Too much water, fertilizer bad for plant diversityMarch 27, 2007Too much of multiple good things - water or nutrients, for example - may decrease the diversity of plant life in an ecosystem while increasing the productivity of a few species, a UC Irvine scientist has discovered. This finding provides a new explanation for why grasslands, lakes and rivers polluted with nitrogen and phosphorus, usually from agriculture, contain a limited number of plant species. For example, where the Mississippi River empties into the Gulf of Mexico, the water contains low levels of oxygen and high levels of nitrogen and phosphorus used in fertilizers resulting in reduced plant diversity. "Our results show nutrient pollution can cause loss of plant species from a habitat that can persist for more than 100 years," said W. Stanley Harpole, postdoctoral researcher in ecology and evolutionary biology at UCI and first author of the study. "This means human actions that simplify habitats can lead to long-term loss of biodiversity." This study appeared March 25 in the online edition of the journal Nature. The findings are based on experiments conducted at the University of California's Sedgwick Reserve in the Santa Ynez Valley. Researchers applied combinations of water and nutrients - including nitrogen, phosphorus and cations - to plots of grassland and found that areas treated with all of the resources had the fewest number of species but the highest productivity of a select few plant types. When the many resources that plants compete for become overly abundant, the environment simplifies, and an emphasis is placed on a single environmental factor such as space or sunlight. Only a few species best adapted to the new environmental conditions will thrive, Harpole said. The experiment, combined with an analysis of a similar 150-year-old study, supports the scientists' theory that plant diversity is directly related to the number of limiting factors such as levels of nitrogen, phosphorus, potassium and water. G. David Tilman, professor of ecology at the University of Minnesota, collaborated with Harpole on this research. The study was supported by the Andrew W. Mellon Foundation. University of California, Irvine |
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| Related Plant Diversity Current Events and Plant Diversity News Articles Plant fossils give first real picture of earliest Neotropical rainforests A team of researchers including a University of Florida paleontologist has used a rich cache of plant fossils discovered in Colombia to provide the first reliable evidence of how Neotropical rainforests looked 58 million years ago. The first neotropical rainforest was home of the Titanoboa Smithsonian researchers working in Colombia's Cerrejón coal mine have unearthed the first megafossil evidence of a neotropical rainforest. Climate change may spell demise of key salt marsh constituent Global warming may exact a toll on salt marshes in New England, but new research shows that one key constituent of marshes may be especially endangered. Isolated forest patches lose species, diversity Failing to see the forest for the trees may be causing us to overlook the declining health of Wisconsin's forest ecosystems. Forest inventories in Oregon include more than trees The first 5-year forest inventory report for Oregon's private and public lands is now available to the public: Oregon's Forest Resources, 2001-2005: Five-Year Forest Inventory and Analysis Report. Emerging model organisms featured in CSH Protocols Biological research has long relied on a small number of model organisms, species chosen because they are amenable to laboratory research and suitable for the study of a range of biological problems. Field of the future -- ecological experiment simulates conditions in 2100 A new experiment to find out how British plant ecosystems may be affected by future changes to climate and biodiversity is underway at Imperial College London. Vine invasion? UWM ecologist looks at coexistence of trees and lianas Among the hundreds of species of woody vines that University of Wisconsin-Milwaukee ecologist Stefan Schnitzer has encountered in the tropical forests of Panama, the largest has a stalk nearly 20 inches in circumference. Can tomatoes carry the cure for Alzheimer's? The humble tomato could be a suitable carrier for an oral vaccine against Alzheimer's disease, according to HyunSoon Kim from the Korea Research Institute of Bioscience and Biotechnology (KRIBB) in Korea and colleagues from Digital Biotech Inc. and the Department of Biological Science at Wonkwang University. Although their research1, just published online in Springer's journal Biotechnology Letters, is still in the early stages, it is a promising first step towards finding an edible vaccine against the neurodegenerative disease. Climate change could severely impact California's unique native plants The native plants unique to California are so vulnerable to global climate change that two-thirds of these "endemics" could suffer more than an 80 percent reduction in geographic range by the end of the century. More Plant Diversity Current Events and Plant Diversity News Articles |
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