Ecosystem Changes Caused by Agriculture

Rural areas can be places of great beauty. Fields of corn and wheat, orchards, vineyards – there is so much plenty that nature provides us with! In many ways, land is a communal good: we all partake in the enjoyment of landscapes and we all benefit from the services that our land delivers.

But it is farmers and other land managers such as foresters that have a role in being the stewards of those precious places. And they have done so since antiquity.

Ever since some of the most ancient human settlements, we have been changing the way our natural environment looks for our own benefit and wellbeing. The ancient Romans were responsible for vast deforestation as their civilisation required the use of wood and timber for heating, for making of ceramics and smelting metal, as well as building houses and military equipment such as chariots. Forests were also cleared out to give space to farmland in order to respond to food pressures [1].

Unsustainable farming as the major threat for ecosystems

Over the years, changes to natural ecosystems are to be expected when we claim land for agricultural purposes, but there are some changes that risk irreversibly damaging our land and the services it provides. Modern agriculture with its intensive over-cultivation of our land has greatly contributed to these changes in our ecosystems. Increasingly, the changes inflicted to our ecosystems because of unsustainable farming practices are becoming the number one threat for our planet.

The most immediate change that agriculture inflicts on an ecosystem is the loss of habitat. Land that was previously home to a different species and plants is now converted into fields for farming – very often the land is used for monocultures.

Given population growth and food pressures, it is expected that more land will be converted into farmland by 2050. This means that species and vegetation that originally occupied that land are removed or have to relocate as their original habitat is minimized or sometimes completely eradicated.

These pressures are real and have led many species to become endangered around the globe. For example, the ever expanding palm oil plantations in Indonesia and Malaysia have endangered the local flora and fauna including iconic species such as the Asian elephant, Sumatran rhinoceros, and tigers [3].

But space comes at a premium also in aquatic areas: just because we don’t see the effects as clearly as on land at first sight, it does not mean that aquaculture is not have a negative impact in our seas and freshwater resources. Fish farms are competing for space and resources with wild fish and other marine life.

Loss of biodiversity

Loss of habitat is also a key contributor to biodiversity loss which compromises ecosystems’ ability to deliver on key services such as pollination or water purification. Biodiversity loss is therefore closely linked to habitat loss but also very important change in and of itself. The reason is that biodiversity makes ecosystems more resilient. So, if agricultural land is dominated by monocultures, it will be less able to fight off weather changes or pests.

Experts are unequivocal on this important point: biodiversity is essential for food security and nutrition.

Unfortunately, by converting land into fields for ploughing, we take away the ecosystem’s biodiversity. What is more, by insisting on setting up vast monocultures, we are further compromising the ability of the land to yield produce.

The reason is that monocultures deplete the natural nutrients of the soil which necessitates the use of chemical supplements such as fertilizers and pesticides. This creates a vicious cycle. The agricultural ecosystem that we have created would be much more productive if we invested in crop diversity and ensured the land also benefits from some patches of greater biodiversity, either by keeping parts of the agricultural land uncultivated or introducing trees.

Other harmful consequences of intensive agriculture

A further ecosystem change that agriculture brings about is a direct result of monocultures and the increasing use of chemicals in the form of pesticides and fertilisers. Intensive farming practices are unsustainable and nothing illustrates this more than the amount of soil that is eroded. When natural vegetation is removed, fertile soil can be carried away by wind or rain. This leads to several problems: given that the topsoil contains humus, the part of the soil which has most nutrients, this makes the land less fertile.

Loss of fertile soil leads farmers to compensate with fertilizers which pollutes the environment. The soil that is eroded, along with the fertilisers and other chemicals that are washed away, often ends up in rivers, lakes or the coast where is can cause damage to the aquatic environment by clogging and polluting waterways [5].

As is the case with soil, agriculture is likely to also deplete the water resources of the ecosystem. It is undeniable that agricultural consumes about 70% of the planet’s accessible freshwater. And it is not just the volume of water that agriculture uses that is alarming but the fact that it does so in a very wasteful way.

In many cases, agricultural practices mismanage water resources by cultivating crops that are not suited to the local environment (thereby requiring extraordinary amounts of water), employing wasteful field application methods and using leaky irrigation systems. Very often water resources are directed to agricultural land as illustrated by the example of the Amu Darya River, the longest river in Asia. The river is used to irrigate cotton and other crops in Uzbekistan and Turkmenistan to such an extent that the river no longer flows to the Aral Sea [6].

It would therefore be foolish to ignore the impacts of agriculture on an ecosystem. They are great and varied – in some cases, unsustainable agriculture practices can turn a once fertile land into a desert landscape. But that does not mean to say that there is no happy medium whereby we can pursue agricultural practices while maintaining biodiversity and supporting all the ecosystem services outlined above.

Indeed, there are various methods which allow us to improve the efficiency and productivity of our land by integrating some aspects of natural ecosystems into farmed land. So let’s restore some balance to our agricultural land and let our practices maximise nature’s bounty!