Global change and terrestrial plant community dynamics

Abstract

This contribution is part of a special series of Inaugural Articles by members of the National Academy of Sciences elected in 2014.Contributed by Janet Franklin, February 2, 2016 (sent for review October 8, 2015; reviewed by Gregory P. Asner, Monica G. Turner, and Peter M. Vitousek)Anthropogenic drivers of global change include rising atmospheric concentrations of carbon dioxide and other greenhouse gasses and resulting changes in the climate, as well as nitrogen deposition, biotic invasions, altered disturbance regimes, and land-use change. Predicting the effects of global change on terrestrial plant communities is crucial because of the ecosystem services vegetation provides, from climate regulation to forest products. In this paper, we present a framework for detecting vegetation changes and attributing them to global change drivers that incorporates multiple lines of evidence from spatially extensive monitoring networks, distributed experiments, remotely sensed data, and historical records. Based on a literature review, we summarize observed changes and then describe modeling tools that can forecast the impacts of multiple drivers on plant communities in an era of rapid change. Observed responses to changes in temperature, water, nutrients, land use, and disturbance show strong sensitivity of ecosystem productivity and plant population dynamics to water balance and long-lasting effects of disturbance on plant community dynamics. Persistent effects of land-use change and human-altered fire regimes on vegetation can overshadow or interact with climate change impacts. Models forecasting plant community responses to global change incorporate shifting ecological niches, population dynamics, species interactions, spatially explicit disturbance, ecosystem processes, and plant functional responses. Monitoring, experiments, and models evaluating multiple change drivers are needed to detect and predict vegetation changes in response to 21st century global change.climate change | drought | forests | global change | land-use change T errestrial plant communities include forests, woodlands, shrublands, and grasslands; they support economic activities including forestry and grazing and provide other ecosystem services (1) such as carbon sequestration and water delivery. Plant communities play a key role in global biogeochemical cycles of carbon, oxygen, water, and nitrogen, with feedbacks to the oceans, atmosphere, and climate. The distribution of animals on land is often influenced by the distribution of vegetation, and therefore, plant community dynamics affect biodiversity. Changes in the Earth's vegetation in response to climate change, and associated faunal changes, may have played a role in the evolution of the human lineage (2, 3). Thus, human populations have a vested interest in understanding rapid global change effects on terrestrial plant communities.Anthropogenic drivers of global change include rising atmospheric concentrations of CO 2 and other greenhouse gasses and associated changes in the climate, as well...

Intensifying postfire weather and biological invasion drive species loss in a Mediterranean-type biodiversity hotspot

“…Our findings are based on models that consider a range of potential drivers of change and an analysis of species' climatic niches to infer community-level responses to a/biotic change, and are consistent with multiple existing lines of evidence, including germination and seedling trials (14,15), and regional vulnerability assessments (59). This study highlights the value of detailed long-term datasets for detecting the influence of multiple global change drivers in unison and for identifying region-specific interactions among change drivers and natural ecological processes (9,34). The exacerbation of postfire mortality by increasingly severe weather extremes is likely to drive major shifts in the composition, structure, and function of fire-prone ecosystems subject to severe summer droughts and temperature extremes.…”

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“…7). Trees and forests provide critical ecological and commercial services, including impacts on global carbon cycles, species diversity, water quality, and climate regulation (8). Recent forest mortality (9,10) highlights the importance of understanding how climate change and climate change-driven disturbances may impact forests (11,12).…”