Simulated distribution of vegetation types in response to climate change on the Tibetan Plateau

Abstract

Questions: What is the relationship between alpine vegetation patterns and climate? And how do alpine vegetation patterns respond to climate changes? Location: Tibetan Plateau, southwestern China. The total area is 2 500 000 km 2 with an average altitude over 4000 m. Methods:The geographic distribution of vegetation types on the Tibetan Plateau was simulated based on climatology using a small set of plant functional types (PFTs) embedded in the biogeochemistry-biography model BIOME4. The paleoclimate for the early Holocene was used to explore the possibility of simulating past vegetation patterns. Changes in vegetation patterns were simulated assuming continuous exponential increase in atmospheric CO 2 concentration, based on a transient ocean-atmosphere simulation including sulfate aerosol effects during the 21st century. Results: Forest, shrub steppe, alpine steppe and alpine meadow extended while no desert vegetation developed under the warmer and humid climate of the early Holocene. In the future climate scenario, the simulated tree line is farther north in most sectors than at present. There are also major northward shifts of alpine meadows and a reduction in shrubdominated montane steppe. The boundary between montane desert and alpine desert will be farther to the south than today. The area of alpine desert would decrease, that of montane desert would increase. Conclusions: The outline of changes in vegetation distribution was captured with the simulation. Increased CO2 concentration would potentially lead to big changes in alpine ecosystems.

Impacts of climate change on Chinese ecosystems: key vulnerable regions and potential thresholds

“…The disappearance of permafrost would accelerate desertification (Ni 2000). The improved BIOME4 model was also applied to the Tibetan Plateau under the HadCM3 climate scenario during the twenty-first century (Song et al 2005). Increased CO 2 concentration would potentially lead to big changes in alpine ecosystems.…”

Simulating Alpine Tundra Vegetation Dynamics in Response to Global Warming in China

“…The structure of the model is generally applicable to other situations, but the particular factors and constraints used in this model are unique to the Haibei alpine tundra ecosystem. Global warming has strong effects on the alpine ecosystems in terms of altering the biomes and ecosystem biodiversity (Cao & Woodward, 1998;Ni, 2000;Song et al, 2005. The alpine ecosystem in the region of the Qinghai-Tibetan plateau is sensitive and vulnerable to the changing climate (Zhang & Welker, 1996;Kato et al, 2006).…”

“…We present a changing alpine tundra vegetaion using Vegetation Dynamic Simulation Model (VDSM) integrated with scenarios of global temperature increase of 1 to 3°C (Zhang et al, 2008). With BIOME4 model (Song et al, 2005), we illustrate the vegetation biomass changes and the vegetation distribution dynamics in the region of Qinghai-Tibetan Plateau in responses to global warming.…”

“…Ni (2000) simulated biomes on the Tibetan Plateau using the improved BIOME3 model (BIOME3-China) under the present climate conditions, as well as under a scenario with a CO 2 concentration of 500 ppmv. A combined biogeography biochemistry model, BIOME4 (Kaplan et al, 2003) was improved to simulate the alpine vegetation changes at the biome level (Song, et al, 2005). In this chapter, we review the important ecological findings from simulated environmental changes on the alpine tundra vegetation (Zhang & Welker, 1996).…”

Trends in temperature and precipitation on the Tibetan Plateau, 1961–2005

“…For example, one model shows that if temperature were to increase by 4°C and precipitation by 10%, by the year 2100 mountain vegetation in the southeast TP would become forest-dominated, the total area of alpine meadow and high mountain grassland would decrease by 50%, the vegetation and snow lines would move to higher altitudes, the permafrost would melt, glaciers would shrink and lakes would diminish (Fan et al 2005). Another model suggests that enhanced warming would cause a northward shift of the alpine meadow and a reduction in shrub-dominated alpine steppe (Song et al 2005). This paper presents the basic characteristics of temperature and precipitation in different climatic zones from 1961-2005 in order to obtain an understanding of the effects of climate change in the 'Third Pole'.…”