EAPSI: Does Clay Content in Soil Exacerbate the Effects of Climate Change in Arid Ecosystems?

气候变化是物种范围扩大或缩小的主要因素之一。通过气候模型，研究人员能够预测当地范围内的温度变化和降雨模式。然而，为了确定这些变化将对植物群落产生什么影响，需要在气候模型和现场植物响应变量之间建立联系。两者的结合创造了物种分布模型。在物种目前受水限制的世界干旱地区，预测物种分布模型对于了解本土植物物种在不断变化的气候中的生存至关重要。这项研究将提供有关土壤-水-植物关系的信息，这些信息将被纳入预测模型，以评估在全球气候变化存在时的景观变化。这项研究将与澳大利亚维多利亚州墨尔本拉特洛比大学的约翰·摩根博士合作进行。该研究项目的主要问题是：土壤中高粘粒含量是否会通过植物水分胁迫增加木本灌木的死亡率。该项目涉及两个研究目标：1)遥感数据的空间采样；2)相应的野外研究。在田间，将测量临界土层的粘粒含量、灌木茎水势、土壤入渗量和土壤容重。粘土含量和植物水分胁迫之间的相关性将与美国西部其他旱地地区进行比较。这些数据将被添加到该地区的遥感图像上，并与其重叠。这些结果将显示气候变化如何通过土壤粘粒含量的影响来缓和，可能会影响两个不同旱地生态系统中的群落组合。这些数据将为气候和水模型预测濒危物种提供信息。几项研究预测，灌木的分布将随着气候变化而增加。如果灌木的增加或减少通过粘土含量与降水制度联系在一起，包容性模型将能够更好地预测灌木受到威胁的地区。该奖项由东亚和太平洋夏季学院项目资助一名美国研究生的暑期研究，由NSF和澳大利亚科学院联合资助。

Climate change is one of the leading factors behind the range expansion or contraction of species. Through climate models, researchers are able to predict temperature change and rainfall patterns on a local scale. However, to determine what effect these changes will have on plant communities, there needs to be a connection between climate models and in situ plant response variables. The combination of both create species distribution models. In dryland regions of the world where species are currently water-limited, predictive species distribution models are critical to understanding the survival of indigenous plant species in the changing climate. This research will provide information about soil-water-plant relationships, which will be incorporated into predictive models to assess landscape changes in the presence of global climate change. Research will be conducted in collaboration with Dr. John Morgan from La Trobe University in Melbourne, Victoria, Australia.The main question of this research project is: does high clay content in soil increase woody shrub mortality through plant-water stress. This project involves two research aims: 1) spatial sampling of remotely-sensed data, and 2) corresponding field studies. In the field, clay content in critical soil layers, stem water potential of shrubs, soil infiltration, and soil bulk density will be measured. Correlations will be formed between clay content and plant-water stress which will be compared to other dryland regions in the western United States. These data will be added to, and overlayed with, remote sensing images of the area. These results will show how climate change, moderated through the effects of soil clay content, may affect community assemblage in two different dryland ecosystems. These data will inform climate and water models in their prediction for species at risk. Several studies have predicted that shrub distributions will increase with climate change. If shrub increase or decline is linked to precipitation regimes through clay content, inclusive models will be better able to predict areas where shrubs are threatened. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.