29) Fungal Carbon Sequestration. Science, 339(6127), 1528-1529. (DOI: 10.1126/science.1236338) 

Also check out the write-up in Nature "Fungi and roots store a surprisingly large share of the world's carbon"

(image via Forest Keepers)

How to Win a Climate Change Arguement

An interesting infographic. What do you think?

via Slate.com via Climate Desk

I'm a Climate Scientist

This gem is from the Aussies, specifically Hungry Beast.

The Silverback Playbook: Changing Climate and Ape Distribution

On occasion, I go back to my roots in biogeography and peruse that subset of journals for interesting articles. Admittedly, I now skip over some topics that I used to devour, such as the species-area relationship (the "most general, yet protean pattern" that has recently warranted a special virtual issue). These days, I tend to stop and read articles about distribution patterns, especially as they relate to current problems like climate change.

There are an increasing number of studies that show that climate change will affect species distribution patterns and biodiversity patterns in general. Temperatures, rainfall patterns, sea level changes, etc. are likely to cause geographic shifts in the ranges of plants and animals, altering their relationships with the environment and other species. The common methods for predicting these effects are called bioclimatic envelope models. Basically, these models try to determine the "climate envelope," a description of the climate that defines a species' range, and then map the geographic shift of that envelope under climate change. These types of models are useful for predicting distribution patterns, but they do not inform us about the underlying mechanisms that limit species' distribution and how species will change their behavior and/or the kinds of habitats where they can survive. Think about this behavior part a little more in depth, specifically taking brain size into account. It has been shown that large-brained species are better able to cope with seasonal changes in their environments, buffering themselves against modest levels of climate change, and are more resistant to extinction.

When you think of large-brained species, which ones come to mind? Probably the primates, specifically the African apes (gorillas and chimpanzees). What do we already know about these species? We know that they live in Africa (the most vulnerable of all continents to the effects of climate change), occur in similar habitats (although they differ somewhat in biogeographical ranges), are highly endangered, have highly restricted ranges, have a slow life history, have a large body mass, and have somewhat similar diets. Knowing this, how do you think climate change will affect them?

A study published in the Journal of Biogeography takes a look at how the behavior and distribution of African apes will be affected by climate change. They use a time budget model to investigate how climate warming and behavioral flexibility might affect ape survival. Time budget models are based on individual behavior, how much of an individual animal's time is spent on feeding, resting, traveling and socializing. An animal's time is limited (there is only so much time in a day) and so there is a constraint on the size of a group that can be maintained in a particular habitat which ultimately determines a species' distribution. These types of models can predict distribution as well as the bioclimatic envelope models, as they are based on simple climatological variables, with the added advantage of providing informing us about mechanisms of keeping a species in a particular habitat and evaluating the level of ecological stress in areas where it does occur. They applied this model to data from 20 natural populations of gorillas (Gorilla beringei and Gorilla gorilla) and chimpanzees (Pan troglodytes and Pan paniscus). The model looked at the relationship between climate, group size, body weight, and time budgets. They ran the model to predict ape distribution across Africa under a uniform worst-case climate change scenario, highlighting the importance of individual behavioral requirements for survival. I'm going to save you lengthy descriptions of the model parameters, time budget equations, and model testing. You can thank me later.

The study found that gorillas are more restricted by temperature variation than are chimpanzees. This may cause gorillas to suffer more strongly from the effects of global warming. Their larger body mass and smaller group sizes also increase their risk of extinction even with their behavioral flexibility. This doesn't mean that the chimps are unaffected. They found that chimpanzee communities will be significantly reduced even at locations where they are predicted to survive. The model showed that two critical factors may ultimately determine their survival at these locations: minimum viable community size and minimum party size. Although the distribution for both genera is in the downward direction, the two taxa are predicted to respond differently to changes in climate. Chimpanzees are expected to primarily suffer a reduction in community size because they will need to spend an increasing amount of their time moving and resting. And considering that minimum viable community size is one of the two critical factors, chimps will find it difficult to survive in any of their present habitats and may even go extinct. On the other hand, gorillas already live in small groups and when combined with a dramatic reduction in available habitat (again with the moving and resting time), climate change is predicted to have a stronger effect on their biogeography. However, the authors think that the few surviving populations should be able to maintain present-day group sizes, making them locally stable. Even if the changes in climate were not as extreme, the researchers think that their model would still predict that apes will suffer habitat loss simply due to time budgeting problems that may be reinforced by indirect effects (like temperature on leaf quality). Sure, behavioral flexibility may help, particularly with the more socially fluid chimpanzees, but the environment will support only what it can support (especially for hungry, large bodied creatures).

It is important to note that this study does not include anthropogenic (human caused) influences. Couple those with the doom-and-gloom predictions that the study already makes and it looks like it's bye-bye time for the big apes. That is a bit of a depressing note to leave the post on. Perhaps the good (or happy?) note to leave on is that studies such as these (that take mechanism into account) can give us better ways to predict and preserve optimal habitats, ultimately finding ways to best conserve these species. After all, that is the goal right?


Lehmann, J., Korstjens, A., & Dunbar, R. (2010). Apes in a changing world - the effects of global warming on the behaviour and distribution of African apes Journal of Biogeography, 37 (12), 2217-2231 DOI: 10.1111/j.1365-2699.2010.02373.x


(image via earthtimes.org)

The Rocky Mountain Parnassius Problem

Lately, I've been thinking about butterflies. I won't subject you to the interesting, if slightly convoluted, train of thought that led me to today's paper (this post is long enough as it is), but suffice it to say that we are back on the topic of butterflies and climate change. If you remember, back in March I wrote about a paper that explored how a single climate parameter can determine population dynamics in a butterfly species, the Mormon Fritillary (Speyeria mormonia) - An Early Spring Isn't Always a Good Thing. In that case, it was how snow melt time in the first year would affect butterfly fecundity through flower abundance.

Along these lines, a preprint in the journal Ecology takes a look at how regional climate, particularly winter and winter extremes, affects annual rates of population change. We know that climate change is causing range shifts in many species. Good examples of this can be seen in high elevation, typically mountainous regions. The idea here is that a warmer climate facilitates growth in areas where a colder climate had previously prevented growth. However, this warming trend is not the only prediction attached to climate change. Variability in climate and weather and the extremes of seasons and events are also expected to have a large impact on ecological processes. This means that not only do species have to respond to general climate warming but also to general and local extremes. Long-lived vertebrate species with overlapping generations may be buffered to this because such these extreme changes act primarily on a single age class or cohort. Short-lived, univoltine (one brood or generation per year) ectothermic species have little to no buffering, meaning the entire population is affected by these extreme events.

The authors of this study use long-term (15 year) estimates of population size for 21 subpopulations of the Rocky Mountain Apollo butterfly (Parnassius smintheus Doubleday) in Alberta, Canada. This species is common in the alpine meadows of the Rocky Mountains of North America. They are known to overwinter as pharate larvae inside the egg, hatching in May, feeding on their obligate host plant (Sedum lanceolatum), pupating in late June, emerging as adults in late July, and the females ovipositing on their host plant through August. Although they are common, they tend to occur in relatively small subpopulations, having limited dispersal, which makes them good for metapopulation studies and studies of local changes. The researchers estimated population size in each subpopulation using mark-recapture data. The climate variable they chose was the Pacific Decadal Oscillation (PDO) index, an index shown to have strong correlations with their chosen study site. This index “contrasts the spatial distribution of sea temperatures between the northeastern and northwestern Pacific Ocean after correction for mean global temperature…providing a single integrative measure of climate across western North America through its strong temporal correlation with both temperature and precipitation.” A positive PDO means that warm water is along the coast and are associated with warm, dry years inland. A negative PDO means that cooler water lies along the coast and are associated with cool, wet years. They used both annual PDO as well as seasonal PDO values corresponding to stages of the life-cycle that were of particular interest. Then they ran some models that I won’t go into (I’ve used up a lot of space and I haven’t even gotten to the results yet!).

These models showed that “more frequent climate extremes pose important consequences or animal population growth affected by climate.” They found that winter values of the PDO were a strong predictor of annual population growth. The effects of climate in these butterflies was found to be curvilinear wherein both extremes (too warm and too cold) result in population decline. This suggests that the variability and extremes predicted by climate change models will greatly affect the population dynamics of species such as this and that there may be less opportunity for them to adapt to general climate warming as the occurrences of these extremes increases. Additionally, the curvilinear nature of these results suggests some complications in the mechanisms involving range shifts. Their data support range shifts (either poleward or elevational) in that climate warming may sustain a positive population growth, although low latitude and low-elevation range margins might be affected more causing negative growth.

Are these results applicable to all species? No. P. smintheus is an alpine species that is naturally subjected to a cold, unpredictable environment, and, as such, they exhibit several behavioral, morphological and physiological adaptations. This means that curvilinear results of the model suggest multiple climate-related factors that need to be teased out (temperature, precipitation, snow cover, snow distribution, etc.) and that the PDO index itself may have a range with extreme values on its edges. Because these are extreme factors rather than just gradual shifts in climate, conservation planning could be more difficult over the long term. The extremes themselves decrease populations and the variability shrinks geographic ranges (depending on event and climate interactions) also causing decreases. Perhaps helping to curtail the effects of the short-term weather extremes may help in the long-term. As yet it is unknown, and, as with most science, needs more investigation.

I encourage you to read the entire paper. There are additional ideas and fleshing out of these conclusions that are particularly interesting.

Roland, J., & Matter, S. (2012). Variability in winter climate, and winter extremes, reduce population growth of an alpine butterfly Ecology DOI: 10.1890/12-0611.1


There are also a couple of articles that have nice interviews with the authors:
From EurekAlert! and the University of Alberta: "Climate change isolates Rocky Mountain butterflies"
ScienceDaily's article: "Climate Change Isolates Rocky Mountain Butterflies" 


(image via GeoLocation)

Dinosaur Farts: Climate Driver or Just Gas?

Hmmm, how do you begin a serious discussion about dinosaur farts? Maybe I should call it flatulence? How about methane emissions from sauropod posteriors? To be honest, it hasn't ever been something I've thought about before. A correspondence paper, published this month in Current Biology,on this topic caught my attention, and it caught the attention of several news outlets. Makes sense, I suppose. As one article put it, "It sounds like perfect journalist bait." Obviously perfect blogger bait as well. So I wanted to take a closer look at this paper and see what it's really talking about.

The paper, by researchers David Wilkinson, Euan Nisbet and Graeme Ruxton, concerns the methane produced by sauropod dinosaurs and if it helped to drive Mesozoic climate warmth. You'll remember our talk about sauropods from the Antarctic Sauraopod: No Longer a Cold Case post from January. These were often really really big creatures with a high level of diversity and large geographic range. It has even been suggested that they may have been a keystone species in many Jurassic and Cretaceous ecosystems.

But let's first start of with a modern comparison, probably one with which you are familiar: Livestock. Ruminant animals (cows, sheep, buffalo, and goats) have a unique digestive system that can convert otherwise unusable plant material into food. This digestive system, produces methane, a potent greenhouse gas that can affect climate directly through its interaction with long-wave infrared energy and indirectly through atmospheric oxidation reactions that produce carbon dioxide. A paper published in the Journal of Animal Science in 1995 estimates that ruminant livestock can produce 250-500 L (66-132 gallons [US, liquid]) of methane per day. The U.S. EPA estimates this to contribute about 80 million metric tons of methane annually. Ruminant livestock are one of the largest methane sources in the world. If you look specifically at cattle (as the J. Anim. Sci article does), they typically emit six percent of their ingested energy as methane. In the U.S. (which as about 100 million cattle) this accounts for about 5.5 million metric tons of methane per year. That's 20 percent of the country's methane emissions! I bring up this comparison because it is directly compared to sauropod emissions in this paper.

Now, dinosaurs, particularly sauropods, are a lot bigger than cows. But in terms of abundance, they were probably less numerous, with only a few tens of individuals per square kilometer. The digestive biology of these animals has, for a long time, stumped paleontologists. Sauropods have small teeth that are shaped for gripping and clipping plants, but not really for chewing or mashing those plants. How these plants were broken down is a bit of a mystery. There have been several hypotheses from small, swallowed stones called gastroliths to microorganism-assisted fermentation. The latter, as Wilkinson, Nisbet and Ruxton point out, could be the methane producing mechanism in these animals. However, it is unlikely that these dinosaurs had an endothermic, mammalian-style metabolism. And very unlikely that they were ruminant herbivores. So the authors did some calculations for these dinosaurs based on modern non-ruminant herbivores where methane (litres per day) = 0.18 (body mass in kg)^0.97. This means that for a 20,000 kg sauropod (about a medium sized Apatosaurus louise or "Brontosaurus"), the methane emission would be 2,675 liters per day from one animal. This scales up to 6.9 tonnes/km² of methane per year and a global methane production of 520 Tg (520 million tonnes) annually. Their estimation is similar to the amount of methane humans are currently pumping into the atmosphere each year rather than cows specifically.

OK. So what do we take away from this? Many news outlets have seized onto this and made pretty outrageous claims ("Dinosaurs may have farted themselves to extinction"....uhh, wow). The fact is that we don't know for sure.We don't know what the digestive systems of these animals was like. We don't even know if they produced methane at all. These estimates were derived from a modern animal model based on the methane output of rabbits and guinea pigs fed a hay-only diet. They might make me hand back my degrees if I called that a really great animal corollary. But, as one article put it, "If you know about croc fart research, please chime in." Then there is the issue of sauropod abundance. The estimations of population size were derived from the fossil record of the Morrison Formation, a 150 million year old sedimentary rock sequence in the western U.S. and Canada. Is this Formation an accurate slice of a prehistoric ecosystem? While we are on the topic of ecosystem, you should also consider the Mesozoic era which had slightly shorter days, more land area, and a warm, moist climate that supported greater primary productivity. How does this factor in?

Ultimately, the paper doesn't say that dinosaurs farted themselves to extinction. It doesn't mention dinosaur extinction at all. What it actually says is that "methane was probably important in Mesozoic greenhouse warming" and that their "calculations suggest that sauropod dinosaurs could potentially have played a significant role in influencing climate through their methane emissions." That's it. Dinosaurs may have farted. And big dinosaurs may have farted bigger.

Read the correspondence paper for yourself here:

Wilkinson, D., Nisbet, E., & Ruxton, G. (2012). Could methane produced by sauropod dinosaurs have helped drive Mesozoic climate warmth? Current Biology, 22 (9) DOI: 10.1016/j.cub.2012.03.042

More information about modern ruminant livestock emissions can be found at:
U.S. EPA site on ruminant livestock
Johnson, K.A. and D.E. Johnson (1995) Methane emissions from cattle. Journal of Animal Science: 73(8), 2483-2492.

And a couple of good articles about this paper:
Smithsonian's Dinosaur Tracking blog's post "Media Blows Hot Air About Dinosaur Flatulence"
Pharyngula's post "The reports of dinosaurs dying of farts are greatly exaggerated"

(image from the American Museum of Natural History)

Biodiversity Good, Extinction Bad, Climate Change Worse

This phylogenetic tree of life was created by David Hillis, Derreck Zwickil and Robin Gutell. It depicts the evolutionary relationships of about 3,000 species throughout the Tree of Life. Less than 1 percent of all the known species. Download the pdf from the Hillis Lab.

I hope we can all agree that: biodiversity = good, extinction = bad. This incredibly simplistic statement could be taken a number of ways, but, as we are doing with so many things lately, let's look at it through the lens of global climate change. How important is maintaining biodiversity? How bad is extinction? And how do these factors affect the function of ecosystems?

It has been established that the current rate of species extinction has far outpaced those rates we see in the fossil record. By "far outpaced," we're talking about a sixth mass extinction within 240 years (that's the projection as of now at least). There have been hundreds of experiments that have tackled this question of biodiversity and ecosystem processes, particularly in plant systems. Take a big statistical spoon and mix all the experiments together and you find that the loss of plant biodiversity affects biomass production and decomposition. Experiments to manipulate biodiversity in controlled environments have actually found that biodiversity can act as an independent variable that directly controls such ecosystem functions as nutrient cycling and biomass production. Studies have shown that greater biodiversity also increases these effects over time, likely by either a saturating response curve (large increases in ecosystem functioning as species are added to communities, leveling off after a while, with any additional species only increasing ecosystem functioning by small amounts) or a linear response curve (think: straight[er] line). These temporal aspects of diversity-productivity relationships are still somewhat obscure, particularly the mechanisms of these changes over time. Now add global climate change. It is uncertain the sizes these effects will be and how the direct effects of other types of environmental change (like atmospheric composition, nutrient pollution, etc.) will affect ecosystem functioning.

So far the month of May has yielded some big, interesting papers on the impacts of biodiversity loss. A paper by Peter Reich et al. in Science takes a look at the time component of biodiversity loss and how it affects the growth curves I mentioned above. In this paper, the authors present data from two long-running (≥13 years) grassland biodiversity experiments at the National Science Foundation's (NSF) Cedar Creek Long-Term Ecological Research (LTER) site in Minnesota, USA: the “Cedar Creek Biodiversity Experiment” (BioDIV), planted in 1994–1995, and the “Biodiversity, CO2, and N Experiment” (BioCON), planted in 1997. At these sites a number of plots are planted with different numbers of species of plants including various C3 and C4 plants and nitrogen (N)-fixing and non-fixing dicotyledonous herbs. The authors looked at the effects of diversity on biomass productivity and found that productivity (aboveground and belowground) increased and became less saturating over time; the diversity-productivity relationship became more linear and less strongly decelerating over time. Their evidence suggests that this may be due to the accumulating effects of complementary resource acquisitions and use and such ecosystem feedback effects as soil N cycling. Basically, the plants are complementing each other, increasing the functional diversity of the system. The greater the diversity of plants the more natural components (carbon, water, etc.) of the system can be capitalized on over time, a result that short-term experiments may underestimate.

The Cedar Creek LTER  site (Credit: David Tilman, UMN)

These ideas were discussed in a perspective paper by Bradley Cardinale, published in the same issue of Science. Here he points out that if Reich et al.'s conclusions prove to be general then they will have quantified how ecological impacts of extinction scale through time. Certainly not an insignificant conclusion. The Reich et al. paper doesn't spend a whole lot of time delving into niche theory (relational position of a species or population in an ecosystem, the where and how an organism makes its living), to the point that the word "niche" isn't even in their paper. But it is essentially what they are talking about, or at least hinting at.When species are accessing different resources then they are filling different niches, and the more diverse the species the more niches they can exploit. Cardinale knows quite a bit on this topic as he himself published a very nice study last year where he used a model system of stream biofilms, experimentally adding extra niche opportunities, to test the effects of algal biodiversity on water quality, showing that the more species in a stream the more ecosystem functions increased. Cardinale's examination of the Reich et al. paper points out some interesting points about the consequences these curves may have for conservation, specifically making the point that if the conclusions of the study hold true then biodiversity loss has probably already begun to degrade essential ecosystem processes.

Figure from Cardinale (2012)

Another paper published this month in Nature also takes a look at biodiversity loss as a driver of ecosystem change. In their study, David Hooper et al. use a series of meta-analyses of published data to look at the magnitude of the effects of species loss on productivity and decomposition. They focused on these two processes because they are major biological processes influencing carbon storage and other ecosystem services. Their analysis statistically summarized existing data, compared the environmental effect sizes to the estimated effects of species loss derived from a database of 192 peer-reviewed publications, summarized the results of 16 experiments that simultaneously manipulated plant species richness and some other environmental change variables (elevated CO₂, nutrient pollution, etc.), and assessed a large range of projections of species loss. This analysis showed that the biodiversity loss in the 21st century could rank as one of the major drivers of ecosystem change. In areas where local species loss is low (1-20%) there will be negligible effects. In areas of intermediate loss (21-40%), species loss is expected to decrease biomass production by 5-10 percent. In areas of high species loss (41-60%), the effects would rank alongside other major drivers such as warming, ozone, and acidification. They estimate that a 50% species loss will reduce biomass production by 13%. These reductions in biomass and decomposition don't sound like a lot, but, at least for decomposition, they are equal or greater than the effects of CO₂ or nitrogen. Hooper et al. also found that species loss would need to exceed that of prior mass extinctions (≥75% loss) to rival those environmental changes that have the greatest effect on primary production. Not a senerio that we will probably see globally, but locally or within certain taxa it could be realized if current extinction rates continue. Additionally, the types of species that are lost also have a huge effect. A good example of this was shown nicely in the Reich et al. paper above. When you add in other environmental changes to the meta-analysis it reinforces these conclusions.

I hope I've made my point that biodiversity = good, extinction = bad, and climate change = worse. I also hope I (and these authors) made the case that the loss of biodiversity isn't just a consequence but rather a major driver in key processes that affect our planet. Think about it.

You can read more in the articles:

Reich, P., Tilman, D., Isbell, F., Mueller, K., Hobbie, S., Flynn, D., & Eisenhauer, N. (2012). Impacts of Biodiversity Loss Escalate Through Time as Redundancy Fades Science, 336 (6081), 589-592 DOI: 10.1126/science.1217909

Cardinale, B. (2012). Impacts of Biodiversity Loss Science, 336 (6081), 552-553 DOI: 10.1126/science.1222102

Hooper, D., Adair, E., Cardinale, B., Byrnes, J., Hungate, B., Matulich, K., Gonzalez, A., Duffy, J., Gamfeldt, L., & O’Connor, M. (2012). A global synthesis reveals biodiversity loss as a major driver of ecosystem change Nature DOI: 10.1038/nature11118

Cardinale, B. (2011). Biodiversity improves water quality through niche partitioning Nature, 472 (7341), 86-89 DOI: 10.1038/nature09904

And here are some additional write-ups:
NSF story "Ecosystem Effects of Biodiversity Loss Rival Climate Change and Pollution"
NSF story "Plant Diversity Is Key to Maintaining Productive Vegetation" also at Science Daily

And some related websites you may want to visit:
Cedar Creak LTER site
LTER Network

An Early Spring Isn't Always a Good Thing

It is pretty well agreed upon within the scientific community that climate change is happening. It has become increasingly urgent that we nail down all of the individual facets of this very large change and the operation of environmental drivers. One of these is the operation of weather as a driver for population dynamics.

It is important at this stage to define weather versus climate. Weather is the state of the atmosphere at a particular time and place such as heat, cloudiness, dryness, sunshine, wind, rain, etc. Climate is the weather conditions prevailing in a place over a long period of time. So when we talk about weather, it is as a single climate driver that may have detectable effects on populations of organisms. These effects can be direct density-independent, have indirect effects on populations (act of food sources, predators, etc.), or act of population dynamics (age structure, life stages, etc.).

A new study, published in Ecology Letters, takes a look at how a single climate parameter can determine population dynamics in a butterfly species. The focal butterfly species they chose to work with was the Mormon Fritillary (Speyeria mormonia) because it is a species that is distributed throughout the North American Rocky Mountains and has non-overlapping generations. The adults of this species feed on nectar (the preferred floral nectar host is Erigeron speciosus) and young males feed from mud, dung and carrion. The females will mate once and lay their eggs singly in some leaf litter located near a host plant.The larvae will over-winter as unfed first instars and will develop into adults in about 6 weeks. Previous studies have shown that the fecundity of adult females declines linearly with their food intake with their eggs deriving up to 80% of their carbon composition from the sugars taken up by the adults. The host plants are useful in that they can be counted for flour availability which can be a broad indicator of nectar (food) availability for these females. Then add in the weather component. Frosts occurring early in the growing season will kill developing flower buds, reducing the food availability in the system. Keeping this in mind, the researchers hypothesized that snow melt time in the first year would affect butterfly fecundity through flower abundance (a delayed density-dependent indirect effect). In the year following this they predicted that snow melt time would directly affect the developing larvae. Remember, the larvae overwinter and mortality could occur due to exposure (a density-independent direct effect).

To test this, the researchers set up study sites in the Rocky Mountains of Colorado. They determined the floral hosts preferences and distribution of the hosts plants of the butterflies. They counted the blooms every other day in teach of their plots every year from 1975 to 2009 (except 1990). They also caught butterflies, took their demographics (size, sex, etc.), numbered their wings, and observed their feeding behaviors. Finally they recorded the snow melt timing within their sites.

After all kinds of population growth analysis that I'm not going to go into (you're welcome), they found that the timing of the snow melt affects the population dynamics of these butterflies both directly and through the density-dependent indirect effects on flower availability. The early snow melt reduced the flower (and therefore the food) supply, adversely affecting the butterfly population growth rate. In the second, consecutive year, the combined effects explained more than four-fifths of the variation in the population growth rate. Just a single weather parameter (in this case snow melt) can have multiple effects on population growth. This study is among the first to demonstrate these indirect effects as well as documenting the multiple effects that a single weather parameter can have on population dynamics. These researchers were able to take long-term data and apply it to data models to understand both the effects on a single species as well as understanding species interactions in the context of climate change. These types of experiments and models can help to predict changes in populations in the future and even across populations and species.

Here's the paper:


Boggs, Carol L. and David W. Inouye. (2012) A single climate driver has direct and indirect effects on insect population dynamics. Ecology Letters: published online March 14, 2012 (DOI: 10.1111/j.1461-0248.2012.01766.x)

Science Daily article about this paper:  Early Spring Drives Butterfly Population Declines: 'Ahead-of-Time' Snowmelt Triggers Chains of Events in the Mormon Fritillary Butterfly

(image from http://www.wildutah.us/html/butterflies_moths/nymphalidae/h_btfly_fritillary_mormon.html)

Science vs. Skeptics

An interesting infographic. A concise layout of some of the arguments from global warming deniers/skeptics vs. the consensus from the science community. Science isn't exactly known for short explanations about things, to the point where concise often looks like brushing off the issue. But this gives you a nice starting point for looking in to the issue and learning about the actual data, as well as some good discussion points.

via

(via visual.ly)

Happy International Talk Like a Pirate Day!

Ahoy, ya bilge rats, it be that most famous day of the year, ITLAPD (International Talk Like a Pirate Day). So grab a buxom wench or a seaworthy lad to practice your Arrrr's and learn a lesson on our favorite day, ya salty sea-dog. Aye, let's first get ye warmed up with some pirate-slang lessons...



Some might ask, why post about pirate-talk on a science blog. A few reasons: (1) why not? (2) you can't deny that talking like a pirate is super-fun, (3) I just got back from the Caribbean and although this isn't the scientific paper I promised it is still applicable, and (4) although it isn't directly linked to the Church of the Flying Spaghetti Monster it does have some fun tie-ins.

ITLAPD started on June 6, 1995 when John Baur and Mark Summers were playing racquetball. During the game they started giving encouragement in pirate-slang. One thing led to another until they decided that there really needed to be a national new holiday, Talk Like a Pirate Day. Mark came up with September 19th, his ex-wife's birthday (I'm sure she was so flattered), and they decided that Dave Barry would be the perfect spokesman. Things stayed pretty quiet after that. Until 2002 when they chanced upon Dave Barry's email address and explained their idea to him. Dave responded affirmatively and "all hell broke loose." Since then ITLAPD has become an international phenomenon.

That explanation covers most of the points on my why-list except for the Church of the Flying Spaghetti Monster (FSM). Now I'm not going to go all into this topic because the subjects aren't directly linked, they simply share a common topic...pirates. The Church of FSM emerged when Bobby Henderson posted this open letter to the Kansas School Board after their decision to permit the teaching of intelligent design as an alternative to evolution in public school science classes (but perhaps that is a topic for another day). Essentially, the Church of FSM believes that an invisible and undetectable flying spaghetti monster created the universe. Pirates were the original Pastafarians and were peaceful explorers until Christian misinformation listed them as outcast criminals. This actually supports that the religion is totally legit because it is backed by hard science, as evidenced by the pirate vs. global temperature data. If you refer to the graph below you will clearly see that as the numbers of pirates have decreased the average global temperature has increased. And here we find the unintentional but fantastic link between ITLAPD and FSM. Perhaps if more of us adopted piratey ways then we could decrease or even reverse global temperature rise.

So practice up on the pirate-talk ye scurvy dawgs and help to fight global warming. Arrrr....

The Official Site for International Talk Like a Pirate Day

Talk Like a Pirate Day UK Headquaters

Church of the Flying Spaghetti Monster