Tag Archives: Functional

Even Better than Gold: The Value of Protected Areas

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A look into the Itaimbézinho canyon, Aparados da Serra National Park, Brazil

The implementation of protected areas (PAs) is considered the backbone strategy of efforts towards the conservation of biodiversity and natural resources. Currently, the global network of PAs covers approximately 18.8% of the planet (15.4% of terrestrial and inland water and 3.4% of marine and coastal areas, see Fig. 1), safeguarding millions of species and providing a series of important ecosystem services such as water regulation, carbon neutralization, food, climate change mitigation and adaptation, as well as cultural and aesthetic services. Although many countries have committed themselves to increment the coverage of PAs in the upcoming years through international agreements, such as the Convention on Biological Diversity (which aims to assure that by 2020, at least 17% of terrestrial and inland water and 10% of coastal and marine areas are covered by PAs), they never been so threatened as now! A current, and overlooked, practice known as protected area downgrading, downsizing, and degazettement (PADDD) has become widespread in many countries, threatening and dismantling PAs everywhere due to economic interests such as mining, new power plant projects, etc.  (for more information and a global map see here; Also, a while ago, I wrote a post about PADDD in Brazil here). Thus, estimating the economic relevance of PAs and bringing this information to political and socioeconomic discussions has become an urgent task.

Protected areas of the World. Extracted from: Juffe-Bignoli et. al. (2014).

Protected areas of the World. Extracted from: Juffe-Bignoli et. al. (2014).

In a pioneering study, Andrew Balmford and colleagues have attempted to estimate annual numbers associated with PA visitation and their local and global economic impact. They compiled data from more than 500 terrestrial PAs from 51 countries and built regional and global models to estimate, among other things, the number of visitors, direct expenditure by visitors (calculated from expenditures with fees, travel, accommodation, etc.), consumer surplus (defined as the difference between what visitors would be prepared to pay for a visit and what they actually spend) and the effect of some explanatory variables, such as PA size, remoteness and national income, that might affect visitation rates. Based on these explanatory variables they could predict visit rates for roughly 100,000 PAs.

Their results demonstrate that PAs receive approximately 8 billion visits/yr. Visitation rates are predicted to be higher in Europe, where PAs would receive a combined total of 3.8 billion visits/yr, and lower in Africa (69 million visit/yr). Associations with individual explanatory variables varied regionally in their effect, but as one might expect, national income is a common factor affecting visitation rates in every region. PAs generate approximately US $600 billion/yr in direct expenditure and US $250 billion/yr in consumer surplus. An older estimative shows that less than U$10 billion/yr is spent in protecting and managing PAs, so if this number still roughly valid, for each dollar spent in maintaining them, we would profit ~ U$60, which makes it a hell of a good deal! It is important to note that, although this study seems to be the most comprehensive representation of the global economic significance of tourism associated with PAs, the authors themselves recognize that this number is likely to be an underestimate, so the direct economic return of investing in PAs might be much higher than that!

Now, consider that the economic value of PAs is much, much, higher if we take into account the value of other ecosystem services. A recent study published by Costanza et al. 2014 shows that the global annual economic value of services provided by natural ecosystems is ~U$125 trillion. The same study shows that in less than 15 yrs, changes in land use has promoted an annual loss of U$4.3–20.2 trillion in ecosystem services. Although I could not find a global indicator of the economic participation of PAs as providers of ecosystem services, it seems an obvious conclusion that in a time where natural landscapes are being altered, destroyed and fragmented at very fast rates, PAs will have an even greater importance in protecting the natural and economic wealth of the planet.

So even under the economic development argument, one is left to wonder how governments, politicians and some other sectors of society can consider PAs a “waste of land” and endorse practices such as PADDD?! I don’t really have an answer to this question, but studies like Balmford et al. will surely help conservation biologists to make their discipline more effective and guide society to take batter informed decisions.

 

References

Costanza, R., et al. 2014. Changes in the global value of ecosystem services. Global Environmental Change 26: 152-158. DOI: 10.1016/j.gloenvcha.2014.04.002

Juffe-Bignoli, D., et. al. 2014. Protected Planet Report 2014. UNEP-WCMC. Available at <http://www.unep-wcmc.org/resources-and-data/protected-planet-report-2014>

Mascia, M. & Pailler, S. 2011. Protected area downgrading, downsizing, and degazettement (PADDD) and its conservation implications. Conservation Letters 4(1): 9–20. DOI: 10.1111/j.1755-263X.2010.00147.x

March 11, 2015

Best of Biodiversity in 2014

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By Tsirtalis (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Biodiversity success of 2014! The Island night lizard was delisted under the Endangered Species Act in 2014. Photo by Tsirtalis (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Happy New Year! To put the cap on 2014, we’ve highlighted some of our favorite biodiversity research and stories from the year. We’d love to hear what rocked your 2014 – pass us the link in the comments section!

Hundreds of new species have been described this year all over the world. Here are some of my favorites:

  • A fossilized skull of one of the largest mammals that walked along with the dinosaurs in the Late Cretaceous, was discovered in Madasgcar. The species named Vintana sertichi was a 9kg gondwanatherian herbivore, that reminds me of a coypu. Up to now, the only information we had about gondwanatherian mammals came from teeth and small pieces of jawbones;
  • A new species of annual fish from southern Brazil, Austrolebias bagual (bagual is a term from the Pampas that means untamed, unbroken horse or unsocial);
  • The mushroom looking animals, form the deep oceans of Australia, Dendrogramma.
  • A montane forest dwelling Tapaculo, form northeastern Brazil.
  • And the coolest one; a new species of tree frog from the Amazon has been named after the Prince of Darkness, Ozzy Osbourne.

At last, a couple of species  have been declared extinct in 2014 (for more information see the timeline of extinctions):

  •  Acalypha wilderi, a small shrub that inhabited the Cook Islands.The species has not been seen since 1929, and it seems that it disappeared due to habitat modification;
  • Stipax triangulifer. This is a “virtually unknown” arachnid species that was collected only once in 1894 in the Seychelles island of Mahe, and was never spotted again.

-Vinicius Bastazini

The Avian Phylogenomics Project, an international team with more than 200 researchers worked in a collective effort to sequence the whole genome of 45 bird species, comprising the main clades of modern birds. The project published 28 papers, in journals like Science, Gigascience and Genome Biology, in just one day! One of their key papers is Jarvis et al., “Whole -genome analysis resolve early branches in the tree of life of modern birds”. Among their main findings are: 1) Two events of speciation happened around 66 mya, just after the dinosaurs went extinct, giving origin to most of the birds we know nowadays; 2) Avian genome is very reduced, with few repetitive DNA; 3) Vocal learning evolved independently, at least twice; 4) Tooth loss happened from lost enamel mutations, around 116 mya. Nonetheless, the most important steps accomplished by the group, is a better representation of the phylogenetic relationship of birds, with some very impressive changes, e.g. falcons are closer relatives to parrots than to other group of prey birds like hawks. Several other fields of biology must benefit from this better solved piece in the puzzle of the tree of life, especially fields like ecology, which in the last years has investigated the phylogenetic structure of communities as a way to understand patterns of diversity on Earth and the processes determining them. Maybe two last very important messages from Jarvis et al. (and the other of papers resulting from this project) are that: 1) basic science (e.g. taxonomy) is an essential tool for the next big steps toward understanding life on Earth; and 2) improvements on scientific knowledge are more and more related to collective efforts of huge networks of scientist and institutions around the world, working together in ambitious projects.

– Jeferson Vizentin-Bugoni

Some of my favorites from 2014:

– Kylla Benes

orange lichen

Forget horses, 2014 has been the year of the lichen. And although most readers are probably uninclined to overthrow thousands of years of Chinese tradition to make it so, I’m here to tell you why it’s worth the effort. Ecologists studying lichens have worked hard this year to push their traditionally esoteric research subject out into mainstream ecology. In honor of 2014’s listicle-mania, here are the top four ways that lichenologists have really broken the mold. You won’t believe what they found…

4. Lichens impact ecosystems at both micro and macroscales. From Porada et al comes a brand-new estimation of how lichens contribute to global biogeochemical cycles. Zooming in, Delgado-Baquerizo et al show that lichen species in biological soil crusts can cause fine-scale variation in the nutrients and microbes that reside under them.

3. Lichens are great for testing general ecological theory and models, both new and old. Pastore et al found no evidence for a competition-colonization tradeoff in the life-history traits of lichens inhabiting rocks over a 30+ year experiment. Time to lay this old idea to rest? From Ruete et al comes a cool new model for estimating dispersal rates in a metapopulation that is at disequilibrium from presence/absence data, patch ages, and past distributions. Because really, when aren’t we in a disequillibrial state? And yes, they tested it with lichens because epiphytes are great models of meta-structure.

2. We have discovered that lichens have traits too! Farber et al found that the performance of lichens with light-absorbing versus light-reflecting pigments recapitulated the distribution of these species along a vertical light gradient in boreal tree canopies. Lichens, however, may be more variable in their traits than plants or animals. Asplund & Wardle found that the community-level response of lichen N and P-content to a nutrient gradient occurs mainly intra-specifically, and not because of species turnover. Perhaps fungi are more flexible?

1. It’s been a great year for lichens’ better half- the algae and cyanobacteria that do all the photosynthesizing in the relationship. Although historically underappreciated by lichenologists, this year saw a barrage of papers exploring diversity of these “photobionts”, from across whole communities and large taxonomic groups (Lindgren et al, Nyati et al, Sadowska-Des et al) to genetic diversity within a single lichen individual (Dal Grande et al). It’s becoming increasingly evident that partner specificity and local adaptation among photobionts is a key determinant of whether a lichen-forming fungal species has a broad (Werth & Sork, Muggia et al) or narrow distribution (Dal Grande et al). With increasing interest in the ecology of microbial systems, the role of symbiosis in the community ecology of lichens is ripe for research. If 2014 was the year of the lichen, 2015 will be for their algae.

– Jes Coyle

2014 by the numbers:

Hero Ant

This is what a hero looks like (Malagidris sofina)

221 – the number of new species described by CalAcademy of Sciences this year. I was particularly charmed by the description of the defensive behavior of the Hero Ant of Madagascar (Malagidris sofina), which hurls itself at invaders, kamikaze-style, knocking them off the nest. See for yourself.

2,218 – Number of plants and animals currently listed as threatened or endangered by the Endangered Species Act. There is an active recovery plan for about half of those.

1 – Number of species delisted under the ESA during 2014. The Island night lizard (Xantusia riversiana), the poster child of this post, was originally listed in 1977, and has benefitted from the removal of invasive mammals from the Channel Islands, and is considered recovered.

90% – Estimated population losses for the Monarch butterfly over the past two decades. They are now being considered for ESA listing.

1.6 million – Area (km²) proposed in 2014 as additions to marine protected areas worldwide, including Fiji, Gabon, Palau, and the US.

– Emily Grason

December 30, 2014

The Early Evolution of Biodiversity

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Untitled

A wise man once said “sometimes you’ve got to go back to actually move forward” (this man was later mocked by a wiser man, which is a subject for another post that I probably won’t get around to writing). After much reflection, I have discovered the true meaning of this purposefully and poetically vague declaration. The well-spoken chauffer was in fact referencing how understanding early eukaryotic evolution can help us interpret the biological processes and cellular mechanisms of modern eukaryotes, which in turn can give us a better appreciation for the origin and diversity of complex life. It’s an insightful message, but I’d expect nothing else from a company whose slogan is “Lincoln: our cars are fine and all but how about the intricacies of cellular biology?*”. Luckily for us, some members of the scientific community have taken this quote to heart by examining the origin of eukaryotic cells. One main objective for many of these studies is to explain how plants, animals, fungi, and other eukaryotes developed all those special bits and pieces (such as a nucleus, an endoplasmic reticulum, and mitochondria) that separate them from prokaryotes.

For many years the prevailing idea was called the endosymbiotic theory, which basically said that one cell engulfed another and boom, nucleus in cell. A key aspect of this theory is that the plasma membrane of the eukaryotic-precursor was the membrane of the original host cell, and the nucleus was derived from the engulfed bacteria. Thus, the outside of the eukaryotic cell as we know it didn’t change much, while the interior of the host cell experienced more drastic modifications. However, a new paper by David and Buzz Baum in BMC Biology proposes a different theory of early eukaryotic evolution. Coined the “inside-out” theory, it claims that the early host cell was in fact the precursor to the nucleus, and that the bacteria (which were the precursor to mitochondria) were slowly engulfed by protrusions extending from the host cell. These protrusions eventually grew large enough to surround the bacteria and the host cell, and eventually became closed off to the external environment, forming the plasma membrane found in modern eukaryotes. The authors suggest that natural selection may have favored larger protrusions, since they would have increased the surface area of the host cell, potentially making any symbiotic relationship with external bacteria more metabolically efficient.

Untitled

An illustration of Baum and Baum’s “inside-out” theory, taken with permission from their 2014 article “An inside-out origin for the eukaryotic cell” published in BMC Biology.

Ok, you may be saying, but tell me about these fabled mitochondria. Specifically, what were they before they became organelles? Well, a separate paper by Wang and Wu out of the University of Virginia attempts to recreate the ancient pre-mitochondria using primarily phylogenomic data. With this genetic information from mitochondria and their close relatives, the authors hypothesized the structure, metabolism, and ecology of these ancient bacteria. Their results suggest that these premitochondria were capable of more diverse cellular processes than their specialized descendants, including DNA translation, replication, and maintenance, membrane biogenesis, energy production, motility via flagella, and respiration at low oxygen levels. Interestingly, their data also predicted that premitochondria utilized a specific translocase protein that exchanges bacterial ADP with ATP from a host cell. The presence of this protein suggests that premitochondria were internal “energy parasites,” and did not develop a mutualistic relationship with their host until later on down the road. Therefore, the initial symbiotic relationship between the eukaryotic ancestor and premitochondria may not have been one of mutual benefit (gold-diggin bacteria amirite?).

There are still plenty of unanswered questions from these two articles. If the early relationship was not mutualisitic, then you would not expect the host cell’s protrusions to necessarily be a result of a gain in fitness. In fact, if premitochondria were parasitic, then increased surface area resulting in a greater number of bacterial symbionts would seem to be a trait to be selected against (unless the protrusions provided some other fitness benefit that outweighed the increase in parasites). But probably the most pressing question is how and why did premitochondria do a complete 180 and suddenly become generous with their energy production? Evolution isn’t a Charles Dickens Christmas novel. Instead, I’d like to see a study geared towards reconstructing the events that led up to such a drastic change in the relationship dynamics between the early eukaryotic cell and its premitochondria, and how exactly these bacteria became energy producing organelles. Regardless of what future studies may show, it appears that the origin of early complex life, and ultimately the evolution of much of Earth’s biodiversity, may be more enigmatic than previously thought.

*If anyone from Lincoln’s HR department is reading this, let me know where I should send my resume.

November 25, 2014

Why Conservation? Communicating Applied Biodiversity Science

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ABS_2color_web

Applied Biodiversity Science Program – Texas A&M University

You might have a favorite science writer. Mine are David Quammen, Bill Bryson, Carl Sagan, and Tim Flannery. Others may be more inclined to read Pulitzer Prize-winning and nominated authors like Jonathan Weiner, Siddhartha Mukherjee, or James Gleick, MacArthur-fellow Atul Gawande, or consummate greats like E. O. Wilson, Richard Dawkins, Stephen J. Gould, and Oliver Sacks. Or perhaps books aren’t all you’re interested in. In that case you may be a fan of Carl Zimmer’s blogging or the stories and editorials from journalists/authors Malcolm Gladwell or Stephen J. Dubner.

It’s likely you’ve read at least one of these authors. Like most readers you were probably impressed by how well they articulated the complexities and subtleties of their topic: everything from astrophysics to evolution, cancer, neurology, chaos theory, economics, and psychology. If you find an author who draws you into a topic that wouldn’t otherwise gain your attention, particularly an unfamiliar scientific discipline, take notice. Take stock of what they have accomplished by gaining your interest and curiosity. As George Gopen and Judith Swan stated in their 1990 for American Scientific, “the fundamental purpose of scientific discourse is not the mere presentation of information and thought, but rather its actual communication.” Good communication requires gaining the reader’s attention. Attention requires garnering interest and curiosity.

In our ever-connected world with vast communication and social networking ability, we have the ability to do just that. We possess the tools to communicate science to a diversity of people in a diversity of ways.

As a member of the Applied Biodiversity Science Program (ABS) at Texas A&M University I find myself in a position where communicating science is an imperative for success. The ABS program is graduate program originally funded by the National Science Foundation as part of their Integrative Graduate Education and Research Traineeship (IGERT) program. The principle mission of ABS at Texas A&M is to achieve integration between biodiversity research in the social and natural sciences with on-the-ground conservation practices and stakeholders.

To that end, a foundational component of ABS is to communicate across scientific disciplines with various institutional actors to facilitate broader impacts across the realm of conservation. In essence, the ABS Program seeks to produce applied scientists who can communicate effectively across disciplines. A natural corollary of this goal is the ability to communicate science outside the realm of science. In this respect, our ABS Perspectives Series is intended to communicate more broadly and inclusively who applied biodiversity conservationists are, what we study, where we conduct research, how we conduct research, and why we are doing it. The current issue of the ABS Perspectives Series, features experiences from the Caribbean, the United States, Sénégal, Ecuador, Nicaragua, and Costa Rica. Contributions cover topics ranging from captive parrot re-wilding with pirates to blogging in the Nicaraguan forest with limited Internet access.

Perhaps more importantly, the ABS Perspective Series wants to reach out and share ABS student and faculty experiences with a diverse readership to raise awareness of biodiversity conservation issues. Outreach is an important axiom of actionable science, especially outreach that informs, improves and influences management and policy. I consider both the ABS Perspectives Series and BioDiverse Perspectives outreach initiatives to communicate the biodiversity conservation mission to the general public, communities where our research has been conducted, fellow academics and practitioners, and institutions that can provide logistics, infrastructure, and support. We must intend to make and practice making our research accessible and intriguing to everyone.

November 18, 2014

The dark side of theoretical ecology

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Figure1

Figure 1. Three types of mathematical models of complex dynamic systems.

Dedicated to the memory of Sir John Maddox (1)

Good science must be transparent in its theories, models and experiments. In my own research I often remember David Tilman’s great article which draws attention to the fact that ecologists investigate interspecific competition phenomenologically, rather than mechanistically (2). The article was published in 1987, however it is relevant for biodiversity science and mathematical modeling of complex systems even today. It discusses a problem among field experiments designed to test for the existence of interspecific competition in natural communities. Tilman suggests, ‘The design of the experiments, though, is a memorial to the extent to which the often-criticized Lotka-Volterra competition equations still pervade ecological thought. The experiments used a nonmechanistic, Lotka-Volterra-based, phenomenological definition of competition: two species compete when an increase in the density of one species leads to a decrease in the density of the other, and vice versa. … With a few notable exceptions, most ecologists have studied competition by asking if an increase in the density of one species leads to a decrease in the density of another, without asking how this might occur. … Experiments that concentrate on the phenomenon of interspecific interactions, but ignore the underlying mechanisms, are difficult to interpret and thus are of limited usefulness.’(2) To design an adequate field experiment we should have a mechanistic model based on a mechanistic definition of interspecific competition. Otherwise, we will not be able to overcome the limitations of phenomenological approach which hides from us internal functional mechanisms of ecosystems. Only a mechanistic approach will allow us not only to constate the loss of biodiversity, but to understand what needs to be done to save it. How to create such a mechanistic model? First, we need to know how to mechanistically model a complex dynamic system. A complex dynamic system may be considered as consisting of subsystems that interact. Interactions between subsystems lead to the emergence of new properties, e.g. of a new pattern formation. Therefore we should define these subsystems and logically describe their interactions in order to create and investigate a mechanistic model. If we want to understand how a complex dynamic system works, we must understand cause-effect relations and part-whole relations in this system. The causes should be sufficient to understand their effects and the parts should be sufficient to understand the whole. There are three types of possible models for complex dynamic systems: black-, grey-, and white-box models (Figure 1).

Figure1

Black-box models are completely nonmechanistic. We cannot investigate interactions of subsystems of such a non-transparent model. A white-box model of complex dynamic systems has ‘transparent walls’ and directly shows underlying mechanisms – all events at micro-, meso- and macro-levels of a modeled dynamic system are directly visible at all stages. Logical deterministic cellular automata is the only known approach, which allows to create white-box models of complex dynamic systems (3). A micro-level is modeled by a lattice site (cellular automata cell). A meso-level of local interactions of micro-objects is modeled by a cellular automata neighbourhood. A macro-level is modeled by the entire cellular automata lattice. Unfortunately, this simple approach is commonly used in the overloaded form, what makes it less transparent. This is achieved by adding differential equations and stochasticity. Grey-box models are intermediate and combine black-box and white-box approaches. Basic ecological models are of black-box type, e.g. Malthusian, Verhulst, Lotka-Volterra models. These models are not individual-based and cannot show features of local interactions of individuals of competing species. That is why they principally cannot provide a mechanistic insight into interspecific competition.

A white-box model of a complex system is completely mechanistic. A white-box modelling is axiomatic modelling. To begin to create a white-box model we need to formulate an intrinsic axiomatic system based on a general physical understanding of the subject area under study. Axioms are first principles of the subject. René Descartes proposed that axiomatic inference is universal for any science on condition that a system of axioms is complete and provided that axioms are unquestionably true, clear and distinct (4). Descartes was inspired by Euclidean geometry which investigates the relations between ideal spatial figures. When scientists verify a theory first of all they should strictly verify its axioms. If at least one axiom is inadequate or an axiomatic system is incomplete, then the theory is inadequate too (5). Let’s consider an example of the inadequacy of ecological models in result of incompleteness of their axiomatic system. There are many models of population dynamics that do not take into account what happens with individuals after their death. Dead individuals instantly disappear with roots, stubs, etc. ‘One reason for the lack of understanding on the part of most botanists results from their failure to take into account the phenomenon of regeneration in plant communities, which was first discussed in general terms by A. S. Watt in 1947.’ (6)

Stephen Hubbell in his Unified Neutral Theory of Biodiversity (UNTB) in fact refuses a mechanistic understanding of interspecific competition: ‘We no longer need better theories of species coexistence; we need better theories for species presence-absence, relative abundance and persistence times in communities that can be confronted with real data. In short, it is long past time for us to get over our myopic preoccupation with coexistence’ (7). However, he admits that ‘the real world is not neutral’ (8). Since the basic postulate (axiom) of the UNTB about ecological neutrality of similar species is wrong, this theory cannot be true. In addition, local interactions of individuals are absent in the neutral models in principle. That is why neutral models cannot provide a mechanistic insight into biodiversity. The UNTB models are of black-box and dark grey-box types only – Fig.1. I agree with James Clark, that the dramatic shift in ecological research to focus on neutrality distracts environmentalists from the study of real biodiversity mechanisms and threats (9). Within the last decade, the neutral theory has become a dominant part of biodiversity science, emerging as one of the concepts most often tested with field data and evaluated with models (9). Neutralists are focused on considering unclear points of the neutral theory – the ecological drift, the link between pattern and process, relations of simplicity and complexity in modelling, the role of stochasticity and others, but not the real biodiversity problems themselves (8). Attempts to understand neutrality instead of biodiversity understanding look like attempts to explain the obscure by the more obscure. Nonmechanistic models make it difficult to answer basic ecological questions, e.g. Why are there so many closely allied species? (10) An example of the difficult ecological discussion is the debates ‘Ecological neutral theory: useful model or statement of ignorance?’ on the forum Cell Press Discussions (11).

Understanding of mechanisms of interspecific coexistence is a global research priority. These mechanisms can allow us to efficiently operate in the field of biodiversity conservation. Obviously, such knowledge must be based on mechanistic models of species coexistence. In order to create a practically useful theory of biodiversity, it is necessary to renew attempts to create a basic mechanistic model of species coexistence. But the question arises: Why do ecological modelers prefer to use the heaviest black-box mathematical methods, which cannot produce mechanistic models of complex dynamic systems in principle, and not use simple and long-known pure logical deterministic cellular automata, which easily can produce white-box models and directly obtain clear mechanistic insights into dynamics of complex systems?

 

Acknowledgements

I thank Vyacheslav L. Kalmykov for useful discussions and suggestions.

I thank Kylla M. Benes for helpful suggestions and edits.

 

References

1.              J. Maddox, The dark side of molecular biology. Nature 363, 13 (1993). doi: http://dx.doi.org/10.1038/363013a0

2.              D. Tilman, The importance of the mechanisms of interspecific competition. The American Naturalist 129, 769 (1987). doi: http://dx.doi.org/10.1086/284672

3.              L. V. Kalmykov, V. L. Kalmykov, Verification and reformulation of the competitive exclusion principle. Chaos, Solitons & Fractals 56, 124 (2013). doi: http://dx.doi.org/10.1016/j.chaos.2013.07.006

4.              R. Descartes, Discourse on the method of rightly conducting one’s reason and of seeking truth in the sciences. D. A. Cress, Ed.,  (Hackett Pub. Co., Indianapolis, 1637/1980), pp. xiii, 42 p.

5.              B. Spinoza, Principles of Cartesian Philosophy: And, Metaphysical Thoughts.  (Hackett Pub. Co., 1998).

6.              P. J. Grubb, The maintenance of species-richness in plant communities: the importance of the regeneration niche. Biological Reviews 52, 107 (1977). doi: http://dx.doi.org/10.1111/j.1469-185X.1977.tb01347.x

7.              S. P. Hubbell, The unified neutral theory of biodiversity and biogeography. Monographs in population biology ; 32 (Princeton University Press, Princeton, N.J. ; Oxford, 2001), pp. xiv, 375 p.

8.              J. Rosindell, S. P. Hubbell, F. He, L. J. Harmon, R. S. Etienne, The case for ecological neutral theory. Trends in Ecology & Evolution 27, 203 (2012). doi: http://dx.doi.org/10.1016/j.tree.2012.01.004

9.              J. S. Clark, Beyond neutral science. Trends in Ecology & Evolution 24, 8 (Jan, 2009). doi: http://dx.doi.org/10.1016/j.tree.2008.09.004

10.           Anonymous. British Ecological Society: Easter Meeting 1944: Symposium on “The Ecology of Closely Allied Species”. Journal of Animal Ecology 13, 176 (1944). Stable URL: http://www.jstor.org/stable/1450

11.           P. Craze, Ecological neutral theory: useful model or statement of ignorance? Available from Cell Press Discussions: < http://news.cell.com/discussions/trends-in-ecology-and-evolution/ecological-neutral-theory-useful-model-or-statement-of-ignorance > (2012).

October 7, 2014

FLUMP – Ancient ecologial networks, climatic niche evolution, functional diversity

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A Lion and an Antelope Play a Board Game in an ancient Egyptian papyrus (c.1100 BC)

It’s Friday and that means that it’s time for our Friday link dump, where we highlight some recent papers (and other stuff) that we found interesting but didn’t have the time to write an entire post about. If you think there’s something we missed, or have something to say, please share in the comments section!

The latest issue of the PNAS features a very interesting study, led by Justin Yeakel, “Collapse of an ecological network in Ancient Egypt”. The Authors studied the ecological effects of the extinction of mammalian species in  Egypt, taking a very creative and remarkable approach in order to gather the data; they used artistic records found in tombs and in decorative objects produced over the past 6,000 years by the Egyptians in order to infer species extinctions and ecological dynamics. Their findings suggest that mammalian extinctions were non random and that large changes in the organization of these ecological systems coincide with periods of extreme drought and with the densification of the Egyptian population. Moreover, the decrease of diversity has led to an increase in the fragility of these ecological systems due to the loss of functional redundancy.

Adam M. Lawson and Jason T. Weir tested  whether the rate of climatic-niche evolution  of bird species varies with latitude, in a new preprint in Ecology Letters titled “Latitudinal gradients in climatic-niche evolution accelerate trait evolution at high latitudes“. The authors found a positive relationship between  latitude and the rates of climatic-niche evolution and that climatic differentiation is often associated with divergence in traits indicative of ecological differentiation and reproductive isolation.

 At last, I am happy to announce a new article, I co-authored with Jon Lefcheck and John Griffin, titled “Choosing and using multiple traits in functional diversity research”. In this commentary, we provide a brief discussion on choosing and using functional traits and some recommendations for best practice. We also explored, superficially, the behavior of some of the most used functional diversity indices, in terms of trait correlation, number of traits and species richness. If you are interested, check out the appendices to see the complete result of our simulation study and the R code for implementing it.

– Vinicius Bastazini.

September 11, 2014