Figure 4 - uploaded by Noah D. Charney
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1. Ranges of Ambystoma laterale, A. jeffersonianum, and unisexuals containing hybrid nuclei of the two species. Adapted from Petranka (1998) and Bi et al. (2008).
Citations
... conductivity), microhabitat characteristics (e.g. logs), and tree species composition are known to be important drivers of species presence/abundance (Charney, 2011) and were not included in our VP scoring at local, neighbourhood, or regional levels. Recent evidence also suggests that VPs that have higher productivity have higher rates of gene flow, which would result in differences in scores at the neighbourhood and regional level (Coster et al., 2015;Murphy et al., 2010). ...
The importance of assessing spatial data at multiple scales when modeling species‐environment relationships has been highlighted by several empirical studies. However, no landscape genetics studies have optimized landscape resistance surfaces by evaluating relevant spatial predictors at multiple spatial‐scales. Here, we model multi‐scale/layer landscape resistance surfaces to estimate resistance to inferred gene flow for two vernal pool breeding salamander species, spotted (Ambystoma maculatum) and marbled (A. opacum) salamanders. Multi‐scale resistance surface models outperformed spatial layers modeled at their original spatial scale. A resistance surface with forest land cover at a 500m Gaussian kernel bandwith, and normalized vegetation index at a 100m Gaussian kernel bandwidth was the top optimized resistance surface for A. maculatum, while a resistance surface with traffic rate and topographic curvature, both at a 500m Gaussian kernel bandwidth, was the top optimized resistance surface for A. opacum. Species‐specific resistant kernels were fit at all vernal pools in our study area with the optimized multi‐scale/layer resistance surface controlling kernel spread. Vernal pools were then evaluated and scored based on surrounding upland habitat (local score) and connectivity with other vernal pools on the landscape, with resistant kernels driving vernal pool connectivity scores. As expected, vernal pools that scored highest were in areas within forested habitats and with high vernal pool densities and low species‐specific landscape resistance. Our findings highlight the success of using a novel analytical approach in a multi‐scale framework with applications beyond vernal pool amphibian conservation. This article is protected by copyright. All rights reserved.
... These included: one in Rhode Island with 151 ponds (Egan and Paton, 2008), one in suburban Boston with 105 ponds (Clark et al., 2008), one in the Quabbin Reservation in central Massachusetts with 171 ponds (D. Clark, Massachusetts Department of Conservation and Recreation, unpublished data), one in the Connecticut River Watershed in central Massachusetts with 103 ponds (Charney, 2011), and one in the Housatonic River Watershed in western Massachusetts with 366 ponds (Charney, 2011). All of these areas except the Quabbin Reservation contain a mix of many land uses including residential, industrial, forests, and fields. ...
... These included: one in Rhode Island with 151 ponds (Egan and Paton, 2008), one in suburban Boston with 105 ponds (Clark et al., 2008), one in the Quabbin Reservation in central Massachusetts with 171 ponds (D. Clark, Massachusetts Department of Conservation and Recreation, unpublished data), one in the Connecticut River Watershed in central Massachusetts with 103 ponds (Charney, 2011), and one in the Housatonic River Watershed in western Massachusetts with 366 ponds (Charney, 2011). All of these areas except the Quabbin Reservation contain a mix of many land uses including residential, industrial, forests, and fields. ...
When ecological models are used to guide conservation decisions, these models should be based upon substantial data and should be applied at appropriate spatial scales. Yet, ecologists are usually faced with scarce data and must often make subjective choices about scale. To handle limited data, the use of expert panels to parameterize models has become common. However, few studies evaluate the success of expert panels in improving models. In this study, I examine a recent resistant kernel model designed to prioritize amphibian breeding habitat for conservation. I compare the predictive ability of the model as originally parameterized by an expert panel to the predictive ability of simpler models. I optimize parameter values for spatial scale and landscape resistance using 896 ponds from 5 studies of spotted salamanders (Ambystoma maculatum) and wood frogs (Lithobates sylvaticus) in Massachusetts and Rhode Island. In predicting amphibian distributions, models examined in this study that relied upon expert-derived resistance values performed worse than null models with uninformative resistance values. The failure of the resistant kernel model offers support for the use of simple models in the face of complex ecological problems. The best scale for measuring upland habitat in these models was in the range of 1000–3000 m, an order of magnitude larger than the salamander migration scale previously proposed for wetland buffer zones.
