What is an ecosystem?
An ecosystem describes an environment and all the living organisms within it, such as plants, animals and other organisms, along with the interactions that occur between all the different elements. Ecosystems are vital to human existence as they provide people with water, food, building materials and other essential items.
How have they become degraded?
Around the world, ecosystems have become degraded or damaged, reducing their capacity to provide food and water and negatively impacting biodiversity. The UN categorises ecosystems into eight main types: farmlands, forests, lakes and rivers, grasslands and savannas, mountains, oceans and coast, peatlands and urban areas. All types are affected. Degradation has resulted from the intensification and industrialisation of agriculture; expansion of crop and grazing lands into native vegetation, unsustainable agricultural and forestry practices, pollution, and climate change.
Planting monocrops, the use of fertilisers and pesticides, and industrialised livestock production have helped with food supply across the world but to the detriment of many ecosystems. It has been established that about 75% of global land has been substantially impacted by us humans (see this IPBES assessment report for more details). We can feel very disconnected from this degradation if we do not live in a place that bears witness to it or its effects. However, overconsumption in developed countries and increasing consumption in developing countries play a huge part in driving this degradation.
What needs to happen
Ironically, the benefits to reversing land degradation are increasing food and water security, and helping the adaption to and mitigation of climate change. In light of the seriousness of the situation, June 2021 sees the launch of the UN decade on ecosystem restoration, aiming to enhance peoples’ livelihoods, counteract climate change, and halt the collapse of biodiversity. The good news is that we already know of many ways in which ecosystems can be restored or managed to limit degradation. For example, with land restoration, practices include conservation agriculture (no tilling-agitating the soil between crops), regenerative agriculture (no tilling, no or minimal pesticides/synthetic fertilisers, diverse crops rotated), agroforestry (combining crops and trees) and silvopasture (combining pasture for grazing and trees).
Restoring ecosystems in action
Examples of successful ecosystem restoration can be viewed in the documentary by John D. Liu, Regreening the desert, such as the impressive transformation of part of the Loess Plateau in China. The land was completely unproductive, with eroded soil causing dust storms to blow into neighbouring towns and cities. When it rained, silt blockages formed in the river and consequently led to floods. Local people were incentivised to take their animals off the land and work to restore it. Trees were planted at the top, terraces were constructed in the middle and a dam built at the bottom.
It was John’s idea that initiated the Ecosystem restoration camps global movement. They are one example of an organisation aiming to repair broken ecosystems, restore biodiversity and improve the livelihoods of communities, through the collaboration of local people and visiting campers. Pieter van der Gaag, their Executive Director, gives an excellent account of how the organisation is playing their part, on episode 5 of the podcast. They practice regenerative agriculture to improve soil fertility and reduce soil erosion, enabling plant and animal life to proliferate. The camps provide a way for local communities to engage in sustainable livelihoods, whilst giving campers a meaningful experience, where they can connect with how their food is sourced.
The importance of soil
Highly fertile soil is at the centre of restoring land, as it: provides the largest water filter and storage tank; supplies plants with nutrients and water and provides stability for their roots; contains more carbon than the vegetation grown above ground; hosts a huge variety of diverse organisms essential for healthy ecosystems. When the soil is in good shape, it acts as a carbon sink, when degraded it erodes and becomes a carbon source. It is important to keep carbon in the ground, for both climate change mitigation and providing resources for growing plants. Strategies to do this could involve: keeping the ground covered by plants, such as using cover crops between cash crops (e.g. wheat, maize); planting as many different species as possible (rotating crops); and interfering with the soil as little as possible (e.g. no tilling), as indicated in this article.
Our impact on ecosystem restoration as individuals may be limited, but at least we can respect and look after the land we have access to, such as our gardens. So, it seems that growing as many different plants as possible to cover as much ground as you have, without too much interference, could be a good idea.