Agroforestry systems support life around them by enhancing wildlife habitat and ecosystem biodiversity and resilience. They provide food and shelter for many species, such as birds and insects, and let plants withstand abiotic (temperature, humidity, salinity, soil pollution) and biotic (pathogen and parasite resistance).

In an agroforestry system, different organisms are able to coexist and depend on each other for growth and survival. Trees provide adequate shade for both above-ground and below-ground organisms. They help protect them from harsh weather conditions and predation while also serving as a good habitat for other animals.

Agroforestry achieves several positive outcomes, not just food security alone, unlike conventional farming systems. It builds the ecosystem by attracting diverse life forms ranging from microorganisms to larger animals like birds, insects, rodents, reptiles, and several others. In return, these organisms provide ecological services such as pollination, soil aeration, the breakdown of organic matter, and so on.

By restoring, preserving, and enhancing biodiversity and by improving microbial activity in soil, agroforestry systems lead to:

• more sustainable food systems
• better health of livestock and fauna helping them adapt to climate change
• higher quality of forage and food
• social and economic sustainability of farmers
• improved soil fertility and water quality while preserving the health of our ecosystems

Biodiversity and its loss

The European continent is home to a wealth of habitats and species. Centuries of human activities, however, have taken a toll on Europe’s biodiversity.

The term “biodiversity,” derived from the Greek “bios” (life) and the Latin “diversitas” (variety), refers to the variety of living organisms that make up our natural environment, including all the varied species of animals, plants, fungi, and even bacteria. These organisms interact in complicated web-like ecosystems to keep things in balance and support life. The security of food and nutrition, energy, the creation of medications, and the demand for freshwater, which collectively sustain good health, are all supported by biodiversity.

Biodiversity has been declining in recent years primarily as a result of human activities including  changes in land use, pollution, overexploitation, and climate change. According to a United Nations report published in the year 2019, researchers warned that nearly one million species risk becoming extinct within decades, while current efforts to conserve the earth’s resources will likely fail without radical action. Also, according to estimates, 20% of the Amazon rainforest has disappeared in the last 50 years due to continuous deforestation, which has already had a negative impact on biodiversity and accelerated climate change.

Agroforestry has the potential to stop biodiversity loss on a global scale, particularly in tropical regions. Agroforestry can ease pressure on forest ecosystems by supplying forest products. Agroforestry prevents habitat damage by lowering erosion and flood events. Since eroding soil can cause lakes and rivers to become eutrophic, this is also advantageous for aquatic animals and plants.

All life forms are vital

Every organism is important in an ecosystem. This is the major reason why agroforestry practices are targeted at restoring biodiversity. Some of these organisms serve as natural checks (biological control) in maintaining the population threshold of certain potential plant pests. When these organisms serving as biocontrol agents are lacking (due to factors such as deforestation and monocropping), a surge in the population of plant pests is experienced, thereby causing a devastating loss in crop yield. This phenomenon is common in the conventional farming system. Also, certain herbivores, while feeding, tend to transport ingested plant seeds over long distances before finally ejecting them as waste. These seeds tend to grow under favorable conditions into healthy plants, thereby contributing to the buildup of the ecosystem.

Additionally, certain decomposers feed on decaying organic materials and break it down into chemical energy that is then released back into the soil for plants to use. They are able to modify nutrients so that plants may use them, creating healthy soil that will support the growth and development of a complex vegetation community. Some organisms with such ability include fungi, bacteria, insects, worms and others. Also, insects such as bees help in pollinating flowers, thereby maintaining plant reproduction and density in the ecosystem.

The buildup process of biodiversity in an agroforestry system

The buildup of diverse organisms in any ecosystem takes time. When trees are grown in an agroforestry system, different biotic communities gradually replace one another until a climax community (such as a mature forest) is reached. Factors such as the accumulation of organic matter (from dead leaves and twigs), changes in soil nutrient composition and other soil properties, and the water retention capacity of the ecosystem bring about the settlement of new biotic communities. This process is gradual but causes changes in species structure and increases the diversity of species.
It is, however, necessary that when developing an agroforestry system, the right plant combinations are selected, as different organisms are attracted to different plant species. For instance, hummingbirds tend to prefer red or orange flowers that are tubular in shape. Beetles prefer white or green, bowl-shaped flowers. Native ivy is known to attract different species of wildlife, such as birds, mammals, butterflies, bees, hoverflies, and other useful insects. Also, many of the beneficial effects of agroforestry on biodiversity can be undermined by the absence of non-native plants in agroforestry system.