TY - BOOK AU - Bhawane Akash Kailas AU - Gopakumar S (Guide) TI - Influence of vegetation on the hydrologic characteristics of Irumbupalam and Mayiladumpara watersheds in Peechi - Vazhani wildlife sanctuary, Thrissur, Kerala U1 - 634.9 PY - 2022/// CY - Vellanikkara PB - Department of Natural Resource Management, College of Forestry KW - Natural Resource Management N1 - MSc N2 - Forest vegetation and water are two valuable resources for mankind, and both the resources influence each other. It is important to understand the interrelationship between forest vegetation and hydrology. The present study was undertaken in Irumbupalam and Mayiladumpara watersheds in Peechi-Vazhani wildlife sanctuary, Thrissur, Kerala. The aim of the study was to identify and quantify the hydrological differences between these watersheds and assess the extent to which these differences are related to vegetation characteristics. Mayiladumpara watershed comprised of eight different land use classes of which mixed crops and trees accounts highest (27.91%) area whereas Irumbupalam comprised of three land use classes, of which, reserved forest occupied the highest (67.74%) of area. Within each watershed, twenty-two, 10 m x 10 m sample plots were laid out for detailed enumeration of vegetation and soil parameters. The Irumbupalam harbored a greater number of tree species (38) compared to the Mayiladumpara (28). The mean tree density ha-1 was higher in Mayiladumpara (586 individuals ha-1 ) compared to Irumbupalam (509 individuals ha-1 ). Similarly, the mean tree basal area was greater in Mayiladumpara (45.48 m2 ha-1 ) as compared to Irumbupalam (13.97 m2 ha-1 ). The tree diversity was found to be maximum in Irumbupalam watershed. Physico- chemical properties of soil viz. soil pH, organic carbon, water holding capacity, soil moisture and soil porosity showed showed higher values for Irumbupalam watershed. There were differences in terms of soil physico- chemical properties in watersheds between pre-monsoon and monsoon season. The highest values for soil pH (5.87-7.05), C (2.12-6.61%), porosity (41.42-44.95 %), WHC (41.85-72.92 %), SM (9.2- 44.07 %) was recorded in Irumbupalam. Whereas, BD (0.74-1.64 gm cm-3) values were higher in Mayiladumpara than Irumbupalam. Canonical correspondence analysis (CCA) showed a complex interrelationship amongst species clustering, site and soil properties. 118 Mean annual precipitation for both watersheds were recorded. Stream flow measurements were taken monthly for stream depth and stream velocity using float method. Groundwater levels observations was taken monthly from selected wells. Water quality parameter was assessed monthly from upstream, mid-stream and downstream points for both watersheds. Mean rainfall for Irumbupalam and Mayiladumpara for the period (2017-21) was 457 mm and 514.8 mm respectively in the pre-monsoon season, and 1555.5 mm and 1567.7 mm in the monsoon season. Mayiladumpara's monthly streamflow was always higher than Irumbupalam. The pre-monsoon water yield of well was higher in Irumbupalam as compared to Mayiladumpara. The Irumbupalam watershed always had a higher water table than the Mayiladumpara watershed. Stream water temperature (WT), total dissolved solids (TDS), electrical conductivity (EC), turbidity, nitrate (NO3- ) were significantly (p<0.05) higher in Mayiladumpara Irumbupalam. In contrast, dissolved oxygen (DO) and pH of water was significantly higher (p<0.05) in the Irumbupalam. Seasonal variation was observed in the physico-chemical properties of stream water both in watersheds over the study period of eight months. Pearson correlation coefficient revealed that canopy closure was significantly related to some hydrological parameters. Canopy closure was significantly correlated with four water physico-chemical parameters (p<0.05) viz., dissolved oxygen (DO), temperature, electrical conductivity (EC), (NO3-). This indicated that canopy closure is related to water quality. Canopy cover was positively correlated (p<0.05) with DO and negatively correlated with nitrate (NO3- ) (p<0.05). Quantitative as well as qualitative hydrological differences was observed between these watersheds. The physico-chemical parameters of stream water like Dissolved oxygen, Electrical conductivity, Water temperature, Nitrate was found to be influenced by canopy closure of watersheds. The Canopy closure was significantly and positively correlated with soil water holding capacity, soil moisture and soil organic carbon. Soil water holding capacity was found to be significantly and positively correlated with soil porosity, soil moisture soil organic carbon and negatively correlated with soil bulk density. 119 Soil porosity was positively correlated with soil moisture and soil organic carbon and negatively correlated with soil bulk density. Soil moisture was positively correlated with the soil organic carbon and negatively with soil bulk density. Soil bulk density was negatively correlated with the soil organic carbon More extensive study covering a range of added parameters should be conducted to understand the function of different forest ecosystems in maintaining hydrological processes. The hydrological characteristics should be researched for two or more annual cycles to get a comprehensive understanding. The results of this study also point to an imperative necessity of longer duration studies covering (premonsoon, monsoon, and post-monsoon) seasons for more complete view of the hydrological functions of a forest watershed ER -