Ecological Succession in Soil Regeneration

Colonisation by Pioneering Species and Ecological Succession in Soil Regeneration

Take a deep breath, that was quite some title. Rather than reading this as a scientific study, we can break this task down and think of it as “what would nature do?”.

In Permaculture, process is very much about observing what you have, looking at what is growing well, why is it flourishing or not? It’s working with nature rather than fighting it. Are we growing the wrong thing in the wrong place, are the soilconditions right?

We don’t have to worry about colonising barren rock, but if we do look a bit deeper. The soil under our feet is largely made up land. The ground feels hard and compacted it’s not like walking through an ancient woodland, why is that?

Colonisation by plants is happening all around us. It can be a gradual thing or to a certain extent we can help speed it up too. If you walk along a street, look at the surface of a wall or a fence. Notice those small lichens or mosses, cracks in the mortar and tiny plants accumulating in the gaps? That’s Colonisation, over time if left to nature those plants will grow, crack the wall. Eventually drop leaves which will decay and provide soil for more plants. A greater diversity of plants, fast growing trees, which will in turn die, decay and build more soil.

In the natural world, disturbances such as forest fires, volcanic eruptions, landslides, or human activities like construction and mining can leave the earth barren, devoid of life. However, nature is remarkably resilient, and even the most disrupted landscapes are eventually colonized and restored through a process known as ecological succession.

In our own little ecosystem at Meadow Orchard we can look at the natural world to see how we can help bring back a biodiverse eco system to the space.

The earth at Meadow Orchard is disturbed ground. From it’s previous use as tennis courts it’s had around 100 years without any real ecology. A thick layer of clinker drainage and a series of clay land drains designed to shed rainwater, the very basic ingredient to support life.

The site has also had forteen years open to the public, soil errosion and compaction of soil, growing food and removing organic material leads to soil loss. Even a task such as sweeping leaves from paths over time causes significant loss of ecology and soil life.

Being fenced off on all sides, it’s clearly not a natural wilderness, after the land was sold as the interest in tennis declined, nature began to restore the soil but how can we work with nature and help it? By observing nature we can see how all of the different species are interconnected and all play a part. The species at the very bottom of the food chain all support species further up, and yes, we need then to support us too.

The colonization of disturbed ground by pioneering species and the subsequent regeneration of soil is a fascinating and crucial process in ecology. Let’s explore how pioneering species initiate soil regeneration and how ecological succession plays a vital role in restoring ecosystems over time.

What is Ecological Succession?

Ecological succession is the gradual process through which ecosystems change and develop over time. It involves a series of predictable stages in which different species of plants, animals, and microorganisms colonize an area, ultimately leading to the formation of a mature ecosystem, such as a forest or a grassland. Succession can be classified into two types:

Primary Succession:

Occurs on surfaces that have never been colonized before, such as bare rock, volcanic islands, or newly exposed areas after glaciers retreat. In these areas, there is no existing soil, and the process starts from scratch.

Secondary Succession:

Takes place in areas where an ecosystem has been disturbed but where soil and some organisms still remain. Examples include areas affected by wildfires, deforestation, or agricultural abandonment.The process of ecological succession can take years to centuries, and while it may seem slow, it is a vital mechanism that ensures the renewal of ecosystems.

The Role of Pioneering Species

The initial stage of succession, whether in primary or secondary succession, is typically dominated by pioneering species. These are the first organisms to colonize disturbed or barren land. Pioneering species are generally hardy and adapted to survive in harsh conditions where soil may be poor or nonexistent. These species play a crucial role in soil regeneration and ecosystem recovery.

Characteristics of Pioneering Species:

Hardiness: Pioneering species are usually resilient to extreme environmental conditions like drought, heat, and nutrient-poor soil. Examples include mosses, lichens, certain grasses, and small shrubs.

Fast Growth and Reproduction:

They tend to grow quickly, produce large quantities of seeds, and spread rapidly to cover the disturbed area. This helps to establish plant cover quickly, reducing soil erosion.

Soil Formation:

Many pioneering species, such as lichens and mosses, help to break down rock surfaces and contribute organic matter to the soil. Over time, their decaying biomass adds nutrients to the soil, creating a more hospitable environment for other plants.

The Process of Soil Regeneration

Soil regeneration begins as pioneering species establish themselves on the disturbed ground. Their presence leads to the development of the soil layer, which is essential for the survival of other, more complex species.

Here’s how the process works

Lichens and Mosses:

In primary succession, lichens and mosses are often the first organisms to colonize bare rock. They secrete acids that break down rock surfaces into smaller particles, initiating the process of soil formation. As these organisms die and decompose, they add organic material to the surface, enriching the soil with nutrients.

Grasses and Small Plants:

As the soil layer becomes thicker and more stable, grasses and small herbaceous plants begin to take root. These plants are better at stabilizing the soil and preventing erosion. They also help in fixing nitrogen and adding more nutrients to the soil, making it even more suitable for other plant species.

Shrubs and Small Trees:

As soil fertility increases, shrubs and small trees begin to establish themselves. Their roots further enrich the soil, and their leaf litter creates a more complex soil structure, enhancing microbial activity.

Mature Forests:

Over time, the area may develop into a mature ecosystem, such as a forest or grassland, depending on the climate and environmental factors. This final stage of succession typically features a diverse community of plants and animals, with a more complex food web and balanced nutrient cycles.

The Importance of Ecological Succession in Soil Regeneration

Ecological succession and the colonization of disturbed ground by pioneering species play an essential role in restoring soil fertility and ecosystem health. Without this process, ecosystems would struggle to recover after disturbances, leading to degraded landscapes and the loss of biodiversity.

Some of the key benefits of this natural process include:

Soil Fertility:

As pioneering species break down rocks and contribute organic matter, they transform barren landscapes into fertile soils capable of supporting a variety of plants and animals.

Erosion Control:

The early stages of succession help stabilize the soil, preventing erosion by wind and water, which could otherwise degrade the land further.

Biodiversity Restoration:

Ecological succession allows for the gradual restoration of biodiversity. As soil conditions improve, more species can establish themselves, leading to the development of a more complex and resilient ecosystem.

Carbon Sequestration:

The process of soil regeneration and plant growth helps sequester carbon, mitigating the effects of climate change by storing carbon in plant biomass and soil organic matter.

Human Impacts and Assisted Succession

While ecological succession is a natural process, human activities often interfere with it. Deforestation, mining, agriculture, and urbanization can significantly disrupt the land, leaving it barren and severely degraded. In some cases, human intervention is required to help accelerate succession and restore ecosystems.

Assisted succession involves actively managing disturbed areas to speed up natural recovery. This might include activities such as:

Replanting native vegetation:

Introducing native plant species that are adapted to the local environment helps restore the soil and provides a foundation for the return of other species.

Soil amendments:

Adding organic matter or nutrients to the soil can help accelerate soil formation and improve fertility.

Erosion control measures:

Installing barriers, planting cover crops, or using mulch can help prevent further soil degradation and promote plant growth.

Conclusion

The colonization of disturbed ground by pioneering species and the process of ecological succession are vital aspects of soil regeneration and ecosystem recovery. From the first mosses to the eventual arrival of mature forests, succession is a remarkable example of nature’s ability to heal itself. Understanding this process highlights the importance of protecting ecosystems from human-induced disturbances and encourages us to assist in the restoration of degraded lands. As we face increasing environmental challenges, the lessons from ecological succession can inspire more sustainable and effective land management strategies to promote soil health and biodiversity.

The Soil Foodweb