Climate as a driver of shrub expansion and tundra greening

气候是灌木扩张和苔原绿化的驱动力

基本信息

批准号：
NE/M016323/1
负责人：
Isla H. Myers-Smith
金额：
$ 68.04万
依托单位：
University of Edinburgh
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FM016323%2F1
关键词：
Climate driver shrub expansion tundra

项目摘要

Global climate change has been identified as a serious threat that has already had profound impacts on terrestrial Arctic systems. A dramatic example of this is the expansion of tundra shrubs. Shrubs are an important part of the Arctic carbon cycle and major contributors to feedbacks facilitating high-latitude climate warming. The April 2014 IPCC Impacts report assigned a high confidence in the detection of an increase in shrubs in Arctic ecosystems and attributes shrub expansion to climate warming. However currently, the relative importance of climate versus other biological or environmental factors as drivers of tundra shrub growth and expansion remains poorly understood. Over the next century tundra ecosystems are predicted to warm by 2 - 10C. A significant unknown is whether shrubs will rapidly respond to warming conditions, or whether environmental factors such as water availability, nutrient limitation, herbivory, pathogen outbreaks, or fire will begin to limit the rate of future vegetation change. To address this knowledge gap, we propose to: 1) quantify the importance of climate as a driver of tundra shrub growth and expansion at sites across the tundra biome, 2) test the correspondence between plot-scale field observations with remotely-sensed data of tundra greening, 3) analyse the correlations between time series of shrub growth, tundra greening and climate and 4) assess the agreement between patterns of tundra greening and vegetation change at the landscape-scale.Our key objectives are:1) To scale tundra vegetation change-climate interactions from plot to biome: We will integrate locally-collected data from sites around the Arctic and remotely-sensed data to test a) whether growing season temperatures are the primary driver of tundra vegetation change and b) whether remotely-sensed greening data capture a signal that correlates with spatial and temporal variation in local-scale shrub expansion. 2) To link patterns of tundra greening and vegetation change at the landscape scale: To scale from plot to biome at our focal research site Herschel Island, we will collect high spatial resolution (< 10 cm pixel) tundra greening data using an unmanned aircraft system (UAS) to compare with vegetation monitoring data, plant trait measurements, disturbance rates and terrain characteristics. 3) To improve predictions of tundra vegetation change: We will integrate our research findings to make data-driven predictions of shrub increase across the tundra biome. We will conduct a data synthesis workshop in 2017 to integrate our research objectives, evaluate the future research priorities and synthesize our findings.This proposed research is both timely and urgent, as the required biome-scale datasets have only recently become available in long-enough duration, and the technologies, methodological approaches and statistical techniques are only now refined sufficiently to test mechanisms of shrub expansion across spatial and temporal scales. Our findings will provide fundamental insights into the drivers of shrub growth and tundra greening and will enable improved predictions of future tundra vegetation change.The proposed research will result in the generation of a publically available dataset that will provide key estimates of tundra vegetation change to the broad scientific community. We will disseminate results through timely publications in internationally recognized journals and presentations at major conferences, knowledge exchange, ecological assessments, public engagement, and media. Lastly, the project will provide comprehensive training, mentorship and networking opportunities for early career researchers.

全球气候变化已被确定为严重的威胁，已经对陆地北极系统产生了深远的影响。一个戏剧性的例子是苔原灌木的膨胀。灌木是北极碳循环的重要组成部分，是促进高纬度气候变暖的反馈的主要贡献者。 2014年4月的IPCC影响报告对检测北极生态系统中灌木增加的发现具有很高的信心，并将灌木膨胀到气候变暖中。但是，目前，随着苔原灌木生长和扩张的驱动因素，气候与其他生物学或环境因素的相对重要性仍然很少了解。在下一个世纪，苔原生态系统预计将在2-10C上加热。一个重要的未知是灌木是否会迅速响应变暖状况，还是诸如水的可用性，养分限制，食草动物，病原体爆发或火灾等环境因素是否会开始限制未来植被变化的速度。为了解决这一知识差距，我们建议：1）量化气候作为苔原灌木生长的驱动力的重要性和在整个苔原生物群落的地点的扩张驱动力的驱动力，2）测试图与绿绿色的近距离观察之间的情节尺度观测之间的对应关系，3）分析绿色绿色和tumimate绿色的蔬菜的相关性，3） change at the landscape-scale.Our key objectives are:1) To scale tundra vegetation change-climate interactions from plot to biome: We will integrate locally-collected data from sites around the Arctic and remotely-sensed data to test a) whether growing season temperatures are the primary driver of tundra vegetation change and b) whether remotely-sensed greening data capture a signal that correlates with spatial and temporal variation in local-scale灌木膨胀。 2）为了在景观量表上链接苔原绿化和植被的变化：为了在我们的焦点研究站点赫歇尔岛（Herschel Island）从情节到生物群，我们将使用无人飞机系统（UAS）（UAS）收集高空间分辨率（<10 cm Pixel）苔原绿色数据，以与植被数据，植物特征测量率和领域的植物特征测量率和领域相比。 3）为了改善苔原植被变化的预测：我们将整合研究结果，以使整个苔原生物群落中的灌木增加。我们将在2017年举办数据合成研讨会，以整合我们的研究目标，评估未来的研究优先级并综合我们的发现。这项拟议的研究既及时又紧迫，因为所需的生物群规划数据集仅在远景持续时间内才可以使用，并且仅在远处进行了范围，并且仅在技术，方法论方法和统计技术方面进行了范围，并跨越了范围的范围，并遵循了范围的范围。我们的发现将提供对灌木生长和苔原绿化驱动因素的基本见解，并能够改善对未来苔原植被变化的预测。拟议的研究将导致产生公开可用的数据集，该数据集将提供对苔原植被变化的关键估计，从而为广泛的科学社区提供了关键的估计。我们将通过在主要会议，知识交流，生态评估，公众参与和媒体上及时出版在国际认可的期刊和演讲中及时发布结果。最后，该项目将为早期职业研究人员提供全面的培训，指导和网络机会。