A reservoir landscape for age-0 largemouth bass

Landscape ecology is concerned with how ecological processes are affected by spatial patterns. Identification of heterogeneity in littoral zones has expanded the conceptual framework of aquatic landscapes. Long-term study of a reservoir largemouth bass population indicated that the amount and arrangement of habitat regulated the population processes. The distribution of age-0 largemouth bass was quantified in relation to littoral habitat and relations between landscape features and population parameters on scales from embayment to microhabitat were determined. At the embayment scale, shoreline slope and amount of gravel substratum predicted fivefold variability in abundance among four reservoir embayments. Within an embayment, these habitat features explained between 37 and 88 percent of variation in shoreline distribution of age-0 largemouth bass. At the microhabitat scale, age-0 largemouth bass exhibited patchy distributions in relation to gravel substratum at 40 percent of sites. These results indicate that the landscape scale domain for young largemouth bass is large; whereas, specific patterns explained processes across multiple scales. Distributions of age-0 largemouth bass in relation to habitat, however, were apparent on a fine scale (10 m) and these data, coupled with limited movement behavior of young largemouth bass, indicate that the ecological neighborhood of this life stage is small. Our data also suggested that some habitats may be source habitats because embayments with hypothesized higher source/sink ratios were more productive. Although patch arrangement critical to young largemouth bass ecology was not quantified, it was apparent that embayments with more complex habitats likely provided the extent of the landscape for age-0 largemouth bass in Jordan Lake. Identification of scale of patchiness (of fish distributions and habitats) for this life stage will assist in making inferences regarding complex ecological processes that can affect year-class productivity on multiple scales. ?? 2002 by the American Fisheries Society.