Responses of boreal trees to global change: acclimate, migrate or disappear?

自工业革命以来，大气中的二氧化碳浓度一直在增加，在可预见的未来还将继续增加。上升的二氧化碳影响植物的生理、生长和分布。研究表明，二氧化碳上升引起的气候变化将在北方地区最为突出。北方森林是地球上最大的陆地生态系统。它的生态生理活动可以对地球的环境条件产生深远的影响。生态生理过程反过来又受气候和土壤条件的控制。虽然气候变量和一些土壤因子的影响研究相对广泛，但土壤温度如何与其他因子相互作用影响北方乔木对气候变化的响应尚不清楚。北方地区的土壤温度变化很大。因此，了解其潜在影响对于更好地了解北方森林如何应对气候变化至关重要。本研究将探讨在预测的未来大气CO2浓度下，土壤温度如何与其他环境因子相互作用，影响北方重要树种的生态生理活动和生长。将开发计算机模型，将土壤条件纳入生态模型。对气候变化的反应有几种类型：迁移到其他地区，进行生理和生长调整以适应新的条件，在当前位置继续生长但性能较低或灭绝。这项研究将提供对这些反应的相对可能性的见解，并推进北方树木生态生理学的科学。北方森林是支持加拿大森林工业和旅游业的重要资源。提高对北方树木对气候变化的潜在反应的了解和预测能力，将为决策者和森林管理者提供信息，以制定更合适的适应和缓解战略。****

Atmospheric carbon dioxide concentration has been increasing since the Industrial Revolution and will continue to increase in the foreseeable future. Rising CO2 affects the physiology, growth and distribution of plants. Studies suggest that the rising CO2 induced climate change will be most prominent in the boreal region. The boreal forest is the largest terrestrial ecosystem on the earth. Its ecophysiological activities can have a profound impact on the environmental conditions of the earth. The ecophysiological processes are in turn controlled by climate and soil conditions. While the impact of climate variables and some soil factors are studied relatively extensively, it is still not clear how soil temperature may interact with other factors to influence the responses of boreal trees to climate change. Soil temperature is very variable in the boreal region. Thus understanding its potential effects is critical for a better understanding of how the boreal forest may respond to climate change. This research will examine how soil temperature will interact with other environmental factors to influence the ecophysiological activities and growth of important boreal tree species under the projected future atmospheric CO2 concentration. Computer models will be developed for incorporating soil conditions into ecological models. There are several types of responses to climate change: migrate to other areas, make physiological and growth adjustment to fit the new conditions, continue to grow at the current location but with a lower performance or become extinct. This research will provide insights on the relative likelihood of these responses and advance the science of boreal tree ecophysiology. The boreal forest is a critical resource supporting the forest industry and tourism in Canada. The improved understanding of and predicting power for potential responses of boreal trees to climate change will provide policy makers and forest managers with information to develop more suitable adaptation and mitigation strategies.****