**1. Introduction**

Agriculture and food systems are both drivers and recipients of major changes in global health and socioeconomic systems in this era of intense human interaction with the planet "Anthropocene" [1]. The agricultural sector is challenged to fulfill the food and nutritional requirements of ever-increasing population [2–4]. For instance, feeding 9.7 billion people in 2050, and 11 billion in 2100, is one of if not the most important challenge facing mankind during the remaining years of the century. Global population, which was only 1.7 billion at the turn of the century in 1900, is now 7.3 billion. The world has added approximately 1 billion people in the span of the last 12 years. It is expected to climb to 9.7 billion by 2050, and to 11 billion at the end of this century in 2100. Globally, 870 million people are currently chronically hungry and 2 billion are malnourished. Rates of growth in crop productivity have declined, among many reasons is due to climate change and the decline of water and land resources.

In an attempt to safeguard food security, the homogenization of the agricultural system through the green revolution led to a calorie-based food system [5]. It is only less than 20 plant species out of 5000 that are key source of food [4]. Such scenario has led to 40% of arable land globally be dedicated to only three crops which are wheat, maize, and rice. These crops are the main focus of plant breeding programmes, account for the largest share of the global seed market, they are depended for calorie requirement by over 50% of total food intake and are excessively prioritized [2]. Although these crops have contributed to resilience and long-term sustainability of human wellbeing, but the dependence on such few crops has countersigned loss of biodiversity and decline in crop productivity [6].

Agrobiodiversity which is defined as the variety and variability of animals, plants and micro-organisms that are used directly or indirectly for food and agriculture, including crops, livestock, forestry and fisheries as the key driver of the ecological transition of agriculture. Agrobiodiversity is significant to resilience to environmental risks, socioeconomic shocks, adaptation and mitigation to climate change. It delivers valuable and response diversity to agroecosystems, potentially making them more robust, and may offer solutions to prevent pests and diseases and it plays an important role in nutrients recycling, soil organic matter maintenance and reduces the need for chemical pesticides and fertilizers. It also creates more favorable habitats for useful macro and micro-organisms and then improves soil quality. Its interactions with farmers provide key dimension of human and nature in agro-systems [7]. The genetic diversity of traditional varieties of crop in agrobiodiversity is the most economically valuable part which is crucial for future world crop production [8]. Therefore, this review intends to explore the contribution of Traditional African Vegetables (TAVs) as a biodiversity component in the livelihood of Tanzania rural communities and how these communities can conserve TAV species.
