How farming changes ecosystems, how abandoned land recovers through succession, how carrying capacity and biodiversity respond, and how social insects and predators support nature-based farms.
Agriculture’s share of a country’s economy can fall even while its impact on land stays large, so data on land cover are as important as economic data.
Succession is the gradual change in the species that make up a community over time.
On abandoned farmland, pioneer species such as annual grasses and herbaceous plants colonise first, followed by shrubs and small trees, until a stable climax community such as closed woodland develops. Biodiversity usually increases during succession.
Carrying capacity is the maximum population an environment can support sustainably. More habitat diversity — different plants, root depths and food sources — supports more species and can raise carrying capacity. When a herbivore population exceeds carrying capacity, signs include overgrazing, bare soil, erosion, poor animal condition and starvation.
Species can coexist by using the same resource in different ways (resource partitioning), for example plants with shallow and deep roots taking water from different soil layers.
Nature-based (regenerative) farming works with ecological processes instead of relying only on chemical inputs:
Honeybees are eusocial: a colony has one fertile queen that lays eggs, a few drones (males) that mate with queens, and many sterile female workers that collect nectar and pollen, care for larvae, build comb and defend the hive. Division of labour lets the colony do many tasks at once, so it gathers food efficiently and survives better than individuals alone.
On diverse, nature-based farms bees find flowers over a longer season, so they face less food scarcity and colonies can grow larger.