RAPID: Hurricane Maria: ASSESSING LANDSCAPE RESILIENCE TO A CHANGING DISTURBANCE REGIME

飓风的强度预计会随着气温的上升而上升，个别风暴可能会对森林中的碳动态产生重大影响。一场强大的飓风可以将大量活的森林碳转化为死亡的生物质，其中大部分碳将通过自然分解和土壤碳损失返回大气。这是对气候变暖的积极反馈。严重的风暴还会改变物种组成，使森林容易受到随后的飓风的影响。然而，大多数关于飓风对生态系统的影响的研究都是在地块一级进行的，而且是在有限的环境条件下进行的。因此，我们对影响森林在飓风面前的脆弱性和风灾后恢复的因素在景观层面上的了解极其有限。这项研究将结合遥感卫星产品、田间地块数据和数学模型，调查飓风玛丽亚对波多黎各森林景观的影响。拟议的研究将产生制定适应气候变化和变化的森林管理做法所必需的数据和知识。数据将公开提供，并与政府机构共享。一名技术人员、一名研究生和十名野外志愿者将接受生态研究方面的培训。需要作出快速反应，以防止因植被分解而造成的数据损失，并将遥感数据与地面损害观测联系起来。飓风是北大西洋沿海地区温带和热带森林的主要自然干扰因素。严重的风暴还有利于早期演替树种的补充，这些树种特别容易受到随后的飓风的影响，这是一个积极的反馈，加剧了生态系统的脆弱性。风灾在整个景观中的空间分布取决于风暴气象、自然景观异质性以及单株树木和集合林结构的属性。要弄清这些因素对观测到的损害的贡献可能很困难，因为树种对风暴破坏的脆弱性不同，同时，相对于景观因素，树种的分布是非随机的。要了解生态系统对大范围强风暴的脆弱性，需要能够梳理出景观和当地因素的贡献的方法。拟议的研究将依靠遥感工具的最新进展，包括光学和高光谱图像以及光探测和测距，以对导致风暴影响在广泛空间范围内的空间异质性的景观和当地因素产生新的见解。研究人员将解决以下问题：1)地形、坡度、坡向、地质、森林年龄和破碎化等景观特征如何影响强飓风后的风害和生物量损失；2)飓风破坏对森林组成的选择性压力是什么；以及(3)景观异质性如何影响生物量恢复？

The intensity of hurricanes is anticipated to rise with rising temperatures and individual storms can have dramatic impacts on the carbon dynamics in forests. A strong, single hurricane can convert significant amounts of living forest carbon into dead biomass, and much of that carbon will return to the atmosphere through natural decomposition and soil carbon losses. This acts as a positive feedback to a warming climate. Severe storms also change species composition making the forest vulnerable to subsequent hurricanes. The majority of studies on impacts of hurricanes on ecosystems, however, have been conducted at the plot level and over a limited range of environmental conditions. As a result, our understanding of the factors that impact forest vulnerability to hurricanes and post-storm recovery at the landscape scale is extremely limited. This research will investigate the effects of Hurricane Maria on forested landscapes in Puerto Rico using a combination of a remotely sensed satellite products, data from field plots, and mathematical models. The proposed research will generate data and knowledge essential for the development of forest management practices that are resilient to climate variability and change. Data will be made publicly available and shared with government agencies. One technician, one graduate student, and ten field volunteers will be trained in ecological research. A RAPID response is required to prevent loss of data due to vegetation decomposition and to link remote sensing data to ground observations of damage. Re-growth after storms is swift; the remote sensing signal lasts approximately 1 year following a storm, until post-storm recovery generates new leaf biomass.Hurricanes represent the dominant natural disturbance in temperate and tropical forests in coastal regions of the North Atlantic. Severe storms also favor recruitment of early successional tree species that are particularly vulnerable to subsequent hurricanes, acting as a positive feedback that exacerbates ecosystem vulnerability. The spatial distribution of wind damage across the landscape depends on storm meteorology, physical landscape heterogeneity, and the attributes of individual trees and aggregate stand structure. Disentangling the contribution of each of these factors to observed damage can be difficult because tree species differ in their vulnerability to storm damage and, at the same time, are distributed in a non-random fashion with respect to landscape factors. Understanding ecosystem vulnerability to severe storms over large spatial extents requires approaches that can tease apart the contributions of landscape and local factors. The proposed research will rely on recent advances in remote sensing tools including optical and hyperspectral images and Light Detection and Ranging to generate novel insights into the landscape and local factors that lead to spatial heterogeneity in storm impacts across broad spatial extents. Investigators will address the following questions: 1) how do landscape characteristics such as topography, slope, aspect, geology, and forest age and fragmentation influence wind damage and biomass loss after a severe hurricane; 2) what is the selective pressure of hurricane damage on forest composition; and (3) how does landscape heterogeneity influence biomass recovery?