What do zebra and kangaroos have in common? At first glance, not much -- they aren't even found in the same part of the world. But here's one thing they do share: Both are part of the Nutrient Network, an innovative research cooperative spanning six continents that represents the first time anyone has used standardized ecological methods and measurements on such a global scale.
Coordinated through a University of Minnesota Institute on the Environment Discovery Grant, NutNet, as it is affectionately called, develops and carries out standardized experiments to understand the effects of fertilization and other variables such as grazing on grasslands -- land dominated by nonwoody vegetation.
"What makes NutNet unique is that data are collected using the same protocols across different landscapes," says NutNet coordinator Eric Lind. "These data are allowing us to ask general questions like, 'What is controlling diversity and productivity?' 'How are human activities changing diversity?' 'How do these changes impact the environment further on down the road?'"
Two recent articles in the journal Nature present NutNet findings on the effects of fertilization on diversity and stability of ecosystems and on the role sunlight and herbivores play in controlling diversity of grassland plants. It turns out that increasing fertilizer -- by direct application or as a side effect of human industrial activities -- decreases diversity when some plants are more successful and taller than others, thereby outcompeting them for light. The presence of herbivores such as rabbits, sheep, zebra or kangaroos can level the field -- no pun intended -- minimizing the effects of increased nutrients by nibbling down the taller plants, allowing more light to reach other species.
The peer-to-peer scientific collaborative spirit of NutNet can serve as an example for scientists approaching seemingly overwhelming global questions. "Many of the questions being asked by scientists and policy makers require answers that are relevant at the global scale," says NutNet co-founder Elizabeth Borer, an associate professor in the University's College of Biological Sciences. "Our approach is starting to become a model for others."
In addition to supporting research and data coordination, the IonE Discovery Grant supports expanding the network science approach to incorporate other kinds of research, such as plant traits and agricultural management.
"The grant will allow us to help other scientists ask entirely different questions using our cooperative approach," says Borer. "The expansion of this project promises to increase our understanding of global ecosystems."
Materials provided by University of Minnesota Institute on the Environment. Original written by Monique Dubos. Note: Content may be edited for style and length.
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