Agrobiodiversity Chapter 1 PDF

Welcome to my class Agrobiodiversity October/2024  course name: AGROBIODIVERSITY Cr Hr: 2(1+1)/3 module name: Agroforestry System and Management pre-requisite: none course code: AgFo4066 target group: Agroforestry student assessment: continuous(50%) + fi...

Welcome to my class Agrobiodiversity October/2024  course name: AGROBIODIVERSITY Cr Hr: 2(1+1)/3 module name: Agroforestry System and Management pre-requisite: none course code: AgFo4066 target group: Agroforestry student assessment: continuous(50%) + final exam(50%) grading system: fixed scale instruction policy 85% and 100% attendance of lecture and practical session respectively switch off or silent your mobile don’t be late (5min.) avoid side talk raise unclear terms in class  prescribed literature Agrobiodiversity, F.A.O., 2018. A training manual for farmer groups in East Africa. Rome: Food and Agriculture Organization of the United Nations. Almekinders C. and De Boef W. (2000). Encouraging Diversity, conservation and development of plant genetic resources. Intermediate technology publications. Ashton, MS and Florencia, M. 2000. Silcvicultural basis for agroforestry systems. CRC. Press Darshan K. H. (1999). Biodiversity and Sustainable Conservation. Science Publisher. Gaston K.J. (1996). Biodiversity. A Biology of Numbers and Difference. Blackwell Science. Paul E. A. (1989). Soil Microbiology and Biochemistry. Academic press, INC, New York William J and Sutherland, (eds) 2006. ecological census techniques. Cambridge.  Chapter 1: Basic Concept of Biodiversity The 1992 United Nations Earth Summit in Rio de Janeiro defined; “Biological diversity" "the variability among living organisms from all sources, including, terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems".  Cont.., One of the best definitions of biodiversity is; “the structural and functional variety of life forms at genetic, population, community, and ecosystem levels.” this definition is especially helpful because it focuses on the two ideas that make biodiversity a workable concept biodiversity is the entire collection of biological variety, not simply a collection of individual species. variety that defines biodiversity exists at multiple biological levels. therefore, biodiversity hold the whole of `life on earth'.  Agrobiodiversity subset of biological diversity important to food & agriculture. the human element that sets agrobiodiversity apart from ‘wild’ biodiversity: agrobiodiversity is the outcome of the interactions among genetic resources, the environment & farmers’ management systems & practices. It is the result of both natural selection and human intervention over millennia.  Agrobiodiversity the diversity of plants, animals, fish, trees and microbes that are used directly or indirectly for food and agriculture. agrobiodiversity is the foundation of sustainable agricultural development. human race could not survive without access to this diversity, which enables plant and animal species and agroecosystems to evolve and adapt to changing environmental conditions.  Cont…, gains in productivity, improve sustainability, improve livelihoods for the rural poor and meet the challenge of changing production conditions (climate change, population growth, urbanization & an increasingly degraded environment). Agricultural production systems need to be focused more on; effective conservation and management of biodiversity & ecosystem services to meet triple objectives of (environmental sustainability, food security & improved livelihoods).  Cont.., CBD’s thematic program on agrobiodiversity identifies four dimensions of agrobiodiversity (CBD, 2011): variety & variability of animals, plants & micro- organisms (crops, livestock, forestry and fisheries). diversity of genetic resources (varieties, breeds, cultivars) diversity o f non-harvested species that support production (soil microorganisms, predators, pollinators) diversity of the agroecosystems  Dimensions of agricultural biodiversity 1) Genetic resources for food and agriculture plant genetic resources (crops, wild plants harvested and managed for food, trees on farms, pasture and rangeland species) animal genetic resources (domesticated animals, wild animals hunted for food, wild and farmed fish and other aquatic organisms) microbial and fungal genetic resources. main units of production in agriculture, & include cultivated & domesticated species, managed wild plants & animals, plus wild relatives of cultivated & domesticated sps.  Cont.., 2) Ecosystem services upon which agriculture is based. include a diverse range of organisms that contribute at various scales to; inter alia nutrient cycling pest and disease regulation Pollination pollution and sediment regulation maintenance of the hydrological cycle erosion control, and climate regulation and carbon sequestration.  Cont.., 3) Abiotic factors local climatic and chemical factors and the physical structure and functioning of ecosystems, which have a determining effect on agricultural biodiversity. 4) Socio-economic and cultural dimensions. Agricultural biodiversity; largely shaped and maintained by human activities and management practices large number of people depend on agricultural biodiversity for sustainable livelihoods include traditional & local knowledge of agricultural biodiversity, cultural factors and participatory processes, and tourism associated with agricultural landscapes.  Cont.., ❖ agrobiodiversity concerns three levels of genetic diversity: agroecosystems species (inter-specific diversity) and within species (intra-specific diversity) ❖ genetic variation within species includes wild relatives, landraces and modern cultivars, plus materials in ex situ collections. ❖ variation within a genepool allows breeders and farmers to develop new varieties that improve productivity, quality, tolerance to drought or resistance to pests and diseases. allows species’ continued evolution & adaptation to changing environments, including climate change.  Generally, Agrobiodversity is “variety & variability of animals, plants & micro-organisms used directly or indirectly for food & agriculture. it comprises the diversity of genetic resources (varieties, breeds) and species used for food, fodder, fiber, fuel & pharmaceuticals. it also includes the diversity of non-harvested species that support production, and those in the wider environment that support agroecosystems as well as the diversity of the agroecosystems.  Generally, Agrobiodversity is Agricultural biodiversity, also known as agrobiodiversity or the genetic resources for food and agriculture, includes: Harvested crop varieties, livestock breeds, fish species and non domesticated (wild) resources within field, forest, rangeland including tree products, wild animals hunted for food and in aquatic ecosystems (e.g. wild fish); Non-harvested species in production ecosystems that support food provision, including soil micro-biota, pollinators and other insects such as bees, butterflies, earthworms, greenflies; and Non-harvested species in the wider environment that support food production ecosystems (agricultural, pastoral, forest and aquatic ecosystems).  What is conservation? “... Conservation is the scientific study of the nature & of earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions.” It includes: management preservation maintenance sustainable utilization restoration and enhancement of the natural environment.  Division of Biodiversity this variety of life on earth (biodiversity) can be observed or described at three levels; 1. genetic level the variability within a species (genetic diversity) 2. species level the variety of species within a community (species diversity), and 3. ecosystem level the organisation of species in an area into distinctive plant and animal communities constitutes ecosystem diversity.  A) Genetic Diversity Genetic Diversity; - differences in DNA among individuals – variation in the genetic composition of individuals in a population, community or species – due to chromosomal/sequence mutation, and physical or behavioral isolation of populations (speciation) – allows individuals to adapt to different conditions. – high genetic diversity increases ability of populations and species to survive major changes in their environment (e.g. climate change)  Chromosome structure gene gene gene gene chromosome DNA Structure A T T A T A Bases G C C G A = adenine T A G C T = thymine G C A T C = cytosine C A G T G = guanine T A  Evolutionary Processes 1) Natural Selection 2) Gene Flow 3) Genetic Drift  2) Gene Flow Population A A Species A gene barrier time reproductive flow arises isolation Population B B Species B  B) Species Diversity Species diversity; variety of species in a given area – variety of species (group of interbreeding organisms) in a particular habitat or ecosystem. – number of different species in a particular area and their relative abundance. – Species richness, the number of species living in a habitat or other unit, is one component of biodiversity. – Species evenness is a component of species diversity based on relative abundance (the number individuals in a species relative to the total number of individuals in all species within a system)  C) Ecosystem Diversity Ecosystem diversity; variety of habitat, ecosystem & communities variation in all living and non-living things in a particular geographic or ecological region. array of living & non living thing + interaction of organisms with each other and with their physical environment the variety of habitats, biotic communities and ecological processes have their own complement of distinctive & inter linked species based on the differences in the habitat.  Cont.., – have specific geographical region, or a political entity such as a country or a state. – include landscapes such as forests, grasslands, deserts, mountains, etc., as well as aquatic ecosystems such as rivers, lakes, and the sea. – each region also has man-modified areas such as farmland or grazing pastures. – ecosystems comprise unique combinations of animals, plants, micro organisms and physical characteristics that define a location.  Cont.., ❑ Generally two key terms in ecosystem; 1) Ecosystem function the processes going on in ecosystems; photosynthesis, nitrogen take-up, nutrient cycling, energy production and conservation 2) Ecosystem resilience refers to ability to restore function after stress higher biodiversity -> higher resilience  Origin and nature of Agrobiodiversity Agrobiodiversity; the result of the interaction between the environment, genetic resources and management systems and practices used by culturally diverse peoples encompasses the variety and variability of animals, plants and microorganisms that are necessary for sustaining key functions of the agroecosystem local knowledge and culture - considered as integral parts of agrobiodiversity (human activity of agriculture that shapes and conserves this biodiversity)  Origin and nature of Agrobiodiversity Agrobiodiversity; ancient practices of humans domesticating & cultivating plants & animals. encompasses variety & variability of animals, plants, and microorganisms used directly or indirectly for food & agriculture. shaped by humans through cultivation, breeding, and conservation. farmers developed d/nt crops & livestock breeds over thousands of years diversity enhances food security, promotes sustainable agriculture, & preserves cultural heritage. unlike wild biodiversity, it is intertwined with human practices & land use.  Origin and nature of Agrobiodiversity Agrobiodiversity is central to overall Biodiversity Biodiversity. mixed agroecosystem crop species/varieties livestock and fish species plant/animal germplasm Agrobiodiversity soil organisms in cultivated areas bio-control agents for crop/livestock pests wild species as landraces or with breeding The concept of agrobiodiversity in agriculture has emerged cultural and as a result local of, of diversity knowledge In agriculture, each species has its role in food chain and the nature of the agricultural environment is dependent on crop and animal diversification