Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California

abstract: Species distribution modeling is used to study changes in biodiversity and species range shifts, two currently well-known manifestations of climate change. The focus of this study is to explore how distributions of suitable habitat might shift under climate change for shrub communities wit...

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Other Authors: James, Jennifer (Author)
Format: Dissertation
Language:English
Published: 2014
Subjects:
Online Access:http://hdl.handle.net/2286/R.I.24761
id ndltd-asu.edu-item-24761
record_format oai_dc
spelling ndltd-asu.edu-item-247612018-06-22T03:04:45Z Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California abstract: Species distribution modeling is used to study changes in biodiversity and species range shifts, two currently well-known manifestations of climate change. The focus of this study is to explore how distributions of suitable habitat might shift under climate change for shrub communities within the Santa Monica Mountains National Recreation Area (SMMNRA), through a comparison of community level to individual species level distribution modeling. Species level modeling is more commonly utilized, in part because community level modeling requires detailed community composition data that are not always available. However, community level modeling may better detect patterns in biodiversity. To examine the projected impact on suitable habitat in the study area, I used the MaxEnt modeling algorithm to create and evaluate species distribution models with presence only data for two future climate models at community and individual species levels. I contrasted the outcomes as a method to describe uncertainty in projected models. To derive a range of sensitivity outcomes I extracted probability frequency distributions for suitable habitat from raster grids for communities modeled directly as species groups and contrasted those with communities assembled from intersected individual species models. The intersected species models were more sensitive to climate change relative to the grouped community models. Suitable habitat in SMMNRA's bounds was projected to decline from about 30-90% for the intersected models and about 20-80% for the grouped models from its current state. Models generally captured floristic distinction between community types as drought tolerance. Overall the impact on drought tolerant communities, growing in hotter, drier habitat such as Coastal Sage Scrub, was predicted to be less than on communities growing in cooler, moister more interior habitat, such as some chaparral types. Of the two future climate change models, the wetter model projected less impact for most communities. These results help define risk exposure for communities and species in this conservation area and could be used by managers to focus vegetation monitoring tasks to detect early response to climate change. Increasingly hot and dry conditions could motivate opportunistic restoration projects for Coastal Sage Scrub, a threatened vegetation type in Southern California. Dissertation/Thesis James, Jennifer (Author) Franklin, Janet (Advisor) Rey, Sergio (Committee member) Wentz, Elizabeth (Committee member) Arizona State University (Publisher) Climate change Conservation biology Natural resource management California Chaparral Climate Change Coastal MaxEnt eng 98 pages M.A. Geography 2014 Masters Thesis http://hdl.handle.net/2286/R.I.24761 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2014
collection NDLTD
language English
format Dissertation
sources NDLTD
topic Climate change
Conservation biology
Natural resource management
California
Chaparral
Climate Change
Coastal
MaxEnt
spellingShingle Climate change
Conservation biology
Natural resource management
California
Chaparral
Climate Change
Coastal
MaxEnt
Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California
description abstract: Species distribution modeling is used to study changes in biodiversity and species range shifts, two currently well-known manifestations of climate change. The focus of this study is to explore how distributions of suitable habitat might shift under climate change for shrub communities within the Santa Monica Mountains National Recreation Area (SMMNRA), through a comparison of community level to individual species level distribution modeling. Species level modeling is more commonly utilized, in part because community level modeling requires detailed community composition data that are not always available. However, community level modeling may better detect patterns in biodiversity. To examine the projected impact on suitable habitat in the study area, I used the MaxEnt modeling algorithm to create and evaluate species distribution models with presence only data for two future climate models at community and individual species levels. I contrasted the outcomes as a method to describe uncertainty in projected models. To derive a range of sensitivity outcomes I extracted probability frequency distributions for suitable habitat from raster grids for communities modeled directly as species groups and contrasted those with communities assembled from intersected individual species models. The intersected species models were more sensitive to climate change relative to the grouped community models. Suitable habitat in SMMNRA's bounds was projected to decline from about 30-90% for the intersected models and about 20-80% for the grouped models from its current state. Models generally captured floristic distinction between community types as drought tolerance. Overall the impact on drought tolerant communities, growing in hotter, drier habitat such as Coastal Sage Scrub, was predicted to be less than on communities growing in cooler, moister more interior habitat, such as some chaparral types. Of the two future climate change models, the wetter model projected less impact for most communities. These results help define risk exposure for communities and species in this conservation area and could be used by managers to focus vegetation monitoring tasks to detect early response to climate change. Increasingly hot and dry conditions could motivate opportunistic restoration projects for Coastal Sage Scrub, a threatened vegetation type in Southern California. === Dissertation/Thesis === M.A. Geography 2014
author2 James, Jennifer (Author)
author_facet James, Jennifer (Author)
title Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California
title_short Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California
title_full Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California
title_fullStr Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California
title_full_unstemmed Modeling Suitable Habitat Under Climate Change for Chaparral Shrub Communities in the Santa Monica Mountains National Recreation Area, California
title_sort modeling suitable habitat under climate change for chaparral shrub communities in the santa monica mountains national recreation area, california
publishDate 2014
url http://hdl.handle.net/2286/R.I.24761
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