Articles

The Effect of Deforestation on Araceae Hemiepiphyte Populations in Toili-Bulan Track Area, Central Sulawesi

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Tropical forests are highly dynamic ecosystems that support diverse plant communities, including hemiepiphytes that depend on stable microclimatic conditions and complex forest structures. However, increasing deforestation has altered these environments, potentially affecting the survival and distribution of sensitive plant groups. This study aims to analyze the impact of deforestation on the population structure and diversity of Araceae hemiepiphytes in the Toili–Bulan track area, Central Sulawesi. The research integrates remote sensing analysis of land cover change from 2019 to 2023 with field-based vegetation surveys conducted in 2023. Land cover analysis using Sentinel-2 imagery revealed a significant decrease in forest area by 10.85%, accompanied by a substantial increase in mixed dryland agriculture (29.46%), indicating that agricultural expansion is the primary driver of deforestation. Vegetation analysis recorded 285 individuals/ha of Araceae hemiepiphytes across 13 species, with Pothos tener and Rhaphidophora species showing the highest abundance and ecological importance. The Shannon–Wiener diversity index (H’ = 2.39) indicated moderate species diversity. The findings demonstrate a strong relationship between forest degradation and hemiepiphyte populations, where reduced canopy cover and loss of mature host trees negatively affect habitat availability and microclimatic stability. Consequently, areas experiencing higher levels of deforestation exhibit lower population density and diversity of hemiepiphytic species. This study highlights the ecological sensitivity of Araceae hemiepiphytes to forest disturbance and underscores the importance of conserving forest structure to maintain biodiversity and ecosystem stability in tropical forests.

Effects of Deforestation and Anthropogenic Aspects on Streamflow in the Mau Forest Catchments in Kenya: Hydrological Modelling of Surface Water Yields from Sondu River Basin

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Climatic factors determine the amount and distribution of atmospheric water received at the land surface while the land cover conditions determine the partitioning of this water into different hydrological components and ultimately the catchment surface water yields. This study assessed the effects of deforestation of a tropical catchment on surface water yields to address fluctuating flows of the rivers emanating from Mau Forest, the largest water tower in Kenya. Sondu basin traverses Southwest Mau Forest covering an area of 3500 km2. The main channel in the basin flows in a southwest direction into Lake Victoria in an altitudinal range of 2900 to 1130 m a.s.l over a length of 173 km. Different deforestation scenarios over the basin were integrated with climate data to form inputs to a hydrologic model, Soil and Water Assessment Tool (SWAT). Using model outputs, the effects of deforestation on annual and seasonal surface water yields, represented by changes in streamflow volumes under different deforestation scenarios, were evaluated. Deforestation scenarios were derived from a supervised classification scheme of time series of LANDSAT images (1970-2020) to show deforestation trends. Effects of deforestation on the catchment water-yielding capacity were estimated as the ratio of the difference between simulated yields under different deforestation scenarios and those simulated under the pre-deforestation scenario of the 1970s decade. Results show that forest cover declined by 21% and a corresponding growth in land under agriculture by 26% in the period 1970-2020.  The decline in forest coverage resulted in an increase in the annual surface water yields of about 23% (from 152 to 187 MCM/year) throughout the period of study. This implies that there is less recharge of groundwater due to decreased infiltration and subsequent storage leading to lower flows during the dry seasons and increased flood frequencies in the basin during the wet seasons. The study has therefore, demonstrated that deforestation has reduced the stability of Mau Forest as a water tower and conservation of the forest will enhance its water-holding capacity thereby ensuring a stable water supply to rivers emanating from it as a way of combating floods and low flows in the basin. The resultant impacts on environment and society are displacements from floods and destruction of properties.