**1. Introduction**

The most complex and uncertain natural disaster is drought, even it is difficult to predict and mitigate due to numerous factors, magnitude as well as difficulties in defining a drought. Drought causes impacts on agro biodiversity in many ways [1]. Agro biodiversity is the part of biodiversity includes both genetic diversity and crop and animal diversity in diverse agro ecosystem and different agriculture [2, 3]. It was mentioned that agro biodiversity is essentially important for sustainable development both for natural and anthropogenic as well as livelihood [4, 5]. Homestead is the traditional place and promising option for plant species conservation [6]. These efforts may help mitigate ecosystem degradation and drought impacts while providing food and economic opportunities to rural people. In the homestead, members share responsibilities and distribute gardening tasks among themselves. Women like to use homestead products for household consumption and gifting and men for sale and cash income [7]. Numerous studies in the world showed that homesteads are the place of the highest plant diversity for crops and non-crops [8]. A study mentioned that agro

biodiversity support sustainable agriculture [9]. Food and Agricultural Organization-FAO [10, 11] estimated that there are 2, 50,000 to 5, 00,000 plant species in the world. According to a study, in agriculture only 1,500 plant species are being used. Another study mentioned that agrobiodiversity exists at the varietal level though number of crop species is low [12]. Agrobiodiversity provide three types of value such as use value, option value, and existence value [13]. Ecosystems that maintain naturally are considered as the major support for sustainable production and enhance food and livelihood security at local to global scale [2, 5, 14]. Agro biodiversity is contributing to agricultural production, maintaining ecosystems and human food security [12, 15–17]. Ecosystem provides four major categories of services include provisioning services, supporting services, regulating services and cultural services. Benefit may get through intrinsic values (cultural and social) and supported by biological diverse system [15].

Agro biodiversity provides diverse benefits including nutritious diets (fruits and vegetables) for human health; longer productivity; adaptation to changing conditions; and conservation methods for enabling future use. Biological diversity reduces the general risk of economic and ecological failure at individual (farmer) level as well as on global scale while making those systems more sustainable and less susceptible facing the future challenges [17–19]. Diverse agricultural production system may be less threatening to biological diversity compared to highly intensified and uniform systems, such practices still do enhance pest damage, competition for water, soil, nutrition and pollinators, result in habitat and nutrient loss and have a negative effect on non-target species [20]. The reduction of agro biodiversity is closely linked to the loss of productivity, while threatening ecological stability, the security of food supply and livelihood worldwide [15]. Strategies for identification and conservation of agro biodiversity are lacking and hence, there is need to develop indices for identification of important component of agro biodiversity, food and nutritional security. Agro biodiversity has been disturbed due to switching from rain-fed agriculture to irrigated agriculture. Increasing frequency of extreme weather patterns and droughts are going to be the most important climatic factors affecting agro biodiversity [21, 22]. Diversity has been accounted at three levels such as alpha, gamma and beta [23]. Diversity at alpha level could be measured at community level, beta for composition (change from farmers to farmers) and gamma at the larger units [2, 24]. The assessment of drought impacts on homestead plant diversity in the Barind Tract is essentially important. The study was conducted with the view to assess and compare drought impacts on homestead plant diversity in high drought and low drought areas of Bangladesh. The study is also focused on following objectives:


The research elicited following research questions: Research Questions:


*Impacts of Drought on Homestead Plant Diversity in Barind Tract of Bangladesh DOI: http://dx.doi.org/10.5772/intechopen.101885*


Research Hypotheses:

H1: There is a trend of greater homestead plant diversity in the low drought prone area than high drought prone area
