Keanekaragaman Vegetasi dan Cadangan Karbon pada Sistem Agroforestri Kebun Bangelan, Jawa Timur

Abstract

PTPN I Regional 5 Bangelan Plantation is located in Bangelan Village, specifically in Wonosari District, Malang Regency, East Java. The total concession area of the Bangelan Plantation spans 883.20 hectares, consisting of two plantation divisions: Afdeling Besaran and Afdeling Kampung Baru. Due to climate change, the Bangelan Plantation is facing a decline in coffee production. The causes of this decline include disruptions in the flowering system due to unpredictable climate changes, pest infestations affecting coffee plants, and weed invasion that absorbs nutrients, leading to competition between the main coffee plants and weeds. The objectives of this research were to analyze vegetation diversity within coffee agroforestry systems and estimate carbon stocks across different agroforestry patterns. The method used in this study was purposive sampling, based on representative agroforestry stands. A total of 27 plots were established, each measuring 20 m x 20 m. These plots were distributed across three plots per planting year, covering a total area of 1.08 ha. The dominant combination in the agroforestry system implemented by Kebun Bangelan in this study is a mix of sengon, jabon, lamtoro, and robusta coffee plants. One of the purposes of this planting pattern is to regulate the intensity of incoming sunlight, referred to by the Bangelan management as the "star sprinkle" method. The dominant species for all classes of seedlings, poles, saplings, and trees are Leucaena leucocephala and Coffea robusta. An average carbon stock is 21.86 tons, and a total carbon stock is 196.74 tons. The highest total carbon stock is 29,24 ton, which is found in the planting 1935 year. Agroforestry patterns integrating diverse shade species with moderate canopy density proved to be the most effective in supporting biodiversity and enhancing carbon sequestration.