Agriculture is, in its nature, explicitly a management of biodiversity, although in recent centuries it has tended to be a struggle against it. To date, human activity has aimed unilaterally to increase positive production effects by eliminating biodiversity. Of the approximately 750 plant species cultivated and constituting the food of the world’s people in past centuries, only 30 species are currently important, and only three (wheat, rice, maize) constitute the food base of humanity (FAO, 1997). Today, 12 plant species and 5 animal species provide 70% of the food needs of more than 7 billion people.
As a result of the expansion of agriculture, there has been a huge depletion of species, expressed by:
- loss of habitat for unsupported species,
- species extinction,
- reducing gene diversity in crop populations.
Since the 1960s, the Earth’s cultivated area has increased from 1280 to 1400 million hectares, so biodiversity has been reduced on a further 120 million hectares. This trend can only be reversed by increasing the productivity of agricultural areas, which will reduce the cultivated area to around 1,250 million hectares.
Biodiversity and agriculture are very closely linked. Insect-friendly agricultural land, abundant in food and providing shelter, influences increased food production. It is known that the lower the agricultural intensification, the greater the diversity of plants and animals in the fields, which attracts numerous birds, insects etc. to them. However, intensive production in a specific area of land must not have a limiting effect on the biodiversity around it.
It is possible to speak of functional biodiversity for agriculture as it provides:
- proper soil structure and function
- soil fertility and productivity
- plant pollination
- habitats of natural enemies of crop pests
- protection against water and wind erosion
- nutrient cycles in nature (including waste decomposition)
- controlling the correct water cycle in nature
- diversity of organisms in a changing climate
- maintaining good living conditions for local communities
Protecting biodiversity is one of the priorities of any agri-environmental programme. The preservation of wildlife habitats is very important for agricultural production, as the presence of many and diverse beneficial organisms promotes crop protection. It is important to plan and maintain habitats for wild plants and animals in a way that favours their movement through the agricultural landscape – in the form of so-called ecological corridors. Areas where management is difficult (escarpments, ponds, thickets, wetlands, afforestation and mid-field shrubs) can be used as non-agricultural areas – eco-livestock. If such habitats are located on the farm, care should be taken to ensure that they are connected by a system of ecological corridors, which can be baulks, drainage ditches, roadside paths. In creating such a network of sites and corridors, consideration should be given to the animals for which it is to be useful. Areas of high biodiversity, with a diverse spatial structure (groups of trees, shrubs, ditches, etc.) are much less susceptible to damage from strong winds, fire, drought or flooding. In a diverse landscape made up of a mosaic of different ecosystem types, such events are naturally reduced and cause less damage.
Agriculture, which in Poland covers about 60% of the country’s area, limits biodiversity in the area. Biocoenoses of cultivated fields, referred to as agrocenoses, are characterised by a small, man-determined number of plant species and their abundance, in contrast to natural biocenoses. They cannot function without human intervention and very significant changes in them occur annually. Plant protection in any form, including integrated plant protection, can be a particular threat to biodiversity, as by favouring a selected plant species it limits the others. However, it should support the development of those organisms that do not harm but actually help crops by providing increased soil fertility, proper air-water relations and nutrient cycling.
The varied spatial structure of the environment in the vicinity of fields is of great value, as it harbours a diversity of organisms that stabilises the agrocenosis biologically. It is worth remembering that preserving biodiversity is a prerequisite for maintaining soil fertility and agricultural productivity. Protecting biodiversity will pay off in yield and quality.
As the human activity closest to nature, agriculture therefore has a huge responsibility to protect biodiversity and keep it as healthy as possible.
Farmers can prepare for extreme weather events. Caring for biodiversity provides opportunities for farms to consciously diversify production – growing different species and varieties of plants to reduce the negative impact of, for example, drought or excess rainfall on the production and financial effect achieved.
Agricultural biodiversity plays an important role in preserving the cultural identity of local communities. This includes the transmission of traditional medicinal plant knowledge, recipes, as well as cultural rituals and folk festivals.