Ecological succession & soil building

Ecological succession and soil building as an ecosystem transformation process 

Understanding ecological succession 

Ecological succession is a natural phenomenon, where ecosystems undergo systematic and predictable changes over time. This dynamic process involves the gradually transforming species composition, structure, and environmental conditions within a specific habitat. Each successive community creates certain habitat conditions that pave the way for the next group of organisms to establish themselves. 

The stages of ecosystem development 

1. Community progression 

Each ecological community creates unique environmental conditions that prepare the ground for subsequent communities. This intricate process is like a complex ecological relay race, where one group of organisms sets the stage for the next.  

Primary succession begins in the most challenging environments imaginable - on completely bare surfaces like newly formed volcanic landscapes, retreating glacial areas, exposed rock formations, or freshly created land masses. 

Secondary succession occurs in areas that previously supported life but experienced significant disruption. This process can occur on abandoned agricultural lands, post-wildfire landscapes, deforested regions, or areas recovering from natural disasters. 

2. Soil formation dynamics 

As communities develop, the decomposition of biomass plays a crucial role in soil formation. Organic matter breaks down, enriching the soil with nutrients and creating a more hospitable environment for increasingly complex life forms.  

This includes processes such as: 

• Physical environment modification- soil structure alteration, microclimate changes, and nutrient profile development. 

• Biological interaction enhancement- competitive species replacement, establishment of symbiotic relationships, and increase in ecosystem complexity. 

• Nutrient cycling improvement- organic matter decomposition, mineral nutrient release, soil fertility enhancement. 

3. Attained climax community 

• Nutrient accumulation and stability: 

As mature soil develops and nutrient availability increases, ecosystems progress towards a climax community - a stable, well-balanced ecosystem like a mature forest. This represents the pinnacle of ecological development for a particular location. 

• Ecosystem resilience: 

A climax community maintains its structure and composition until significant disturbances interrupt its equilibrium. These disturbances could include natural events like fires, storms, or human interventions. 

The critical role of microbiomes 

Microbiome consortia are fundamental to this ecological transformation. These microscopic communities play a critical and often overlooked role in driving ecological succession, fundamentally reshaping environments through complex interactions and metabolic processes. Different ecosystems showcase unique microbial compositions that reflect their developmental stage and environmental conditions. 

Microbial diversity across landscapes 

• Agricultural soils:  

Regularly tilled areas have a bacteria-dominant microbiome because they better tolerate mechanical disturbances. Fungi are represented in a smaller proportion due to frequent tilling. 

• Grassland ecosystems:  

These areas demonstrate a more balanced distribution between bacteria and fungi. It provides complex root zone interactions. High microbial diversity supports grassland stability. 

• Forest environments:  

Fungal biomass significantly outweighs bacterial populations, reflecting the complex Extensive mycelial networks underground networks supporting forest ecosystems. It is responsible for complex decomposition processes. 

Agricultural intensification and soil health 

Modern agricultural practices have often disrupted natural soil formation processes. Intensive farming can decrease soil organic carbon (SOC) and interrupt natural nutrient cycling in soil. However, by implementing regenerative farming practices that recognize soil as a living, complex ecosystem, we can transition from extractive to regenerative agricultural practices by minimizing soil disturbance and supporting natural ecological processes. 

Conclusion and future perspectives

Ecological succession reminds us of the intricate, interconnected nature of ecosystems. By understanding these processes, we can develop more sustainable approaches to land management and conservation. 

By understanding and supporting ecological succession, we can transition from extractive, destructive practices to regenerative strategies.

Source: Image: following stages of secondary succession (top; 1), soil cores demonstrating a development of a litter and humus layer on sandy soil in regenerating boreal forest after clearance for agriculture (bottom; 2) [credits: 1 - Permaculture Apprentice; 2 -Beth Evans].