Status, utilization, and conservation of agrobiodiversity in farms: a case study in the northwestern region of Bangladesh

Agrobiodiversity is important not only for environmental stability but it also supplements the local livelihood. The level of dependency of the locals on agrobiodiversity is even more intensive in an area where there is no recorded government forests or protected areas. A total of 145 households were surveyed to explore the agrobiodiversity status in the farmlands of Ullapara upazilla in Sirajganj District, Bangladesh, where protected areas do not exist. A total of 37 tree species belonging to 22 families including timber, fruits, fodder, fuelwood, and multi-purpose tree species (MPTS) were recorded. The most common species was Eucalyptus camaldulensis (83%) followed by Swietenia macrophylla (60%). The average tree density for the whole study area was 87.35 ± 9.28 trees per ha. The mean value of Shannon–Wiener index and evenness of species were 3.33 and 2.12, respectively, with larger farms having the highest tree species diversity and marginal farms having the lowest. Actual farm size and the species diversity were found positively correlated (Spearman's ρ = 0.33, n = 145, p ≤ 0.01). Five types of cereal crops and two types of common vegetables were grown. Mean production of all agriculture crops was the highest on the large farms. Chicken and duck were the major livestock in the study area. Farmland, like other agroforestry systems, maintains a level of tree species diversity along with crop and livestock diversity which may contribute to biodiversity conservation in least forest areas and supply diverse products and generate income for farmers as means of their existence.