Applying a hydrogeomorphic channel classification to understand spatial patterns in riparian vegetation

Abstract

Questions Hydrogeomorphic channel classifications are widely employed to understand natural phenomena in Earth sciences, but are rarely used in riparian vegetation studies. However, when these types of classifications correspond to physical process domains (discrete landscape units with consistent abiotic attributes), they may be useful in distinguishing habitat and vegetation types. We assessed the ecological significance of a hydrogeomorphic stream channel classification by addressing the following questions: (1) does perennial plant community composition differ among hydrogeomorphic channel types; (2) which species and functional groups contribute to compositional variation among channel types in the Sonoran Desert; and (3) what are the stream reach‐scale geomorphic drivers of compositional variation? Location Sonoran Desert, Arizona, USA. Methods We compared perennial riparian plant community composition among five a priori hydrogeomorphic channel types at 86 stream reaches in arid ephemeral watersheds. Floristic differences among channel types were assessed using PERMANOVA. GLM were used to identify species and functional groups whose abundance differed among channel types. Abiotic drivers of compositional differences were identified through correlations among biotic and abiotic matrices. Results Community composition differed significantly among channel types, with distinctive vegetation in bedrock, piedmont headwater and braided channels. While different from other channel types, vegetation in bedrock with alluvium and incised alluvium channels was broadly similar, but could be distinguished by the abundance of common species and functional groups. The density of drought‐deciduous subshrubs, as well as large woody plants with evergreen, drought‐deciduous and photosynthetic stem phenology contributed to the observed compositional variance. Bed slope was the primary driver of compositional differences among channel types, with elevation providing additional explanatory power. Conclusions Hydrogeomorphic channel classifications corresponding to distinctive fluvial process domains are useful for understanding spatial variability in riparian habitats and resulting differences in plant community composition in the Sonoran Desert. Analogous spatial patterns of riparian plant communities previously reported from other arid regions suggest that these general channel types are broadly applicable.

Beyond the light effect: How hydrologic and geomorphologic stream features control microbial distribution across pool sequences in a temperate headwater stream

“…Our results are in alignment with other studies of riparian vegetation influence on stream channel geomorphic characteristics (Hupp, 1992; Shaw et al, 2018; Tabacchi et al, 1998), as well as shading and stream water temperature regime (Sweeney & Newbold, 2014). Temperature variations and organic content, two parameters with strong correlations to our observed community variations, fluctuate predictably along the riparian gradient due to changes in canopy cover and channel geomorphology.…”

Application of UAV-Based Multi-angle Hyperspectral Remote Sensing in Fine Vegetation Classification

“…The use of remote sensing technology has become the main approach for vegetation ecological resource surveys and environmental monitoring due to the corresponding real-time, repeatability, and wide-coverage advantages [2][3][4]. With the development of remote sensing technology, visible light, multispectral, hyperspectral, and other sensors have been widely used in the remote sensing of vegetation [5,6], and more hyperspectral and high-resolution information has been obtained than ever before, greatly improving the accuracy of image classification [7,8].…”

Differences in physical habitat simulation system modelling results using benthic or pelagic fish species as indicators in Peruvian Andes–Amazon rivers

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