Abstract Title

Session S-10D: Cross-Habitat Linkages and Landscape Scale Approaches to Ecosystem Management

Keywords

Species and Food Webs

Start Date

2-5-2014 1:30 PM

End Date

2-5-2014 3:00 PM

Description

Over half of the world’s population resides in urban areas and 44% in coastal areas. As urbanization continues, the ability of coastal marine ecosystems to provide the services people want and need from them is in question. Indeed, the extent of human activity in a region often doubles as an indicator of natural ecosystem responses to multiple stressors. For instance, habitat conversion and reclamation, harvest and hunting, and human population density are frequently assumed synonymous with reductions in the abundance of wild animal populations. However, it is surprising how rarely such assumptions are actually tested against real-world observation of the relationships between stressors and components of ecosystem structure and functions. In this study we investigated how land cover, a potential indicator of stressors such as toxic contaminants, nutrient loads, and extractive uses, related to empirically measured ecosystem responses in freshwater and marine environments of Puget Sound, WA, USA. Specifically, we estimated how four aggregate ecosystem properties varied across 12 watersheds characterized by perennial streams flowing directly into Puget Sound. These properties included freshwater and marine invertebrate diversity, primary production, secondary production, and decomposition. In addition to measuring land cover, which spanned a gradient from highly rural (>80% forested) to heavily urbanized (>80% developed), we also tracked other factors such as water temperature, salinity, stream flow, and nutrient loads. Surprisingly, aggregate properties of freshwater and marine ecosystems did not differ in a systematic way across the urban gradient. These preliminary results provide a contrast to prevailing wisdom that urban ecosystems differ dramatically from pristine ones, and suggest that land cover indicators may not always provide useful information about changes in aquatic and marine ecosystems. Because ecosystem responses can be idiosyncratic, though, this study also highlights the importance of groundtruthing stressor-ecosystem relationships to ensure that indicators are indeed meaningful.

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May 2nd, 1:30 PM May 2nd, 3:00 PM

How Much City is Too Much City? Diversity and Ecosystem Functions Along an Urban Gradient in Puget Sound

Room 611-612

Over half of the world’s population resides in urban areas and 44% in coastal areas. As urbanization continues, the ability of coastal marine ecosystems to provide the services people want and need from them is in question. Indeed, the extent of human activity in a region often doubles as an indicator of natural ecosystem responses to multiple stressors. For instance, habitat conversion and reclamation, harvest and hunting, and human population density are frequently assumed synonymous with reductions in the abundance of wild animal populations. However, it is surprising how rarely such assumptions are actually tested against real-world observation of the relationships between stressors and components of ecosystem structure and functions. In this study we investigated how land cover, a potential indicator of stressors such as toxic contaminants, nutrient loads, and extractive uses, related to empirically measured ecosystem responses in freshwater and marine environments of Puget Sound, WA, USA. Specifically, we estimated how four aggregate ecosystem properties varied across 12 watersheds characterized by perennial streams flowing directly into Puget Sound. These properties included freshwater and marine invertebrate diversity, primary production, secondary production, and decomposition. In addition to measuring land cover, which spanned a gradient from highly rural (>80% forested) to heavily urbanized (>80% developed), we also tracked other factors such as water temperature, salinity, stream flow, and nutrient loads. Surprisingly, aggregate properties of freshwater and marine ecosystems did not differ in a systematic way across the urban gradient. These preliminary results provide a contrast to prevailing wisdom that urban ecosystems differ dramatically from pristine ones, and suggest that land cover indicators may not always provide useful information about changes in aquatic and marine ecosystems. Because ecosystem responses can be idiosyncratic, though, this study also highlights the importance of groundtruthing stressor-ecosystem relationships to ensure that indicators are indeed meaningful.