Unproductive grasslands resist climate change and help native species

William Atkins
Monday, 04 August 2008 20:56

Science - Climate

In fact, their abstract states, “Here we document this resistance in the form of: (i) constancy in the relative abundance of growth forms and maintained dominance by long-lived, slow-growing grasses, sedges, and small forbs; (ii) immediate but minor shifts in the abundance of several species that have remained stable over the course of the experiment; (iii) no change in productivity in response to climate treatments with the exception of reduction from chronic summer drought; and (iv) only minor species losses in response to drought and winter heating.”

Consequently, the researchers concluded that the changes in climate caused non-native species (both plants and animals) within the grasslands, which were poor in nutrients before and during their study, to reduce their invasive (aggressively overtaking native species) activities.

That is, native plants and animals had better chances of maintaining their health and viability within the nutrient-poor grasslands as climate changed and non-native plants and animals were more adversely affected.

In conclusion, “Overall, compositional changes induced by 13-yr exposure to climate regime change were less than short-term fluctuations in species abundances driven by interannual climate fluctuations. The lack of progressive compositional change, coupled with the long-term historical persistence of unproductive grasslands in northern England, suggests the community at Buxton possesses a stabilizing capacity that leads to long-term persistence of dominant species. Unproductive ecosystems provide a refuge for many threatened plants and animals and perform a diversity of ecosystem services.”

Dr. Fridley said, within the New Scientist article “Grassy sanctuary” (July 12-18, 2008, page 7), “The lack of nutrients stops non-native species from exploiting climate change.”

The Fridley team suggests that other nutrient-poor ecosystems around the world, such as tropical grasslands and European pastures, may also be great areas to provide a safe place to grow and maintain native plants and animals.

Specifically, the team concludes, “Our results support the view that changing land use and overexploitation rather than climate change per se constitute the primary threats to these fragile ecosystems.”

However, the research team also found that these nutrient-poor grasslands were most susceptible to increased nutrient levels, as what occurs when nutrients are introduced from agricultural runoff.