Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.
Sci Total Environ. 2010 Mar 15;408(8):1888-901. doi: 10.1016/j.scitotenv.2009.11.050. Epub 2010 Feb 18.
Our hypothesis is that a high diversity of dominant life forms in Tennessee forests conveys resilience to disturbance such as climate change. Because of uncertainty in climate change and their effects, three climate change scenarios for 2030 and 2080 from three General Circulation Models (GCMs) were used to simulate a range of potential climate conditions for the state. These climate changes derive from the Intergovernmental Panel on Climate Change (IPCC) "A1B" storyline that assumes rapid global economic growth. The precipitation and temperature projections from the three GCMs for 2030 and 2080 were related to changes in five ecological provinces using the monthly record of temperature and precipitation from 1980 to 1997 for each 1km cell across the state as aggregated into the provinces. Temperatures are projected to increase in all ecological provinces in all months for all three GCMs for both 2030 and 2080. Precipitation differences from the long-term average are more complex but less striking. The forest ecosystem model LINKAGES was used to simulate conditions for five ecological provinces from 1989 to 2300. Average output projects changes in tree diversity and species composition in all ecological provinces in Tennessee with the greatest changes in the Southern Mixed Forest province. Projected declines in total tree biomass are followed by biomass recovery as species replacement occurs in stands. The Southern Mixed Forest province results in less diversity in dominant trees as well as lower overall biomass than projections for the other four provinces. The biomass and composition changes projected in this study differ from forest dynamics expected without climate change. These results suggest that biomass recovery following climate change is linked to dominant tree diversity in the southeastern forest of the US. The generality of this observation warrants further investigation, for it relates to ways that forest management may influence climate change effects.
我们的假设是，田纳西州森林中占主导地位的生命形式多样性很高，这意味着它们对气候变化等干扰具有恢复力。由于气候变化及其影响存在不确定性，我们使用了三个全球环流模型（GCMs）的三个气候变化情景来模拟该州潜在的气候变化范围。这些气候变化源自政府间气候变化专门委员会（IPCC）“A1B”情景，假设全球经济快速增长。三个 GCMs 对 2030 年和 2080 年的降水和温度预测与五个生态省的变化相关，使用每个 1km 格网在整个州内的温度和降水的月记录，这些记录汇总为生态省。在所有三个 GCMs 中，所有生态省在所有月份的温度都预计会升高，无论是在 2030 年还是在 2080 年。降水与长期平均值的差异更为复杂，但不那么显著。LINKAGES 森林生态系统模型用于模拟五个生态省从 1989 年到 2300 年的情况。平均输出项目预测了田纳西州所有生态省的树木多样性和物种组成的变化，其中变化最大的是南方混合林省。预计总树木生物量会下降，随后随着物种在林分中的更替，生物量会恢复。与其他四个省相比，南方混合林省的主导树种多样性减少，整体生物量也较低。与没有气候变化的情况下预计的森林动态相比，本研究中预测的生物量和组成变化有所不同。这些结果表明，气候变化后生物量的恢复与美国东南部森林中主导树种的多样性有关。这一观察结果的普遍性值得进一步研究，因为它关系到森林管理可能影响气候变化影响的方式。
