The world is facing an ecological crisis, and our understanding of ecosystems and their functions is crucial in addressing these challenges. But what if our very concept of ecosystem function is flawed? This article delves into the philosophical and scientific underpinnings of this question, exploring how our perceptions shape our responses to environmental issues.
The Problem with Purpose
Ecosystems, unlike machines, do not have inherent goals or purposes. The Amazon rainforest, for instance, doesn't aim to absorb carbon; it just does so as a natural process. Yet, we often attribute functions to ecosystems, projecting our desires onto nature. This anthropocentric view raises concerns about our ability to truly understand and address ecological crises.
A Historical Perspective
The concept of ecosystem function has evolved over time. In the 19th century, conservation efforts were rooted in game laws and hunting traditions, focusing on maintaining certain species. Later, Aldo Leopold expanded this view, proposing that our moral community should include 'the land' itself. This shift led to a focus on intrinsic species value, as seen in the US Endangered Species Act.
However, in the late 20th century, a new approach emerged: biodiversity and ecosystem function (BEF). This paradigm shift emphasized the services ecosystems provide to humans, from food production to climate regulation. The language of ecosystem function became a powerful tool to justify conservation, but it also introduced a teleological perspective that some argue is conceptually shaky.
Theories of Function
Two main theories guide our understanding of function: causal role theory and selected effects theory. Causal role theory, developed by Robert Cummins, focuses on an object's contribution to the system it's part of. This theory is attractive to ecologists interested in tracing causal chains. However, it struggles to distinguish genuine functions from incidental effects and cannot explain malfunction.
Selected effects theory, on the other hand, anchors function in evolutionary history. It states that a trait's function is the effect for which it was selected during natural selection. This theory provides a standard for success and failure, which is crucial when considering ecosystem function.
The Challenge of Ecosystem Function
The concept of ecosystem function becomes problematic when applied to systems like rainforests or coral reefs, which have effects we can describe but no clear ends. Frederic Clements' early 20th-century view of ecosystems as developing towards a stable climax community has been abandoned. Modern ecologists see ecosystems as open, dynamic systems, composed of countless interactions, with no intrinsic trajectory or unified purpose.
Yet, the language of function persists. Wetlands 'function' to filter water, and forests 'function' as carbon sinks. This descriptive use of 'function' often merges with goal-directed judgments, blurring the line between description and prescription.
The Political Work of Metaphor
Metaphors like Paul Ehrlich's 'rivet popper' analogy, comparing species loss to losing rivets from an airplane wing, have been powerful tools in environmental advocacy. They make the stakes of biodiversity loss vivid and align neatly with the ecosystem services agenda. However, these metaphors also carry anthropocentric assumptions, suggesting that ecosystems have a proper configuration and that deviation is a malfunction.
Malfunction and Human Values
Ecosystems can only malfunction when they are appropriated or co-opted for human-defined goals. A wetland's ability to filter water or a forest's carbon storage capacity can be seen as functions that can malfunction when these processes are disrupted. These 'malfunctions' reflect human values and priorities, framing nature's worth in terms of utility, aesthetics, or cultural and spiritual value.
Moving Beyond Teleology
To move beyond teleological descriptions, ecologists could focus on characterizing interactions and quantifying changes of state without referring to purposes. This approach respects the autonomy of the non-human world while avoiding the imposition of human values. However, even this objective stance is shaped by human values, as Bas van Fraassen argues in 'The Empirical Stance'.
The Way Forward
Recognizing the role of human values in scientific practice is crucial. When we say natural systems exist to provide services for us, we are appropriating certain processes for our own purposes. This active privileging of certain ecological processes over others is a choice, not a natural fact. By being explicit about our values and needs, we can develop a more rigorous and reflective ecology, joining scientific description with moral responsibility.
The work ahead is not about repairing nature's purposes, which it doesn't have, but about taking responsibility for our own purposes and the world we shape through them.
