Thursday, November 26, 2009

Understanding wildlife-friendly ecolabels

These days, it seems like nearly everything in the supermarket is good for the environment in one way or another. Over the past decade, more and more companies have started using ecolabels to collect a premium on products that claim to contribute to environmental protection.

But not all ecolabels are created equal. The credibility of their claims varies widely, ranging from environmentally meaningful to downright exploitative.

A recent study by Adrian Treves and Stephanie Jones provides a model for policy-makers and consumers to discriminate between claims.

“In a nutshell, [we] were looking for a way to analyze this cloud of ecolabels out there, all of them claiming to be the best thing for a given species or the best thing for a given ecosystem,” said Treves in an interview.

In the early stages of their research, Treves and Jones realized that wildlife friendly ecolabels can be split along the same lines that have divided debating groups of conservationists. They drew upon these divergent perspectives to partition wildlife friendly ecolabels into three categories.

“Supportive” ecolabels such as Endangered Species Chocolate donate some percentage of revenues to conservation organizations. Verifying the claims for this category is compromised by the transfer of funds to a third-party recipient who is usually not accountable to consumers.

“Persuasive” ecolabels claim to improve production methods in a way that eliminates threats to wildlife, but do not assess actual conservation of wildlife. Although the persuasive category is more transparent and environmentally effective than the supportive one, this type of ecolabel bases its certification requirements on assumptions about threats to wildlife without testing how reduction of perceived threats impacts wildlife. Tuna labeled as Dolphin Safe is an example of a persuasive ecolabel.

“Protective” ecolabels certify wildlife conservation by assessing whether reduction of threats enhances wildlife populations. The Marine Stewardship Council certifies fisheries under a protective ecolabel. This category is the most meaningful to wildlife because it matches the recommendations of the latest conservation science. By following the scientific method, protective ecolabels can verify that they actually help humans and wildlife coexist.

Just as conservation is often pitted against economic interests like agriculture or development, ecolabels must balance a trade-off between consumer confidence and producer incentive.

Protective ecolabels gain the most consumer credibility but also require the greatest verification effort. Proving that producers conserved wildlife is costly, time-consuming, and logistically challenging. Wild animals habitually ignore property boundaries and can die or disperse for reasons unrelated to producer activities. Often, the costs associated with these challenges outweigh the economic incentive of being labeled as “green.”

Treves, A. and S. M. Jones. 2009. Strategic trade-offs for wildlife-friendly eco-labels. Frontiers in Ecology and the Environment. DOI:10.1890/080173

(Image courtesy of kateboydell at flickr under a Creative Commons license)

Wednesday, November 25, 2009

Taking below-ground processes seriously: plant coexistence and soil depth

ResearchBlogging.orgSome of the earliest ecologists, like Eugen Warming and Christen Raunkiaer, were enthralled with the minutia of the differences in plant life forms and how these differences determined where plants lived. They realized that differences in plant growth forms corresponded to how different plants made their way in the world. Since this early era, understanding the mechanisms of plant competition is one of the most widely-studied aspects of ecology. This is such an important aspect of ecology because understanding plant coexistence allows us to understand what controls productivity in the basal trophic level for most terrestrial food webs. There are a plethora of plausible mechanisms for how plants are able to coexist, and most involve above-ground partitioning strategies (such as different leaf shapes) or phenological differences (such as germination or bolting timing). Yet, below-ground interactions among plants as a way to understand competition and coexistence have been making a strong resurgence in the literature lately. This resurgence has been driven by new hypotheses and technologies.In what is probably the best hypothesis test of the role for below-ground niche partitioning, Mathew Dornbush and Brian Wilsey reveal how soil depth can affect coexistence. They seeded 36 tallgrass prairie species into plot that were either shallow, medium or deep soiled, and asked if species richness and diversity were affected after 3 years. They found that species richness significantly increased with increased soil depth, revealing that deeper soils likely had greater niche opportunities for species. Not only did deeper soils harbor greater richness, but compositions were non-random subsets. The species inhabiting shallow soils were a subset of medium soils, and medium a subset of deep. This means that increasing depth opened new niche opportunities, unique from the ones for shallow soils.

This study is the first field-based experiment of soil depth and coexistence, that I know of and the results are compelling. Plant species are segregating below-ground niches, and perhaps we look for other partitioning strategies for species that inhabit the same soil depth.

Dornbush, M., & Wilsey, B. (2009). Experimental manipulation of soil depth alters species richness and co-occurrence in restored tallgrass prairie Journal of Ecology DOI: 10.1111/j.1365-2745.2009.01605.x

Other notable recent papers on below-ground processes:

Bartelheimer, M., Gowing, D., & Silvertown, J. (2009). Explaining hydrological niches: the decisive role of below-ground competition in two closely related species Journal of Ecology DOI: 10.1111/j.1365-2745.2009.01598.x

Cramer, M., van Cauter, A., & Bond, W. (2009). Growth of N-fixing African savanna species is constrained by below-ground competition with grass Journal of Ecology DOI: 10.1111/j.1365-2745.2009.01594.x

Meier, C., Keyserling, K., & Bowman, W. (2009). Fine root inputs to soil reduce growth of a neighbouring plant via distinct mechanisms dependent on root carbon chemistry Journal of Ecology, 97 (5), 941-949 DOI: 10.1111/j.1365-2745.2009.01537.x

Beware of the fake conference

I don't know about other researchers, but I get inundated with e-mails about upcoming conferences from organizations I've never heard of, on topics that, at best, only tangentially relate to my work. I think that most of these are put on by for-profit groups that try to cash in on hot topics. But now there are truly fake conferences that are fronts designed to get your financial information. In a new post by Bob Grant on The Scientist news blog, he relays a detailed example of such a scam conference. He went so far as to contact the venues and speakers listed by the scammers, and of course none of those listed had ever heard of the conference. The ultimate enticement was the offer to pay for travel expenses, and the presumption is that they would offer to reimburse you, but need your bank account information. The evolvability of internet scammers is truly impressive.

Sunday, November 22, 2009

Something fishy

Of the many victories wrought by DNA barcoding - the ability to place an unknown sample in a phylogenetic, and often taxonomic, context using short fragments of DNA sequence data - some of the most useful applications for management have come from the sea. One of the best citation-to-data ratios in this regard belongs to a 2004 study by Peter Marko. This project extended naturally from Marko's molecular ecology course: students purchased samples of "red snapper" from various fish markets, and sequence data from the mitochondrial cytochrome b gene region showed that most of these specimens were not, in fact, Lutjanus campechinus - they were often understudied and probably rare relatives, or in some cases not snapper at all. The conservation implications from this study were huge, and a number of papers have followed suit, looking at a variety of similar systems. If you aren't interested in adding to your list of papers to read, check out the short film based on work done in Steve Palumbi's lab that documents their work to identify shark fins.

In a paper by Lowenstein et al., published last week in PLoS ONE, the focus was on sushi, specifically tuna. The common labeling errors were caught again: there were mismatches between what restaurants called the fish, and what was actually being offered. In some cases, very phylo-distant species are being sold as "tuna", and these species can actually make consumers ill. The story is an interesting one of how fraud develops in samples of organisms that can no longer be visually tied to the species they came from, and the difficulties in protecting consumers from fraud under current regulations. Obviously, the perils of overfishing are becoming quite clear and interested readers should carry their Monterey Bay Aquarium seafood guides or similar (there's even an iPhone app for that!) with them before ordering at restaurants.

A particularly interesting advance in this study was taking the barcoding approach beyond the visual appeal of tree-building and similarity with databased sequence data. One concern about barcoding has been that even when a new clade appears in a phylogeny, taxonomy cannot be updated without some sort of diagnostic characters. It is uncommon for new species (especially of animals) to be described based on DNA sequence data alone, but it is nevertheless the norm to define the character states that uniquely define a species from its relatives. In Lowenstein et al.'s paper, they identified 14 diagnostic DNA substitutions that could be used to uniquely identify all species of Thunnus and suggested that focusing on particular characters within the "barcode gene" (mitochondrial cytochrome oxidase I) will also be necessary for new technologies to accelerate in-the-field identification.

This latter step is of interest for anybody interested in cryptic species, or identifications when other reference material is not available. I hassled one of my former Ph.D. students endlessly as she revised her dissertation because we had been comfortably using a phylogenetic tree to assign unknown individuals to one of three cryptic taxa (in the isopod genus Idotea), but prior to publication we knew that diagnostic characters would be necessary for subsequent work to be readily comparable. And, since the undergraduate evolution lab at the University of Georgia repeats Marko's work on red snapper every few years (the local Kroger now knows not to advertise their special on "red snapper from Indonesia"), perhaps the lab can be extended by having the students generate these characters for the genus Lutjanus as well. I don't seem to have any problem convincing students to do their homework when it involves going out for sushi.

Friday, November 20, 2009

Ross Crozier, evolutionary biologist and conservation biologist

Sadly, one of Australia's leading evolutionary biologists, Ross Crozier passed away suddenly last week (Nov. 12th, 2009). As a Professor at James Cook University, he worked on a plethora of evolutionary issues, from understanding the evolution of sociality in insects to population genetics and molecular phylogenetics. To my mind, his most influential papers were on how we can use patterns of evolutionary history in guiding conservation decisions -the agony of choice. While he promoted the conservation of phylogenetic diversity, per se, his great insight was that even comparing species that are relatively divergent does not mean that they are equally valuable, and we should consider information content as well. That is, a species with 80,000 genes is more valuable than a species with 20,000 genes, since the 80K-gene species has greater information content.

"Differences in the information content of genomes led to the realization that, other things being equal, some organisms have intrinsically higher conservation worth than others." -Ross Crozier

Ross also recently was the handling editor, at Ecology Letters, on a paper of mine and his insights and support were greatly appreciated and helped to improve our manuscript in numerous ways.

Here are my two favorite papers of his.

Crozier, R. H. 1992. GENETIC DIVERSITY AND THE AGONY OF CHOICE. Biological Conservation 61:11-15.

Crozier, R. H. 1997. Preserving the information content of species: Genetic diversity, phylogeny, and conservation worth. Annual Review of Ecology and Systematics 28:243-268.

Thursday, November 19, 2009

Eutrophication and fish depletion add up

The Baltic Sea is the world’s biggest brackish water body. The main threats for this unique ecosystem are eutrophication and overfishing. In coastal ecosystems eutrophication is considered to be the main factor causing the observed regime shift from long living canopy forming macroalgae towards systems dominated by ephemeral filamentous algae. Canopy forming macroalgae build nursery habitat, store nutrients, decline turbidity, and enrich water with oxygen whereas ephemeral algae can build large scale floating mats causing hypoxia and increase turbidity. Loss of top predators is known to cause trophic cascades. In the simplest scenario top predator loss means an increase in mesopredators, a decrease in grazers and thus an increase in algae growth. There is growing evidence that nutrient related algae blooms are not independent of top-down regulation. However, both threats, eutrophication and overfishing, are so far managed independently of each other by focusing either on reducing nutrient loads or defining fishing quotas for threatened species.

In a combined study using field data and evidence of two experimental studies Eriksson et al. show that decline of top-predators and nutrient load have similar and additive effects on the abundance of ephemeral algae. Both factors together increased abundance of ephemeral algae many times! The field data revealed a strong negative correlation between the abundance of fish and ephemeral algae. When fish was depleted high abundances of their prey and at the same time high cover of ephemeral algae was observed. The experiments very nicely proofed these observations. By excluding predatory fish Eriksson et al. show that (i) the abundance of small mesopredators increased, (ii) the smaller gastropod grazers became smaller, and (iii) the net production of ephemeral algae increased. Moreover, the predator effect depended on grazers and habitat complexity. In the absence of grazers predator removal had no effect on algae growth. In the absence of canopy cover, i.e. a proxy for habitat complexity ephemeral algae growth doubled.

This paper makes a strong point that to successfully combat eutrophication the so far unidirectional view on either bottom-up or top-down forces should change towards an integrated approach taking into account both factors.

Britas Klemens Eriksson, Lars Ljunggren, Alfred Sandström, Gustav Johansson, Johanna Mattila, Anja Rubach, Sonja Råberg, Martin Snickars (2009) Declines in predatory fish promote bloom-forming macroalgae. Ecological Applications: Vol. 19, No. 8, pp. 1975-1988. doi: 10.1890/08-0964.1

Tuesday, November 17, 2009

Podcasts from the Center

Looking for interviews with scientists and managers working on important ecology and conservation issues? Luckily, a new project, called the Voyage of the Beagle has recently started archiving interview podcasts. Jai Ranganathan, a postdoctoral associate at the National Center for Ecological Analysis and Synthesis started this site to promote current research and researchers and to make lively conversations about research accessible to everyone. Check it often, three new interviews will be posted every week!

The latest podcasts are fed into our blog roll on the right sidebar.

Monday, November 9, 2009

Emergent linkages in seemingly unconnected food chains

ResearchBlogging.orgFood webs are notoriously complex, and a difficult aspect of ecology is to offer a priori model-derived predictions of food web processes. There are some ecologists, such Neo Martinez and Jordi Bascompte, who have advanced our understanding of the general mechanisms of food web properties and dynamics through tools such as network theory. Such advanced approaches rely on direct interactions among species, or at least indirect interactions that are mediated through changes in abundance of different network players. However, what is missing from our general understanding of food web interactions is the role that behavioral responses can affect patterns of consumption and network connectivity.

Washington State University ecologists, Renée Prasad and William Snyder convincingly show how behavioral responses to predation can fundamentally alter food web interactions and link previously independent predator-prey interactions. They used two spatially independent insect predator-prey links in a novel, factorially-designed experiment. The two food chains consisted of a ground-based one, where ground beetles consume fly eggs and a plant-based one, where green peach aphids feed on the plants and are consumed by lady beetles. Under the ground-based chain only, the ground-based chain plus aphids, or ground-based chain plus lady beetles, the ground beetles consume a high proportion of the fly eggs. However, when both aphids and lady beetles are present, aphids respond to lady beetles by dropping off the plants and the ground beetles switch from consuming fly eggs to aphids. Under this last treatment, very few fly eggs are consumed, fundamentally altering the strength of the linkages in the two food chains and connecting them together.

This research highlights the inherent complexity in trying to understand multispecies systems, where the actors potentially have behavioral responses to other species, changing the nature of interactions. These types of responses may also generally increase the connectedness of such networks, which may result in more stable food webs, but this would need to be empirically tested. Regardless, this type of experiment offers food-for-thought to scientists trying to work general processes into a broad understanding of food web dynamics.

Prasad, R., & Snyder, W. (2009). A non-trophic interaction chain links predators in different spatial niches Oecologia DOI: 10.1007/s00442-009-1486-7

Monday, November 2, 2009

Eco-label Promotes Biodiversity on Farms

At first glance, potato farms might seem like an unlikely candidate for conservation efforts.

But Wisconsin researchers are demonstrating that biodiversity can be restored even in the midst of large-scale farming.

Paul Zedler, professor of Environmental Studies at the University of Wisconsin (UW)-Madison, and his colleagues are working with potato farmers to restore pre-settlement habitats on growers’ lands.

In central Wisconsin, 42,600 acres are devoted to potatoes. Since the landscape is dominated by agriculture, some proportion of farmland must be set aside for conservation to preserve biodiversity in this part of the state.

Restoration is a requirement of the Wisconsin Healthy Grown potato program, a partnership between UW–Madison, the Wisconsin Potato and Vegetable Growers’ Association, and NGOs such as the International Crane Foundation, Defenders of Wildlife, and the World Wildlife Fund.

The groundwork for the Healthy Grown program was laid out in the 1980s, when a group of potato growers voluntarily discontinued use of the high-risk pesticide aldicarb. The farmers turned to UW-Madison researchers for pest-management advice. This grassroots movement eventually drew attention from conservation agencies.

To be certified under the Healthy Grown eco-label, potatoes must be grown under a set of standards that restrict pesticide and fertilizer use. The program was able to draw from an extensive body of UW-Madison research to guide the formulation of these in-field standards. But farmers and environmentalists were interested in doing more.

Since the program's conception, growers had expressed interest in managing their farms as whole ecosystems rather than just focusing on crop production on a field by field basis. At the same time, the NGOs saw the program as an opportunity to bring farmland into regional-scale conservation plans.

Satisfying this interest in developing a conservation standard for the eco-label was challenging for researchers because fewer precedents existed. Even the largest and most well-known eco-label, USDA Organic, does not include a conservation requirement in its certification standards.

Zedler and his colleagues looked to the Nature Conservancy, which had established a system for making strategic conservation decisions and measuring conservation success at sites where the objective is to improve biodiversity on whatever land can be spared from intensive human use.

Potato farms in central Wisconsin are unusual in their tendency to contain significant patches of marginal land without crops because these patches cannot be irrigated – a necessary factor in growing potatoes. The result is a complex mosaic of land in which remnant patches of disturbed natural habitat are isolated within an agricultural matrix. Zedler and his colleagues focused their research efforts on these patches of non-crop land.

Their research suggests that prescribed burns and control of invasive plant species can help restore disturbed non-crop land to the habitats that characterized central Wisconsin before European settlement: prairie, oak-pine savannah, and sedge meadow.

Thus far, the Healthy Grown program has restored more than 400 acres of privately owned farmland. According to Zedler and his colleagues, farmers’ strong ties to their land motivate their commitment to the conservation standard of the Healthy Grown eco-label.

Zedler, P. H., T. Anchor, D. Knuteson, C. Gratton, and J. Barzen. 2009. Using an ecolabel to promote on-farm conservation: the Wisconsin Healthy Grown experience. International Journal of Agricultural Sustainability 7(1): 61-74. DOI:10.3763/ijas.2009.0394

(Image courtesy of FotoosVanRobin at flickr under a Creative Commons license)