GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]

Higher plant species richness may not be enough to protect ecosystems from the worst impacts of climate extremes

Studies on mild fluctuations in weather have provided support for the idea that higher biodiversity results in more stable functioning of ecosystems, but critical appraisal of the evidence from extreme event studies is lacking.

Higher plant species richness is not always sufficient to reduce ecosystem vulnerability to climate extremes, as shown in a comprehensive literature analysis published in the Journal of Ecology.

While biodiversity is under threat around the globe, the number of extreme weather events is on the rise as a direct consequence of climate change. Researchers from several institutes around Europe have now looked into the scientific literature that addresses these global changes to examine the interactions between biodiversity and extreme weather events.

They sought to find out whether and how increased biodiversity may help to uphold the functioning of ecosystems in the face of climate extremes. In other words, can biodiversity help to avert the worst effects of droughts, heat waves and extremely wet weather? The answer, it turns out, is not cut-and-dried. Available evidence from herbaceous systems indicates mixed effects of species richness on biomass stability to extremely wet and dry events.

Why doesn't plant species richness play a consistently beneficial role in ensuring that the functioning of ecosystems is better maintained under climate extremes? The authors provide several explanations for this unexpected finding. First of all, it seems that biodiversity may not offer as much protection if the event in question is very extreme: buffering mechanisms which drive ecosystem resistance, such as compensation by better-adapted species or species taking over the functional role of others (functional redundancy), may simply be overwhelmed in such cases.

However, as lead author Hans De Boeck from the University of Antwerp points out: "Biodiversity may still be important, as it has been shown to speed up recovery of plant productivity after an extreme event."

Secondly, the cause of biodiversity decline may confound biodiversity-stability effects. Unlike in artificially-assembled, experimental systems, widely-observed eutrophication (nutrient enrichment) caused by intensive agriculture, traffic and industry often leads to impoverished ecosystems with few but fast-growing species that are less able to cope with adverse climatic conditions such as drought. Reducing eutrophication and/or maintaining a greater diversity of species with different growth rates within ecosystems could lead to more stable systems that are better able to face extremes.

Finally, species richness may not be the most relevant indicator of 'biodiversity' when studying biodiversity-stability relationships. General patterns of biodiversity effects may be more apparent if scientists consider the diversity in plant traits rather than simply species numbers. "Diversity metrics can include a variety of properties of trait distributions, but studies have only just scratched the surface on the value of these different metrics for extreme event science," says De Boeck.

In order to better harness the benefits of biodiversity for sustained ecosystem function, the authors suggest that future research should focus on understanding the underlying mechanisms of diversity-stability relationships in the face of extreme events. The study presented here highlights current knowledge gaps and provides research recommendations so that ecologists can gain a deeper understanding of the linkages between biodiversity and ecosystem stability in a changing world.

Read the paper: Patterns and drivers of biodiversity-stability relationships under climate extremes.

Article source: British Ecological Society.


Plant mothers 'talk' to their embryos via the hormone auxin

While pregnancy in humans and seed development in plants look very different, parallels exist -- not least that the embryo develops in close connection with the mother. In animals, a whole network of signals from the mother is known to influence embryo development. In plants, it has been clear for a while that maternal signals regulate embryo development. However, the signal itself was unknown -- until now. Plant scientists at the Institute of Science and Technology Austria (IST Austria), Central European Institute of Technology (CEITEC) and the University of Freiburg have now found that a plant hormone, called auxin, from the mother is one of the signals that pattern the plant embryo. Their study is published in Nature Plants.

Archaeologists discover bread that predates agriculture by 4,000 years

At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals, and thus contributed to the agricultural revolution in the Neolithic period.

Climate change-induced march of treelines halted by unsuitable soils

New research from the University of Guelph is dispelling a commonly held assumption about climate change and its impact on forests in Canada and abroad.