Electronic Theses and Dissertation

Hutan memiliki peran penting dalam menjaga keseimbangan ekosistem melalui keanekaragaman hayati, penyimpanan karbon, konservasi tanah, serta pengaturan iklim mikro. salah satu bentuk pengelolaan lahan yang mampu mempertahankan fungsi ekologis sekaligus memberikan manfaat ekonomi bagi masyarakat adalah sistem agroforestri kopi. di kecamatan ketol, kabupaten aceh tengah, sebagian besar kebun kopi dikelola dalam skema perhutanan sosial oleh kelompok tani hutan (kth). namun, informasi mengenai struktur dan komposisi vegetasi pada sistem agroforestri tersebut masih terbatas sehingga diperlukan kajian yang mampu menggambarkan kondisi vegetasi secara kuantitatif. penelitian ini bertujuan menganalisis struktur dan komposisi vegetasi berdasarkan tingkat kerapatan vegetasi menggunakan normalized difference vegetation index (ndvi) sebagai dasar stratifikasi, sehingga hasil penelitian dapat menjadi acuan dalam pengelolaan agroforestri kopi yang berkelanjutan dan berbasis data ilmiah. penelitian dilaksanakan pada november–desember 2025 di tiga kelompok tani hutan, yaitu desa bintang pepara, desa kekuyang dan desa bah, kecamatan ketol, kabupaten aceh tengah. pengambilan sampel menggunakan metode purposive sampling berdasarkan kelas kerapatan vegetasi hasil klasifikasi ndvi. data vegetasi dikumpulkan melalui inventarisasi lapangan pada tingkat semai, pancang, tiang dan pohon, kemudian dianalisis menggunakan indeks nilai penting (inp), indeks keanekaragaman shannon wiener (h'), indeks kemerataan (e), serta indeks kekayaan jenis margalef (dmg). hasil penelitian menunjukkan bahwa sistem agroforestri kopi di ketiga lokasi memiliki struktur vegetasi berlapis yang terdiri atas tingkat semai, pancang, tiang dan pohon, dengan komposisi vegetasi yang didominasi oleh kopi (coffea arabica) sebagai tanaman utama serta beberapa pohon penaung seperti alpukat (persea americana), lamtoro (leucaena leucocephala), gamal (gliricidia sepium), durian (durio zibethinus), kemiri (aleurites moluccanus), dan kayu manis (cinnamomum verum). desa bintang pepara memiliki jumlah individu vegetasi tertinggi sebanyak 230 individu, desa bah sebanyak 209 individu, sedangkan desa kekuyang memiliki 48 individu. analisis struktur vegetasi menunjukkan bahwa desa bah memiliki penutupan tajuk yang relatif lebih rapat, desa bintang pepara memiliki distribusi vegetasi yang cukup merata, sedangkan desa kekuyang menunjukkan struktur tajuk yang lebih terbuka. nilai keanekaragaman, kemerataan, dan kekayaan jenis pada ketiga lokasi umumnya berada pada kategori rendah hingga sedang, yang menunjukkan adanya dominasi beberapa spesies utama, terutama kopi dan jenis pohon penaung tertentu. hasil ini mengindikasikan bahwa sistem agroforestri kopi di kawasan perhutanan sosial kecamatan ketol masih mampu mempertahankan fungsi ekologis melalui keberadaan struktur vegetasi bertingkat, namun diperlukan upaya pengayaan jenis pohon penaung agar keanekaragaman hayati, stabilitas ekosistem, dan keberlanjutan pengelolaan kawasan dapat terus ditingkatkan

Forests play a crucial role in maintaining ecosystem balance through biodiversity, carbon storage, soil conservation, and microclimate regulation. One form of land management that maintains ecological functions while providing economic benefits to the community is the coffee agroforestry system. In Ketol District, Central Aceh Regency, most coffee plantations are managed under a social forestry scheme by Forest Farmer Groups (KTH). However, information on the structure and composition of vegetation in this agroforestry system is still limited, necessitating a study that can quantitatively describe vegetation conditions. This study aims to analyze the structure and composition of vegetation based on vegetation density using the Normalized Difference Vegetation Index (NDVI) as a basis for stratification. The results can serve as a reference for sustainable, scientifically based coffee agroforestry management. The research was conducted in November-December 2025 in three Forest Farmer Groups, namely Bintang Pepara Village, Kekuyang Village, and Bah Village, Ketol District, Central Aceh Regency. Sampling used a purposive sampling method based on vegetation density classes resulting from NDVI classification. Vegetation data were collected through field inventories at the seedling, sapling, pole, and tree levels, then analyzed using the Important Value Index (INP), Shannon-Wiener Diversity Index (H'), Evenness Index (E), and Margalef Species Richness Index (Dmg). The results of the study indicate that the coffee agroforestry system in the three locations has a layered vegetation structure consisting of seedling, sapling, pole and tree levels, with a vegetation composition dominated by coffee (Coffea arabica) as the main crop and several shade trees such as avocado (Persea americana), lamtoro (Leucapa leucocephala), gamal (Gliricidia sepium), durian (Durio zibethinus), candlenut (Aleurites moluccanus), and cinnamon (Cinnamomum verum). Bintang Pepara Village has the highest number of vegetation individuals of 230 individuals, Bah Village has 209 individuals, while Kekuyang Village has 48 individuals. Analysis of the vegetation structure shows that Bah Village has a relatively denser canopy closure, Bintang Pepara Village has a fairly even vegetation distribution, while Kekuyang Village shows a more open canopy structure. The diversity, evenness, and species richness values ​​in the three locations are generally in the low to moderate category, which indicates the dominance of several main species, especially coffee and certain types of shade trees. These results indicate that the coffee agroforestry system in the social forestry area of ​​Ketol District is still able to maintain ecological functions through the existence of a multi-level vegetation structure, but efforts are needed to enrich the types of shade trees so that biodiversity, ecosystem stability, and sustainability of area management can continue to be improved.