Estimating Climate Resilience for Conservation across Geophysical Settings

Abstract

Conservationists need methods to conserve biological diversity while allowing species and communities to rearrange in response to a changing climate. We developed and tested such a method for northeastern North America that we based on physical features associated with ecological diversity and site resilience to climate change. We comprehensively mapped 30 distinct geophysical settings based on geology and elevation. Within each geophysical setting, we identified sites that were both connected by natural cover and that had relatively more microclimates indicated by diverse topography and elevation gradients. We did this by scoring every 405 ha hexagon in the region for these two characteristics and selecting those that scored >SD 0.5 above the mean combined score for each setting. We hypothesized that these high-scoring sites had the greatest resilience to climate change, and we compared them with sites selected by The Nature Conservancy for their high-quality rare species populations and natural community occurrences. High-scoring sites captured significantly more of the biodiversity sites than expected by chance (p < 0.0001): 75% of the 414 target species, 49% of the 4592 target species locations, and 53% of the 2170 target community locations. Calcareous bedrock, coarse sand, and fine silt settings scored markedly lower for estimated resilience and had low levels of permanent land protection (average 7%). Because our method identifies—for every geophysical setting—sites that are the most likely to retain species and functions longer under a changing climate, it reveals natural strongholds for future conservation that would also capture substantial existing biodiversity and correct the bias in current secured lands.Identificación de Sitios Duraderos para la Conservación Usando la Diversidad del Paisaje y las Conexiones Locales para Estimar la Capacidad de Recuperación al Cambio ClimáticoResumenLos conservacionistas necesitan un método mediante el cual poder conservar la diversidad biológica mientras permiten que las especies y las comunidades se reorganicen con respecto al clima cambiante. Desarrollamos y probamos tal método, el cual basamos en características físicas asociadas con la diversidad ecológica y la capacidad de recuperación del sitio con respecto al cambio climático, en el noreste de Norteamérica. Mapeamos comprensivamente 30 escenarios geofísicos distintos basados en la geología y la elevación. Dentro de cada escenario geofísico identificamos sitios que estaban conectados por una cubierta natural y que tenían relativamente más microclimas indicados por la topografía diversa y los gradientes de elevación. Hicimos esto al puntuar cada hexágono de 450 ha en la región con estas dos características y al seleccionar aquellos que tuvieron una puntuación >SD 0.5 por encima del puntaje combinado promedio para cada escenario. Nuestra hipótesis fue que estos sitios con altas puntuaciones tuvieron la mayor capacidad de recuperación. Los comparamos con los sitios seleccionados por The Nature Conservancy por sus...

A landscape index of ecological integrity to inform landscape conservation

“…We developed an approach that has been used in several real-world applications (see below) that is distinctive in several ways. 465 First, our approach is based predominantly on geophysical settings (i.e., the geophysical stage) similar to approaches proposed by others (e.g., Anderson and Ferree 2010, Anderson et al 2014, Beier et al 2015, but modified to make limited use of the dominant biotic community as well. Specifically, we include the dominant potential life form of the vegetation in the broad suite of ecological settings variables that are used to define the biophysical setting of each cell, 470 which affects ecological similarity and resistance as incorporated into a few of the ecological integrity metrics.…”

“…Ecological neighborhoods (sensu Addicott et al 1987) play an important role in the computation of the ecological integrity metrics described below, as in other approaches (e.g., Theobold 2013, Anderson et al 2014), but our particular implementation of neighborhoods are distinctive of our 145 approach. We use non-linear kernels to specify how to weight the ecological neighborhood of a focal cell; i.e., to determine how much influence a neighboring cell has on the integrity of the focal cell.…”

“…This measure of site resiliency is agnostic to the distribution of biota and explicit climate change projections, but 75 is somewhat sensitive to the impacts of human development via the fragmentation of natural areas. This approach has been shown to perform well as a surrogate for species diversity (Anderson et al 2014).…”

“…One approach has been to focus solely on the 65 geophysical environment without attention to the biota, and identify and prioritize representative, diverse and connected geophysical settings based on one or more metrics (e.g., Anderson et al 2014;Beier et al 2015). Here the goal is to conserve the abiotic stage and allow the biota to change and "play out" on this stage over time, especially in response to climate change (Beier and Brost 2010;Beier 2012).…”

“…Here the goal is to conserve the abiotic stage and allow the biota to change and "play out" on this stage over time, especially in response to climate change (Beier and Brost 2010;Beier 2012). For example, Anderson et al (2014) measured site resiliency using 70 a combination of two metrics: 1) landscape diversity, which refers to the number of microhabitats and climatic gradients available within a given area based on the variety of landforms, elevation range, soil diversity, and wetland extent and density, and 2) local connectedness, which refers to the accessibility of neighboring natural areas. This measure of site resiliency is agnostic to the distribution of biota and explicit climate change projections, but 75 is somewhat sensitive to the impacts of human development via the fragmentation of natural areas.…”