Abstract:

Aims Riparian zones encompass sharp environmental gradients with an unusually diverse array of landforms, habitats and communities. The land cover pattern of the riparian zone was studied in the upper Minjiang River, China, to determine: 1) the land cover pattern and 2) environmental factors affecting the pattern.

Methods Sixty-eight quadrats with 12 classes of land cover were sampled along the main stream of the river. Based on the spatial information and environmental factors, the pattern of land cover was investigated using two-way indicator species analysis (TWINSPAN) and detrended canonical correspondence analysis (DCCA).

Important findings Land cover was classified into high, moderate and low/non-vegetation types. These had different distributions, with the moderate type most predominant. The quadrats were classified into 8 groups, within which each quadrat had similar land cover. Based on land cover, the riparian zone could be divided into three parts: the upper part with mostly high vegetation types, the middle part, which occupied the greatest area, mostly with moderate vegetation types, and the lower part, mostly with the man-made land cover type. Temperature and elevation were the most important environmental factors related to the land cover pattern, followed by precipitation and human distribution. From upper to lower parts of the riparian zone, temperature, precipitation and human activity increase. The overall result is explicitly different land cover patterns in the three parts of the riparian zone. The pattern of dry valley is controlled by the interaction of water and temperature. Ordination was useful in interpreting the land cover pattern of the riparian zone in the upper Minjiang River. Environment factors had a larger effect on this pattern than human factors.

Key words: riparian zone, TWINSPAN, DCCA, land cover, the upper Minjiang River