| Abstract | In managed landscapes, tree-dominated habitats such as homegarden often show promise for biodiversity conservation. In Bangladesh where natural forest cover is less than 10%, homegardens, which are maintained by at least 20 millions households (2% of the country's total land area), represent possible strategies for biodiversity conservation and livelihood outcomes. Three main objectives were addressed in this study. First, this study investigated the total botanical diversity and structural characteristics of the homegardens. Second, this study investigated whether household's contextual attributes have quantitative and predictable relationship with homegarden biophysical conditions. Third, to describe the overall management practices of the homegarden. Data were collected from 402 randomly selected households (totaling 45.2 ha area) in six major regions or districts across southwestern Bangladesh. All plants except small grasses were censused, totaling 419 species (146 trees, 67 shrubs, 150 herbs, and 56 woody and non-woody climbers) with 109 families. Each region contained a mean of 293 species in a mean of 67 sampled homegardens. Trees and herbs predominated and accounted for about 71% of the recorded species. Seventy-five percent of the species were cultivated and 59% were native to the Indian subcontinent. Approximately half of the ten most important trees and climbers were native, but exotic shrubs and herbs, particularly Citrus limon and Musa spp. dominated shrubs and herbs respectively. Six species were on the Bangladesh IUCN Red List. Most households focused on only two Red Listed species (Andrographis paniculata and Calamus guruba); otherwise there was a low rate of integrating Red Listed plant species into homegardens. The median homegarden of 800 m² contained a mean of 34 species (range 2-107). An average homegarden contained 107 individuals of trees and shrubs (1003 per hectare). An average of three (range: 2-5) vertical strata was common in a mean homegarden. The middle canopy constituted the highest proportion (44%) of all the species and individuals of a mean homegarden. All recorded species were useful for nine major categories. Forty percent species were found multipurpose. Homegardeners placed a premium on planting fewer, highly favored plant species for fuelwood, timber, and fodder. Majority (36%) species were used for food. Thirty-one percent of the species were used to earn cash from the sale (was not an end use) of surplus homegarden products after subsistence consumption. In general, native plant species were more commonly used for all purposes except commercial and food. Across the southwestern region there is a significant botanical richness contained in homegardens. Compared with other published studies, southwestern Bangladesh homegardens represent greater relative importance to biodiversity conservation than most other parts of Asia, and possibly the tropical region generally. Despite the high species richness and moderate level of species overlap (average 68%) across six regions, majority species were rare. Fifty-six percent of all species were found in 20 or fewer homegardens and 82% in 50 or fewer homegardens. Sixty percent of all species of trees and shrubs had 50 or fewer individuals each. Same was valid for native and IUCN Red Listed species for Bangladesh. Thus, whereas richness across the landscape was high, serious effort must be made to increase the populations of rare species and their conservation. This study proposed three main conservation activities: (1) awareness building about the status and importance of rare species, (2) protection of existing individuals of rare species, and (3) propagation of rare species. Overlaying all of these activities is the inclusion of local communities in the process, who were the ones to retain these plant species in homegardens in the first place, and the stakeholders who will determine whether homegardens indeed act as long-term repositories to biodiversity conservation. Lack of quantitative surveys on the floristics of Bangladesh's primary forests restricted this study to test the level of floristic similarity with homegardens need to be investigated in future studies. Many frugivorous birds and bats, reptiles, amphibians, insects, and small mammals were observed in homegardens during botanical inventory of this study. The diversity of wildlife in homegardens will be a reflection on the structural complexity of the vegetation which could make homegardens attractive to, and serve as important refuge for wildlife in Bangladesh. Further study on the use of homegardens by wildlife, and the role of structure in wildlife use, should be undertaken to understand how to maximize the wildlife value of homegardens. Household contextual attributes are said to be influential on the homegarden biophysical conditions. Biophysical, demographic, and socioeconomic attributes of households were analyzed to develop quantitative and predictable relationship with homegarden biophysical conditions using multiple regression analysis. The moderate to low regression R² value revealed that most household characteristics were not strong predictors of homegarden biophysical attributes. Despite the moderate to low explanatory power of the model, time spent and homestead size were the most important factor positively influencing species richness and income in a homegarden. Given the positive relationship between homestead size and the number of species and vast majority homegardens primary management objective in southwestern Bangladesh supports the general hypothesis of subsistence homegardens. Rapidly increasing number of homesteads with the growing population may act as biodiversity islands and may support country's biodiversity conservation efforts. Market access generally influences homegardens species composition and structure depending mainly on the homegarden management objective. The general hypothesis of subsistence homegarden is that the stem density and species richness in the homegarden are less influenced by the market economy. The negative influence of easy accessibility to the market and positive influence of the distance to the market on the species richness in southwestern Bangladesh homegarden supports the general hypothesis of subsistence homegardens. Therefore, long-term influence of the market on the homegarden's attributes needs to be investigated in future studies to test whether the general hypothesis of species loss from the homegardens due to commercialization could take place in Bangladesh context. Homegardens in southwestern Bangladesh have traditionally been managing for generations. Site preparation, species selection, planting, tending, harvesting, and use of products were the main management activities for vast majority of the households. Food, timber, fuelwood, medicinal, and fodder were the five most preferred products from the homegardens. Seeds and seedlings were the main planting materials used for homegarden propagation. Local market was the main source for planting materials for 81% of all required planting materials. Direct seed sowing mainly for annuals and seedlings transplant mainly for perennials were the two main methods used for 91% of the species. Plants position in the homegarden clearly follows both family requirements and plants requirements. Products preference, species and planting materials selection, and careful placement of vegetation in the homestead premises according to the household and plant requirement clearly suggest homegardeners basic understanding of plant management in their homegarden. The most common problems of homegarden management were lack of quality and timely supply of planting materials, land shortage, and lack of finance. Thus, ensuring timely and quality planting materials supply to the homegardeners is important for better establishment and development of homegardening systems in Bangladesh. Capacity building among the homegardeners on nursery techniques is vital to overcome planting materials shortage and timely supply problems from the market. Research, training, and academic institutes could take important part in this endeavor. Given the primary subsistence management objectives, multiple-species-storied structure, and local traditional management practices, southwestern Bangladesh homegardens at this moment seem least affected by the identified threats to homegardens mentioned elsewhere |