Skip to Main Content
Spatial relationships in a dendritic network: the herpetofaunal metacommunity of the Mattole River catchment of northwest California.Author(s): Hartwell Welsh; Garth Hodgson
Source: Ecography 34: 49-66
Publication Series: Scientific Journal (JRNL)
Station: Pacific Southwest Research Station
Download Publication (262.64 KB)
DescriptionWe investigated the aquatic and riparian herpetofauna in a 789 km² river catchment in northwest California to examine competing theories of biotic community structuring in catchment stream networks. Research in fluvial geomorphology has resulted in multi-scale models of dynamic processes that cyclically create, maintain, and destroy environments in stream networks of mountain catchments. These models have been applied to understanding distributions of invertebrates, algae, fishes and their habitats across entire basin networks, but similar approaches with herpetofauna are rare. We examined multi-scale spatial patterns of multiple species as they related to variation in channel types, channel settings, and within-channel attributes that result from these processes. From 83 reaches distributed randomly throughout the watershed, we distinguished four channel types: 1) high gradient with step pool/cascade structures; 2) 2-4% gradient with structure controlled by moderately steep valleys; 3) slightly entrenched, lower gradient, meandering with riffle/pool structure; and 4) and low gradient, shallow, unconfined, multiple or migrating in broad alluvial valleys. The composition of herpetofauna differed in five of six pair-wise comparisons among these channel types, indicating a minimum of three distinct mesoscale assemblages. We used non-parametric multiple regression (NPMR) to examine relationships at multiple spatial scales. NPMR revealed species-specific associations with channel settings and within-channel environments among species sharing the same sets of channel types. Morphological adaptations, biophysical limits and natural histories of each species best explained their associations with distinct sets of attributes surrounding and within channel types. While each set of species has similarly adapted to fluvial and geomorphic disturbance processes structuring channels at the mesoscale, species within each set have adapted to a unique set of attributes that are best discerned when their spatial relationships are examined across multiple spatial scales. We evaluated the various spatial patterns against hypotheses of stream community organization and metacommunity perspectives.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationWelsh, H. H., Jr.; and Hodgson, G. R. 2010. Spatial relationships in a dendritic network: the herpetofaunal metacommunity of the Mattole River catchment of northwest California. Ecography 34: 49-66.
- Carbon pools along headwater streams with differing valley geometry in Rocky Mountain National Park, Colorado (Abstract)
- Faunal assemblages and multi-scale habitat patterns in headwater tributaries of the South Fork Trinity River - an unregulated river embedded within a multiple-use landscape
- Hyporheic exchange in mountain rivers II: Effects of channel morphology on mechanics, scales, and rates of exchange
XML: View XML