Populations, Biocommunities, Ecosystems: A Review of Controversies in Ecological Thinking

The starting point of this essay is that today’s ecological challenges call upon enrichment of the discourse concerning biophysical processes with socially inspired reasoning. I further propose that arguing on the grounds of critical realism (which eclectically borrows methodological items from pragmatism and hermeneutics) may fulfil this task. The specific version of critical realism I outline herewith combines a stratified ontology of bhaskarian origin with an equally stratified epistemology descending from althusserian thinking. At the deeper level lay non-observable mechanisms which produce actual events. At a second level non-observable actual events are generated by the mechanisms laying at the deep domain, while observable experience occurs only at the surface layer. Concerning the stratified scientific practice it starts from ‘Generality I’, i.e. elementary information, knowledge and mental representations, while it also involves first ideas and concepts about the real. Apart from genuine knowledge about the real, at this first step ideological burdens are also embodied. To partially discharge the scientific product from ideology, further scientific practice involves ‘Generality II’, i.e. conceptual tools such as statistics, models, and the like. The final output of this endeavour is termed ‘Generality III’ and consists of a theoretical framework relating to the knowledge of the real world out there. Next, I maintain that the scientific edifice comprises interdependent elements such as the objective of study, the research tools, the theoretical framework and a specific jargon, which shape dialectic wholeness. Then, I describe a stratified scheme including general theories describing the biological universe, partial theories which, within general theories, describe specific ecological worlds, and models at different levels of abstraction. Among these latter, theoretical schemata shape one among the many ecological worlds potentially descending from a partial theory, exploratory tools - foremost simulation models - undertake the task to concretize theoretical schemata and then to explore alternative hypothesis, while the low-level generalizations, i.e. the empirical models carry out the description of the experimental data and statistical testing. Accordingly, I conclude, models occupy an intermediate position bridging theoretical abstracta with experimental data by means of a continuous back-forth movement between the theoretical constructions and raw data, which I compare to the hermeneutic cycle.

Exploring the possibility for eclecticisms between critical realism and various empiricist traditions, I first remark that critical realist insights appear incompatible with positivist thinking mainly because, in accordance with the biological practice, the former aims at the development of coherent ex-post explanatory constructions rather than at the construction of ex-ante explanations relaying on the correspondence with the reality. I further conclude that critical realism on the one hand and pragmatism and hermeneutics on the other belong to diverging mental traditions in that the former keeps strongly on the unity of scientific and everyday ideological meanings, whereas, adhering on dualistic grounds, the latter involve irrevocable distinctions among subject and object, abstract and concrete etc., finally endorsing the idea that theory and praxis belong to different realms. Moreover, critical realism is definitively at odds with the idea of transitive causality which is pertinent to empiricist traditions. I maintain, however, that critical realism, pragmatism and hermeneutics share comparable thoughts relating to the independent existence of the real world out there, while they support the idea of socially mediated scientific explanation. Moreover they share comparable ideas regarding the hermeneutic cycle and the need for pluralistic approaches to the scientific phenomenon. Accordingly, I conclude that careful borrowing of instrumental items may strengthen the explanatory power of critical realism as well as the applicability of realist ideas.

The aim of the present chapter is, through the presentation of a specific case-study, to analyze the dynamic of scientific process, specify the factors that affect it and describe its methodological and conceptual transformations. The concept of “field” was chosen as the unit of study. “Field” is defined as a context of scientific activity consisting of a theoretical core, a subject of research, a vocabulary and research tools.

The focus of the present study is on the field of life history studies and its transformations through time. The specific field was developed during the 1950s, as an attempt to cure the deficiencies of the theoretical framework of population ecology, which rendered research on life history characteristics descriptive and incoherent. The catalyzing factor for the emergence of the field of life history strategies was the interdisciplinary impacts, and especially the impact of neodarwinism. The elaboration of a new theoretical core, also invoking methodological shifts, was the triggering factor for the establishment of the new field.

Until the 1950s, the research tools of the field, such as Lotka’s characteristic equation, focused on density-dependent factors as the factors determining life history strategies. However, questions were soon raised concerning the suitability of such methodologies, especially the mathematical tools. Specifically, the latter were criticized as being unable to describe in a synthetic way the interaction between organism and environment, as well as to embody fundamental concepts like “strategy”.

During late-1960s MacArhtur introduced the model of “r-K selection”, which was the first model providing results concerning the life history strategy of an organism. It also succeeded in describing a mechanism of natural selection determining life history strategies. The worldview embedded in the “r-K selection” model is characterized by determinism, equilibrium and homogeneity, while its approach remained largely reductionistic. The abiotic factors, as well as the dynamic nature of the organismenvironment relationship were in fact not taken into consideration.

Within the framework of habitat templets models introduced in mid-1970s, the focus of research shifted towards environmental causal factors, considering density-dependent phenomena as by-products of the environmental impact. That implied an important shift in causality as well as in the worldview of life history theorists: population was no longer considered as a closed system isolated from the environment. Methodological changes were also important: The theoretical framework of the field combined holistic and reductionistic insights, using a variety of heuristic models. This imposed a new conception of generality as well as of the structure of scientific theories.

This chapter is a brief contribution to a very long discussion in the history and philosophy of science, the holism/reductionism debate. My aim is not to adhere to the commonly perceived view of ecology as being straightforwardly divided in two competing camps, a holistic ecosystem approach and a reductionistic population ecology. Rather I suggest that ecological research has never mapped comfortably onto this dualism. Hence, I turn to the discipline’s formative years, roughly up to the mid- 1960s, and follow the contributions that gave the debate its special flavour. It soon becomes evident that, at least during the first decades of the twentieth century, the holistic perspective was influenced by Frederic Clements’ organismic approach, while reductionism was attached to Henry Gleason’s individualistic concept. The works of Arthur Tansley, Raymond Lindeman, Eugene and Howard Odum were fundamental in the development of a vigorous systemic-holistic approach. Population ecology, on the other hand, appears much less reductionistic than often considered as the holistic current deeply affected most of its forerunners like Alfred Lotka, Raymond Pearl and Alexander Nicholson. The proposed distinction becomes blurrier when one considers the ecosystem studies methodology. As it is often implied the Odumian approach to ecosystems, despite its holistic parlance, was actually a form of large-scale reductionism. More to the point, I suggest that a mechanistic view of nature, the search for a fundamental methodological level and physics-envy are characteristics of both the holistic and reductionistic perspective in ecology. However, the existence of these dominant schools of thought is, nowadays, a caricature since most ecologists work in one frame or the other without adhering to extreme metaphysical claims. Nevertheless, the discomfort with accepting mere eclecticism has led me to consider Richad Levins and Richard Lewontin’s dialectical approach. Their writings offer deep insight concerning the relation between parts and wholes, properties of parts in respect to their contextual whole, and the causal relation between contextually defined parts and the contextual whole of which they are parts. What I consider of paramount importance for the actual concerns and practices of ecologists is the conscious, pragmatic pluralism stemming out of their view.

Systems ecology in the style of Howard Odum was the prevailing ecological field in the period 1950-1970 and declined afterwards. Nevertheless, in 1992, three outstanding system ecologists, Bernard Patten, Sven Eric Jørgensen and Milan Straškraba began publishing a series of papers in which they attempted to introduce some new perspectives on ecosystems and make systems ecology flourish again.

The work hypothesis of this essay is that Patten and coworkers would have a better fate than their precursors, if their approach to ecosystems enabled the systems ecology to face both the past internal anomalies and the social incompatibilities. To test this hypothesis, I am searching for how they handle the old worrying problems related to the field’s hallmark, namely holism. As a matter of fact, Patten and coworkers rather spontaneously borrowed conceptual resources from the domain of social network theories such as Actor-Network theory and make it possible for systems ecology to cope with the failure of Howard Odum a) to define ecosystem boundaries as naturally existing b) to treat the ecosystem as a biological and not as a physicochemical entity and c) to offer a unified but pluralistic framework for studying ecological entities. While the innovations introduced configure problem-solving strategies, Patten and coworkers avoid dislocating the former structure. The latent ideological assumptions of the old field are not questioned and the beneficial potential of the innovations is not activated. Patten and coworkers interpret innovations from a viewpoint overarched by scientific romanticism and the technocratic worldview, a matter that inevitably brings back the old problems and prevents the field from harmonizing itself with the contemporary and prevailing social ideas and ideals.

Despite the mounting discussions on the concepts of diversity and biodiversity, no generally accepted definition has ever emerged, while many ecologists have argued that the concept of diversity lacks ecological meaning. The ambiguity of diversity is interpreted here as the result of hidden, socially originated, ideological representations within the scientific fields of ecology. Ideological representations are discerned since the first appearance of diversity indices in the early 1940’s. The index of diversity was first introduced in ecology as a simple statistical constant within the equations of species-individuals curves, expressing the equitability with which individuals are distributed into different species. Distribution models presuppose that individuals be distributed into different species in a regular, repeatable way that expresses the hidden, internal order of every biological community. This presupposition is attributed to the ideological influence of organicism, according to which biological communities used to be considered as stable, discernible, harmonically and hierarchically organized unities of members.

However, soon after their introduction, species-individuals equations were automatically reversed and diversity became the variable under question. Hence, the measurement of diversity arose as the central question and ecologists employed new methods and concepts from Statistics, Systematics and Information Theory in order to find appropriate indices of diversity. Diversity indices, as quantified expressions of biological complexity, embody an infinite series of material qualities -such as individuals, populations, species and interspecies relationships- which under the frame of a mathematical function are equalized as general equivalents. It will be argued that the emergence of diversity indices through a reification process is motivated by hidden ideological representations reflecting dominant socioeconomic practices.

After the 1950’s diversity indices were employed by the uprising field of Systems Ecology. Diversity was related to other important ecosystem’s properties, such as stability, productivity and efficiency. Under the premises of an arising ecological crisis, ecologists tried to establish a positive correlation between diversity and stability, due to an external, social pressure for appropriate criteria of ecosystem management. Nevertheless, through this socially motivated relation, the meaning of ecological stability is redefined as the lack of fluctuation, acquiring a cybernetic, quantified aspect. Similar arguments are held with regard to the relation between diversity and productivity or efficiency. Finally, a complex of correlated, quantified, measurable and manageable ecosystemic concepts is emerging from the older fields of community and ecosystem ecology, leading to the new unifying attempts of the late 1960’s and to the new scientific-political field of environmental management. In this process, diversity arises as the nodal point of its field, a concept that transforms and determines the meaning of all others, due to its socially originated power.