Integrating measures of grassland function using Remote Sensing

利用遥感综合测量草地功能

• 批准号: RGPIN-2022-04471
• 负责人: Guo, Xulin
• 金额: $ 2.62万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754847
• 关键词: Integrating; measures; grassland; function; using

Grasslands provide vital global ecosystem services, are sensitive to disturbance and invasion, and are prone to rapid functional collapse. Grasslands worldwide have been degraded in recent decades due to intense human activity and climate change, and this degradation not only threatens ecosystems, but negatively affects ecosystem services. The pressures from degradation emphasize the need to understand, evaluate, and monitor grassland ecosystems. For decades, studies have used remote sensing tools to determine solitary measures of grassland growth and productivity, such as cover, biomass, leaf area index, canopy height, cover, structural heterogeneity, and burn and grazing effects. While this approach has advanced our understanding of how to monitor specific elements of the grassland community in isolation, a barrier to continued progress in assessing ecosystem health and its services is to integrate different elements and approaches holistically. Therefore, the long-term objective of my program is to contribute to achieving optimal and high-quality ecosystem services while maintaining sustainable grassland ecosystems. A comprehensive grassland assessment is hindered by uncertainties of understanding the expansion of unwanted species and the methods to detect and effectively assess their impacts using remote sensing and geospatial methods. Thus, I propose to focus on woody plant encroachment (WPE) and integrate this within grassland ecosystem health assessments for this proposal. WPE is a natural ecosystem process but has become a threat to grassland ecosystem health because of the effects of climate change and lack of a clear understanding of the WPE mechanisms especially in Canadian prairies, a location where WPE was not an issue in the past. There are two major challenges to understand WPE in grasslands using remote sensing and spatial techniques. First, woody plant cover is highly heterogeneous leading to mixed pixels that include various types of cover. This is because grasslands appear in various WPE stages. Second, a woody plant has typical healthy vegetation spectral features that are hard to separate from healthy productive grass species. Therefore, my five-year objectives are to 1) develop effective approaches to assess WPE in grasslands using remote sensing; 2) understand the drivers of WPE in grasslands using remote sensing, geographic information science, and spatial analytical techniques; and 3) integrate WPE into grassland ecosystem health assessment and facilitate WPE modelling. My research is devoted to understanding Canadian grassland ecosystems and I strive to keep them healthy ecologically and economically. The expected results will reveal the driving factors of WPE scholarly in the Canadian prairies, provide potential solutions for the issues, and gain new knowledge in maintaining grassland ecosystem services. This program will also provide a great opportunity for training high quality personnel.

草原提供重要的全球生态系统服务，对干扰和入侵敏感，容易迅速功能崩溃。近几十年来，由于强烈的人类活动和气候变化，世界各地的草原都在退化，这种退化不仅威胁到生态系统，而且对生态系统服务产生了负面影响。退化带来的压力强调了了解、评估和监测草原生态系统的必要性。几十年来，研究一直使用遥感工具来确定草原生长和生产力的单独衡量标准，如盖度、生物量、叶面积指数、冠层高度、盖度、结构异质性以及燃烧和放牧效应。虽然这种方法促进了我们对如何孤立地监测草原社区的具体要素的理解，但在评估生态系统健康及其服务方面继续取得进展的一个障碍是将不同的要素和方法整体地结合在一起。因此，我的计划的长期目标是在维护可持续草原生态系统的同时，为实现最佳和高质量的生态系统服务做出贡献。不确定地了解有害物种的扩展情况，以及利用遥感和地理空间方法检测和有效评估其影响的方法，阻碍了对草原的全面评估。因此，我建议将重点放在木本植物入侵(WPE)上，并将其纳入本提案的草原生态系统健康评估。WPE是一个自然生态系统过程，但由于气候变化的影响以及对WPE机制缺乏清楚了解，已成为对草原生态系统健康的威胁，特别是在加拿大大草原，在过去WPE不是一个问题。利用遥感和空间技术来理解草原上的WPE有两个主要挑战。首先，木本植物覆盖物是高度异质的，导致混合像素，包括各种类型的覆盖物。这是因为草原出现在不同的WPE阶段。其次，木本植物具有典型的健康植被光谱特征，很难从健康的多产草种中分离出来。因此，我的五年目标是：1)开发利用遥感评估草原WPE的有效方法；2)利用遥感、地理信息科学和空间分析技术了解草原WPE的驱动因素；3)将WPE整合到草原生态系统健康评估中，并促进WPE建模。我的研究致力于了解加拿大的草原生态系统，我努力保持它们在生态和经济上的健康。预期的结果将揭示加拿大草原WPE学术研究的驱动因素，为这些问题提供潜在的解决方案，并在维护草原生态系统服务方面获得新的知识。该项目也将为培养高素质人才提供很好的机会。