Warning message

The subscription service is currently unavailable. Please try again later.

Science on the pulse: Top reads from February and March Part II

Compelling discussion, commentary, stories on agriculture within thriving ecosystems.

This post is part of a series called Science on the Pulse that highlights the latest literature on Ecosystem Services and Resilience.

With so much great literature on ecosystem services these two months, here is the second part to our Science on the pulse series for February and March. You can read the predecessor of this post here.

Photo Credit: Lockhaven_just back on Flickr            


The Planetary Boundaries 2.0 paper that we featured in our January blog highlighted the conservation of genetic diversity and loss of functional diversity as integral to the biosphere integrity boundary. In Ecology, Wolf and Zavaleta find evidence that Species traits outweigh nested structure in driving the effect of realistic biodiversity loss on productivity, making the case that functional diversity is an important driver of ecosystem service provision.

Steinauer et al. present their Plant diversity effect on soil microbial functions and enzymes are stronger than warming in a grassland experiment. What is novel in the soil biodiversity world is the use of enzyme detection as a surrogate for soil microbial functional diversity – a much more direct measure of trait-to-service relationships than many functional traits studied in plant ecology. This study demonstrates that soil microbial communities appear to be largely resilient to soil temperature changes, with plant diversity exerting greater control on soil community composition and their services. Similarly, Ward et al. found that vegetation exerts a greater control on litter decomposition than climate warming in peatlands. Both studies raise interesting questions about how species composition in tropical agricultural or agroforestry systems might foster soil functions.

Termites are getting their share of glory. Bonachela et al. report that termite mounds can increase the robustness of dryland ecosystems to climate change by affecting soil properties. While it easy to consider termite mounts as individual features, a landscape view shows that the area around termite mounds are hotspots of plant productivity and act essentially as an “insurance” policy against climate change by protecting vegetation from water scarcity (also see Africa’s soil engineers: Termites).

Sticking to biodiversity and climate change, Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC), has taken to changing his signature green tie for a red one when attending the Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES) plenary. Red for danger was the explanation. Nature’s IPBES commentary discusses how most of the world’s remaining biodiversity is in developing countries. Development programs, including WLE, need to take into account the impacts of development on wild biodiversity in addition to the services they provide.

Agroecology for Hippies, Hipsters, and real action towards sustainability 

Many ecosystem services and disservices are provided by biodiversity in agricultural landscapes, including pollination, pest control, and harbouring seed predators. Two papers in the Journal of Applied Ecology caught our attention this time around. Schäckermann et al. find that natural habitat does not mediate vertebrate seed predation as an ecosystem dis-service to agriculture and emphasize that where seed predators are concerned, specific studies need to be done on species behavior and feeding patterns.

Ok, I admit it, I have stated in public that the problem with cultural ecosystem services is that they serve as the dumping ground for anything that does not fit anywhere else, and thus like the intrinsic value of nature (which I do personally value), are very difficult to include in management decisions despite their importance. Gould et al. are trying to tackle this through a protocol for eliciting nonmaterial values through a cultural ecosystem services frame. Using interview techniques, the protocol provides a useful methodology for describing cultural services and their values. Great for those working in Participatory Action Research (and nice to see Gretchen Daily from the WLE steering committee as a co-author).

Think you’re stressed at work, it may be worse for bees and the pollination services they provide. Pollination is an ecosystem service of increasing concern and interest, in part because it contributes to crops that are critical for dietary diversity. Goulson et al. provide a review in Science on bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Maintaining critical pollination services will require interventions that address these multiple stressors including adopting sustainable farming methods, incorporating flower-rich habitat in agricultural land, and effective quarantine on honeybee movements.

Wild bees and european bees were also studied in Wisconsin apple orchards by Mallinger and Graton, who found that species richness of wild bees, but not the use of managed honey bees, increases fruit set of a pollinator-dependent crop. This seems like a fantastic and classic example of diversity evening out gaps by covering more niches. Looking at social drivers of colony collapse, Perry et al. found that rapid behavioral maturation accelerates failure of stressed honey bee colonies, or in other words, as adults in a bee colony are lost, young bees are forced to forage earlier, but are less successful foragers and have a greater mortality rate than adults. This feedback loop accelerates colony collapse.

Getting down and dirty 

It’s the International Year of Soils, and Wall and Six (shout out to a fellow Belgian and UC Davis mafia member) ask us to give soils their due. Probably one of our most important yet least appreciated ecosystems, Wall and Six highlight that “we can’t breath, eat, drink, or be healthy without sustainably managing soils”, or in the words of Theodore Roosevelt: the nation that destroys its soils, destroys itself.

One of WLE’s flagships focuses on Resource Recovery and Reuse (RRR), that is, rather than flushing nutrients down the drain, let’s close the loop and put nutrients back on fields and in natural systems. A brief correspondence in Nature asks us to bring on the sewage when considering the beneficial effects of biochar on soils to enhance crop productivity (that is, suggesting that we can make biochar from human sewage, essentially what WLE’s RRR is doing!). This might replace the costs of constructing costly sewage-treatment infrastructure, and we hope, that this could be a case of a leapfrogging technology in developing countries.

Wang et al. provide a more detailed probabilistic evaluation of integrating resource recovery into wastewater treatment to improve environmental sustainability in PNAS. What we like about this paper is the disaggregation of developed and developing country contexts. The authors found that wastewater reuse can increase the environmental performance of waste water treatment plants by as much as 60% in developing countries, even though they highlight substantial risks of failure.

The Pressure Cooker

Drought is featuring a lot in both the media and scientific literature. We expect 2015 to be a big year for drought in both Brazil and California. Drought triggers alarms in Brazil’s biggest metropolis was featured in Science’s February 20 issue. With more than 85 million people living in the Sao Paulo region, a 2-year drought is driving the government to identify voluntary and regulatory mechanisms to conserve water. Some argue that this drought is the combined effect of climate change and deforestation in the north. Devaraju et al. support this with evidence from Southeast Asia on the effects of large-scale deforestation on precipitation in the monsoon regions, that argues remote effects from large-scale deforestation are more important than local ones. California is in a similar situation, facing its fourth year of drought, and record low snowpack levels. Just this week Governor Jerry Brown mandated a 25% reduction in water use by all water supply agencies.

Both regions will be important test cases for resilience in the face of intense environmental drivers. It will be critical to see whether policy decisions will ultimately push these regions beyond environmental thresholds, or whether policymakers will focus on long term resilience and adaptability.

Agriculture is a major user of water. Rockström (Chair of the WLE Steering Committee) and Falenmark published a commentary in Nature calling for an increase in water harvesting in Africa. This is relevant to a lot of our work in WLE and succinctly captures the major challenges around water harvesting and use in sub-saharan Africa. It would take very little effort to translate these challenges into ecosystem service-based approaches to water and carbon storage.

It’s easy to talk about sustainability, but CGIAR scientists are not known for their aversion to flying (although I’ve found this to be the best place to hide from email). Flights add up, and are important contributor to greenhouse gas emissions. Nature’s March 19 editorial for A clean, green science machine highlights the need for improved virtual meetings, conferencing, and collaborations. A greater and better use of online tools will take some training and adaptability, but in the end, could be more inclusive, better for our budgets, and for our environment and families.

That’s all for February and March! Do send us your feedback and references for the April issue.