Submersed Macrophyte Vegetation and Distribution Within Lakes: Line Transect Sampling
作者:
JohnE. Titus,
期刊:
Lake and Reservoir Management
(Taylor Available online 1993)
卷期:
Volume 7,
issue 2
页码: 155-164
ISSN:1040-2381
年代: 1993
DOI:10.1080/07438149309354267
出版商: Taylor & Francis Group
关键词: aquatic plant sampling;macrophyte communities;line transects;heterogeneity;adequate sample;compositional change
数据来源: Taylor
摘要:
Line transects often provide a practical basis for quantitative, nondestructive sampling of aquatic vegetation; here four types of line transect arrangements are briefly compared: 1) transects perpendicular to the shoreline have been widely used, but may oversample nearshore areas where shorelines are convex; 2) transects parallel to each other at regular intervals may provide the best basis for mapping an area; but 3) parallel transects at (stratified) random intervals may reasonably represent different areas within the site and avoid possible biases of regular sampling. The tendency of all three methods to oversample some depth ranges and to combine data from different community types may be obviated by using 4) transects along depth contours near a given shoreline of nearly uniform exposure. Line transects may in some cases be sampled with a line intercept method, which is probably best suited for floating-leaved species, but most often a belt transect consisting of contiguous quadrats is more practical. For each sampling unit, data may be gathered on species presence or percent cover, although the former may yield more information per unit effort. Five field examples are given to illustrate sampling schemes, macrophyte community heterogeneity, and straightforward data summary procedures.
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