Ecosystem Stability and Functioning

Whether ecosystems resist and recover from disturbance, and how their biodiversity supports the processes that sustain them, are central questions for understanding a changing world.

Definition

Ecosystem stability and functioning concern the capacity of an ecosystem to maintain its processes and recover from disturbance, and how the diversity and traits of its organisms govern those processes.

Scope

This topic covers the stability, resilience, and functioning of ecosystems: the distinction between resistance, resilience, and engineering versus ecological stability; the relationship between biodiversity and ecosystem functioning; functional traits and redundancy; alternative stable states and regime shifts; and the delivery of ecosystem services. It treats how diversity influences productivity and stability and how ecosystems respond to perturbation.

Core questions

• What do resistance and resilience mean for ecosystems?
• How does biodiversity influence ecosystem productivity and stability?
• What are alternative stable states and regime shifts?
• How do ecosystems deliver the services that humans depend on?

Key theories

Resilience and alternative stable states

Holling distinguished resilience—the ability to absorb disturbance and reorganise while retaining function—from local stability, and showed that ecosystems can possess multiple stable states separated by thresholds across which they can abruptly shift.

Biodiversity and ecosystem functioning

Experiments show that greater species and functional diversity tends to increase productivity and stabilise ecosystem processes through complementarity and insurance effects, though the strength of the relationship varies.

Mechanisms

Stability arises from how an ecosystem responds to perturbation: resistance is the degree to which processes remain unchanged, while resilience is the rate and capacity of recovery. Diversity can enhance functioning when species use resources in complementary ways or when some are more productive, and can stabilise aggregate properties through the insurance effect, whereby a varied set of species buffers function as conditions change. Strong nonlinear feedbacks can create thresholds where a small added stress flips the system into a contrasting state that resists return.

Clinical relevance

These concepts underpin the valuation and management of ecosystem services, the assessment of how biodiversity loss threatens ecosystem reliability, and the anticipation of regime shifts such as lake eutrophication or coral reef collapse. This is educational context, not management prescription.

History

A long debate over whether complexity begets stability was reframed by May's theoretical work in the 1970s and Holling's resilience concept in 1973. Biodiversity-ecosystem-function experiments led by Tilman, Naeem, and others in the 1990s brought the question into the field, and resilience thinking grew into a framework for managing social-ecological systems.

Debates

Does diversity beget stability?

Whether more diverse ecosystems are inherently more stable was contested after May showed that random complex systems can be less stable; reconciling theory with experiments that find diversity stabilises aggregate function remains an active area.

Key figures

• C. S. Holling
• Robert May
• David Tilman
• Shahid Naeem

Seminal works

• holling1973
• tilman1997
• chapin2011

Frequently asked questions

What is the difference between resistance and resilience?

Resistance is how much an ecosystem stays unchanged when disturbed, while resilience is how quickly and fully it recovers afterward; an ecosystem can be high in one and low in the other.

What is a regime shift?

A regime shift is an abrupt, often persistent reorganisation of an ecosystem into a different state, such as a clear lake turning turbid, that occurs when a threshold is crossed and is difficult to reverse.