Degradation of Riparian Tree Diversity on Spring Fed Drains and Its Impacts to Water Quality, East Java

The research aimed at examining the impacts of degradation of riparian tree diversity toward water quality from some springs to their drains in East Java, Indonesia. This descriptive study was conducted in selected springs and their drains in Jember, Kediri, Pasuruan, and Malang from April 2012 to January 2013. Spring water of Meru Betiri National Park was chosen as a reference site. The quality of riparian tree diversity and the water was sampled on three replications. Data were tabulated by statistical analyses using cluster and Spearman correlation. The result showed that there were 69 species belonging to 28 families of riparian tree were found in the springs and their drains. Moraceae was found to be the key family of natural riparian trees, and native trees, except in Kediri, inhabited almost all springs and their drains (92.75 %). All the observed springs were degrading, compared to the natural one in Meru Betiri National Park where trees grew in strata A to E and showed the highest diversity index (H’=3.2). All springs were found to have high quality of water, but the water in their downstream became so turbid, depending on the quality of riparian tree diversity grown around the springs. The quality of riparian diversity was strongly influenced by land use and human activities such as illegal logging, intensive agriculture, and settlement. There was a positive correlation between riparian tree diversity and water transparency and color; yet, there was a negative correlation with pH of the water. Low pH, high water transparency and colorless water were found in stations where we found rich tree species, high diversity index, wide and stratified riparian trees.