The objective of agroforestry is to promote biodiversity and better management of natural resources. We have already seen the principles of agroforestry here, let's see its impacts on biodiversity and the quality of local ecosystems.
To put it simply, agroforestry is the integration of a mix of trees (and/or shrubs) and farming (crops and animals). At least one of the components is a tree, for the purposes of diversification and protection of the environment and ecosystems. For example, it can be crops mixed with trees, or livestocks and trees, or a mixture of all three.
Trees, through their roots and fallen leaves, promote ideal conditions in the deep layers of the soil, to keep the water and develop mineral supplies for the crops on the surface. Soils that are richer in organic matter are more fertile but also more resistant to climatic hazards and to erosion thanks to the presence of a more developed rooting system. So already, the presence of trees in crop diversification through agroforestry allows the improvement of soil quality.
FERTILE SOILS BRINGS INSECTS
Fertile soils are the natural habitats for many different insects such as beetles, cockroaches, crickets, ants, spiders but also myriapods, such as centipedes and millipedes; and scorpions. Every different type of soil is home to many different arthropod species. Many of these predators eat crop pests, thus helping the crops healthy and the natural competition in check.
INSECTS ATTRACT ANIMALS
When there are insects, the presence of their natural predators of these so-called pest species are also increased, resulting in perfect biocontrol. These insectivores include different kinds of species depending on location and such as opossums, birds, frogs, lizards (e.g. chameleons, geckos), nightingales, swallows, echidnas, numbats, anteaters, armadillos, bats, etc. Some of these, such as birds, also have a great impact on the spreading of seeds.
A PERFECT CYCLE
In return, these insects and insectivores will fertilise the soil and will also help air and keep the soil in mouvement by creating holes and galleries. The movement of particles from lower layers to the surface mixes the organic and minerals together.
They will also help facilitate natural composting as scavengers, and feeding on dead animals and fallen leaves, thereby recycling the nutrients back to the soil. The same soil which the crops and the trees use to grow and produce.
So, in recap, including trees, following agroforestry principles, is perfect for the soil and for the development of local biodiversity which in turn is perfect for the crops.