KEANEKARAGAMAN DAN KELIMPAHAN VEGETASI RIPARIAN DI HULU DAN TENGAH SUNGAI GAJAH WONG YOGYAKARTA

Riparian vegetation is community of plants that can grow along the right side and left side of the river. The region of Gajah Wong riverside is a prone land disruption caused by natural phenomena or human utilization. This diruption can result in reduced diversity and abundance of riparian vegetation. The purpose of this research is to study the diversity and abundance of riparian vegetation and the environment factors that influence. The research was done from January to March 2016 using the belt transect method laid purposively, with a plot size of 5 x 20 meters, as much as 10 plots in each location in headwaters and middle of the river. The data were analysed using Canonical Corespondence Analysis (CCA). The result showed there were 55 species consisting of 28 families. Three families that were most found in both locations are Asteraceae (16%), Poaceae (14%) and Araceae (9%). Diversity index (H’) in both locations were classified medium (headwaters: 1.90; middle: 1.26). CCA analysis result showed that environment factors influenced the diversity and abundance of tree, sampling and seedling were soil pH, soil moisture, amount-N, C-organic and light intensity. Environment factor that influenced diversity and abundance of vegetation shrubs, herbs and grasses were soil moisture, amount-N, C-organic, light intensity, K-availability, P2O5, soil pH, soil temperature and air temperature