A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on Earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area.
An ecological or environmental crisis occurs when changes to the environment of a species or population destabilizes its continued survival. Some of the important causes include:
Regime shifts are large, abrupt, persistent changes in the structure and function of ecosystems, the climate, financial systems or other complex systems. A regime is a characteristic behaviour of a system which is maintained by mutually reinforced processes or feedbacks. Regimes are considered persistent relative to the time period over which the shift occurs. The change of regimes, or the shift, usually occurs when a smooth change in an internal process (feedback) or a single disturbance triggers a completely different system behavior. Although such non-linear changes have been widely studied in different disciplines ranging from atoms to climate dynamics, regime shifts have gained importance in ecology because they can substantially affect the flow of ecosystem services that societies rely upon, such as provision of food, clean water or climate regulation. Moreover, regime shift occurrence is expected to increase as human influence on the planet increases – the Anthropocene – including current trends on human induced climate change and biodiversity loss. When regime shifts are associated with a critical or bifurcation point, they may also be referred to as critical transitions.
There are several plausible pathways that could lead to an increased extinction risk from climate change. Every plant and animal species has evolved to exist within a certain ecological niche. But climate change leads to changes of temperature and average weather patterns. These changes can push climatic conditions outside of the species' niche, and ultimately render it extinct. Normally, species faced with changing conditions can either adapt in place through microevolution or move to another habitat with suitable conditions. However, the speed of recent climate change is very fast. Due to this rapid change, for example cold-blooded animals may struggle to find a suitable habitat within 50 km of their current location at the end of this century.
F. Stuart Chapin III is a professor of Ecology at the Department of Biology and Wildlife of the Institute of Arctic Biology, University of Alaska. He was President of the Ecological Society of America (ESA) from August 2010 until 2011.
There is an ongoing decline in plant biodiversity, just like there is ongoing biodiversity loss for many other life forms. One of the causes for this decline is climate change. Environmental conditions play a key role in defining the function and geographic distributions of plants. Therefore, when environmental conditions change, this can result in changes to biodiversity. The effects of climate change on plant biodiversity can be predicted by using various models, for example bioclimatic models.
Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants (evapotranspiration). The United Nations Environment Program defines drylands as tropical and temperate areas with an aridity index of less than 0.65. One can classify drylands into four sub-types:
Katherine Jane Willis, Baroness Willis of Summertown, is a British biologist, academic and life peer, who studies the relationship between long-term ecosystem dynamics and environmental change. She is Professor of Biodiversity in the Department of Biology and Pro-Vice-Chancellor at the University of Oxford, and an adjunct professor in biology at the University of Bergen. In 2018 she was elected Principal of St Edmund Hall, and took up the position from 1 October. She held the Tasso Leventis Chair of Biodiversity at Oxford and was founding Director, now Associate Director, of the Biodiversity Institute Oxford. Willis was Director of Science at the Royal Botanic Gardens, Kew from 2013 to 2018. Her nomination by the House of Lords Appointments Commission as a crossbench life peer was announced on 17 May 2022.
The contributions of women in climate change have received increasing attention in the early 21st century. Feedback from women and the issues faced by women have been described as "imperative" by the United Nations and "critical" by the Population Reference Bureau. A report by the World Health Organization concluded that incorporating gender-based analysis would "provide more effective climate change mitigation and adaptation."
Diana Harrison Wall was an American environmental scientist and soil ecologist. She was the founding director of the School of Global Environmental Sustainability, a distinguished biology professor, and senior research scientist at the Natural Resource Ecology Laboratory at Colorado State University. Wall investigated ecosystem processes, soil biodiversity and ecosystem services. Her research focused on the Antarctic McMurdo Dry Valleys and its Wall Valley was named after her. Wall was a globally recognized leader and speaker on life in Antarctica and climate change.
Mark C. Urban is a biologist and associate professor in ecology and evolutionary biology at the University of Connecticut. His work focuses on the ecological and evolutionary mechanisms that shape natural communities across multiple spatial scales.
Eric L. Berlow is an American ecologist and data scientist. He co-founded a visual data interface company, which was acquired by Rakuten Inc. in 2016. He now runs Vibrant Data Labs, a social impact data science group currently focused the building on an open-source framework for tracking the flows of money to climate mitigation and resilience efforts on the ground. Prior to Vibrant Data Labs, Berlow was the founding director of the University of California's first science and education institute inside Yosemite National Park which facilitated efforts to leverage data for informing conservation policy and natural resource management. Berlow is internationally recognized for his research on ecological complexity, with articles in Nature, Science, and Proceedings of the National Academy of Sciences. He is best known for his TED talks on simplifying complexity and finding hidden patterns in complex data. Berlow has received a TED Fellowship, a TED Senior Fellowship, an Alexander Von Humboldt Fellowship, a National Science Foundation Post-doctoral Fellowship, and a National Center for Ecological Analysis and Synthesis Fellowship. He was named one of the top 100 Creatives by Origin magazine.
John Harte is an American ecologist and Professor of the Graduate School in the Energy and Resources Group at the University of California at Berkeley. His work includes investigation into a maximum entropy theory of ecology and long-term experiments on the effects of climate change on alpine ecology.
Erika S. Zavaleta is an American professor of ecology and evolutionary biology at the University of California, Santa Cruz. Zavaleta is recognized for her research focusing on topics including plant community ecology, conservation practices for terrestrial ecosystems, and impacts of community dynamics on ecosystem functions.
Sandra Myrna DíazForMemRS is an Argentine ecologist and professor of ecology at the National University of Córdoba, who has been awarded with the Linnean Medal for her scientific work. She studies the functional traits of plants and investigates how plants impact the ecosystem.
Jiquan Chen is a landscape ecologist, primarily focused on nutrient flux, carbon cycling, bioenergy, and grassland ecology. He currently leads the LEES lab at Michigan State University.
Aimée Classen is an American ecologist who studies the impact of global changes on a diverse array of terrestrial ecosystems. Her work is notable for its span across ecological scales and concepts, and the diversity of terrestrial ecosystems that it encompasses, including forests, meadows, bogs, and tropics in temperate and boreal climates.
Richard Simon Ostfeld is a Distinguished Senior Scientist at the Cary Institute of Ecosystem Studies in Millbrook, New York. He is best known for his work on the ecology of Lyme disease, which he began studying while monitoring the abundance of small mammals in the forests of Cary Institute property in the early 1990s.
Elisabeth Huber-Sannwald is an Austrian researcher specializing in ecosystem ecology. She is a Full Research Professor in Ecology and Global Environmental Change as well as the Department Head of Instituto Potosino de Investigación Científica y Tecnológica (IPICYT) in San Luis Potosí, Mexico.
Yiqi Luo is an ecologist specializing in systems analysis and modeling. His interests lie in terrestrial ecosystem and carbon cycle modeling, with some of his more renowned papers focused on understanding how novel methods of modeling can help to understand soil carbon dynamics. He is currently the Liberty Hyde Bailey Professor at the School of Integrative Plant Science, Soil and Crop Sciences at Cornell University.
