Announce your value-priorities forcefully

A deep ecological movement envisages a shift in basic attitudes from the dominant paradigm in leading industrial societies. Norms and values again and again have to be contrasted, not with any explicit philosophy which justifies the dominant paradigm (that does not seem to exist) but with its practice.

Therefore, we need an elaboration of our norms and values which correspond to the shift of basic attitudes. This requires the tentative systematisation of those norms and values. This is the theoretical background which sets the stage for this chapter, where philosophically problematic topics will be discussed, bearing in mind their importance to practical ecological debate. I will discuss exactly the same subjects in different ways, because readers with diverse backgrounds have been found to require different approaches to the same topics.

Not everything can be proven – an old thought first emphasised by Aristotle. The string of proofs on any definite occasion must commence somewhere. The first unproven links in such chains of argument are called ‘axioms’ or ‘postulates’. Those which are proven by means of these postulates are called ‘theorems’. History of mathematics and logic shows a diversity of systems, but they all have starting points beyond which they do not penetrate. They also have rules, some deduced from other rules, but at least one must be simply postulated, without any justification whatsoever.

When value priorities are traced back to the very fundamentals, the validity of the latter can then be questioned.

In the face of increasing environmental problems, the solutions proposed during the late 60s and early 70s revealed two trends, one in which it was presumed that a piecemeal approach within the established economic, social, and technological framework is adequate, another which called for critical examination of the man–nature relation and basic changes which would affect every aspect of human life. The latter trend, that of the deep ecological movement, involves both concrete decisions in environmental conflicts and abstract guidelines of philosophical character. It is not a mere philosophy of man–nature.

In the previous chapters a large number of problem areas have been touched upon, primarily the technological, economic, and political. Ultimate foundations have also been considered, particularly the contrast between atomistic and gestalt thinking. It remains to go into a number of philosophical issues, and also to touch upon the religious background of man–nature thinking in the West. The treatment will have to be more personal in the sense of leading into particular aspects of my ecosophy, Ecosophy T. But it is not the aim to point to my own particular view in special detail. Much has been already said without explicitly connecting it to the Ecosophy T logical structure. The main goal, as announced in chapter 2, is to emphasise the responsibility of any integrated person to work out his or her reaction to contemporary environmental problems on the basis of a total view.

In previous chapters a variety of theoretical approaches, mainly borrowed from the ecological literature, have been presented. For the most part these formulations have been intended as a framework within which intercrops can be viewed, hoping that some qualitative insights of intercrop dynamics might be revealed in the process. In the present chapter and the one that follows we turn to the practical question of how to use such a theoretical framework in the context of intercrop design.

This problem can be approached in two philosophically distinct ways, as has most of the theory already presented. First is what I call the phenomenological approach, common in the ecological literature, in which the problem is formulated as the quantitative response of one species to varying quantities of a second species. Our concern is simply with the quantitative effect of one species on another, specifically ignoring what might be the underlying causes of that effect. Competition and facilitation are thought of as phenomena worthy of study in their own right, irrespective of the underlying mechanisms that produce the observable competitive or facilitative effects.

The second approach is the mechanistic approach, in which competition and/or facilitation are assumed, but the interest is in the study of the mechanisms that cause them. Thus, competition may be for nitrogen or facilitation may be a consequence of protection from herbivores. The mechanism of overyielding might be the partitioning of the nitrogen environment or the mechanism of facilitation might be disrupting oviposition behavior of a key herbivore.

Weed control is often cited as one of the benefits of intercropping (Moody, 1980; Shetty & Rao, 1979; Unamma et al., 1986; Robinson & Dunham, 1954; Ibgozurike, 1971; Liebman, 1986). The presumed mode of action is that one crop, through competition with the weed, provides an environment of reduced weed biomass for the other crop. An apparent example is presented in Figure 8.1, in which a luxuriant growth of Amaranthus sp. in corn, is dramatically suppressed by a secondary crop of beans. In effect, the beans seem to have been able to replace the Amaranthus completely, and either provide a source of valuable yield, or compete less with the corn than the Amaranthus does.

Perhaps the best-known example is the use of ‘cover crops’, between rows of a monoculture. Liebman (1986) reviewed nine studies involving 23 crop–cover-crop combinations. Of the 23 cases, all but three showed a significant weed suppressive effect.

While the literature on cover crops is impressive, and suggests considerable advantage is to be gained in weed control, the literature on combinations of two crops is less extensive and more equivocal. For example, Ayeni et al. (1984), working in Nigeria, found that a maize–cowpea intercrop failed to significantly suppress weeds in the early cropping season but had a significant effect in the late cropping season. Unamma & Ene (1983) failed to find weed suppression in a cassava–maize system in Nigeria, whereas Soria et al. (1975) found this combination successfully suppressed weeds in Costa Rica.

Introduction

While the focus of this book is on annual crop systems, some of the more common and spectacular examples of intercropping involve perennial crops. Rappaport's classic study of the Tsembaga in New Guinea shows a complex system of succession and intercropping which includes many perennials (Rappaport, 1967). The so-called village forest-gardens in West Java exhibit similar diversity (Michon et al., 1983), as do the compound farms of Nigeria (Okigbo & Lai, 1978). To this day the Maya of Mexico maintain kitchen gardens sometimes growing over 30 species of plants, including fruit trees, bananas, and other perennials, (Alcorn, 1984). In South-East Asia the use of perennials in slash and burn agriculture is well-known (Spencer, 1966).

But it is not only in traditional peasant production that perennials are integral components. Commercial plantations involving intercrops are legion. Coffee and cacao are almost always grown with shade trees (usually a legume), implicitly an intercropping situation, although the production of the shade trees is of no consequence to the producer (Aranguren et al., 1982a, b). But many examples exist of the joint production of two perennials: cacao and coconut (Aggaoili, 1961; Garot & Subadi, 1958; Jose, 1968; Leach, 1971; Traeholt, 1962), coffee and rubber (Townsend et al., 1964), a variety of examples with African oil palm (Sparnaaij, 1957; Webster, 1969; Blencowe, 1969; Soekarno, 1961; Wood, 1966), and at least seven different perennials with coconuts (Nair, 1983).

The foregoing chapters have summarized some of the research directions currently underway in intercropping research and have indicated some possible simple extensions of relatively routine ecological theory into the realm of intercropping research. The ideas expressed have ranged from the mainly intuitive to the highly quantitative engineering designs of intercropping systems, and have utilized some simple applications of set theory and some not so simple applications of partial differential equations. By and large to this point all material has been well-known on two levels, the level of the ecological theory to be applied and the level of the need for it in intercropping.

In this chapter we briefly consider several topics that are either not so well known as ecological formulations and/or not usually part of the typical research agenda of intercropping researchers. These topics are included here because of what appears to be a great need for their consideration among researchers. Because they are topics more for the future than the present, their presentation will be far more tentative and speculative than the rest of the material in the book has been.

Dynamic plant growth and interaction models

A situation in which the need for a dynamic approach is essential was presented in Chapter 10. The use of a static yield–density approach when applied to a system of tomatoes and beans resulted in excellent predictions some of the time.

The basic idea

We begin our exploration of the mechanisms of intercrop advantage by pointing out that one potential mechanism is, in a sense, no mechanism at all. While casual observation leads us to question what causes particular patterns, it is sometimes worthwhile to reflect and ask if the patterns perhaps occur because nothing much is happening. It turns out, as described below, that because of the way we define intercrop advantage, it is quite possible, even perhaps common, to observe an intercrop advantage without anything special happening.

It is easiest to understand this ‘mechanism’ by referring to a similar phenomenon, recognized for many years, in community ecology. It is generally accepted (although the details remain hotly debated) that when two species do similar things (i.e. occupy the same niche, interfere with each other's activities, compete with one another, etc.) it is unlikely that there is enough room in the environment for both. Loosely, two species cannot occupy the same niche. If their niche requirements are sufficiently similar, which is to say they compete with one another intensely, one or the other will become extinct, given a long enough time. On the other hand – and this point is often not emphasized sufficiently – if the two species have similar but distinct requirements, which is to say they compete with one another only weakly, they may both persist indefinitely in the environment.

The book before you is entitled Ecology, community, and lifestyle. It is not a direct translation of Arne Naess' 1976 work, økologi, samfunn, og livsstil, but rather a new work in English, based on the Norwegian, with many sections revised and rewritten by Professor Naess and myself, in an attempt to clarify the original work as well as bring it up to date.

But this is not as straightforward as it might sound. The project involved cornering Professor Naess in between his numerous intercontinental travels, then escaping the problems of busy Oslo to various mountain retreats scattered throughout the country. As the student, I then questioned the professor on the original manuscript, he responded, and together we reworked the manuscript to make it flow smoothly in English and in the 1980s. After being thwarted by blizzards, breaking a ski or two, locking ourselves out of the wood supply by mistake, we finally emerged with the manuscript in its final form.

But even now there is much more we would like to add! In a developing field like ecophilosophy, there can only be an introduction, not a conclusive summary. So we apologise to those who feel key issues may have been left out, and we also apologise to our editors for trying to work too much in. At Cambridge University Press, Dr Robin Pellew, Susan Sternberg, Alan Crowden, and Peter Jackson have all been especially understanding. Daniel Rothenberg provided insightful criticism of the introduction.

The gravity of the situation

Humankind is the first species on earth with the intellectual capacity to limit its numbers consciously and live in an enduring, dynamic equilibrium with other forms of life. Human beings can perceive and care for the diversity of their surroundings. Our biological heritage allows us to delight in this intricate, living diversity. This ability to delight can be further perfected, facilitating a creative interaction with the immediate surroundings.

A global culture of a primarily techno-industrial nature is now encroaching upon all the world's milieux, desecrating living conditions for future generations. We – the responsible participants in this culture – have slowly but surely begun to question whether we truly accept this unique, sinister role we have previously chosen. Our reply is almost unanimously negative.

For the first time in the history of humanity, we stand face to face with a choice imposed upon us because our lackadaisical attitude to the production of things and people has caught up with us. Will we apply a touch of self-discipline and reasonable planning to contribute to the maintenance and development of the richness of life on Earth, or will we fritter away our chances, and leave development to blind forces?

A synopsis of what it is which makes the situation so critical could read:

An exponentially increasing, and partially or totally irreversible environmental deterioration or devastation perpetuated through firmly established ways of production and consumption and a lack of adequate policies regarding human population increase.

We feel our world in crisis. We walk around and sense an emptiness in our way of living and the course which we follow. Immediate, spontaneous experience tells us this: intuition. And not only intuition, but information, speaking of the dangers, comes to us daily in staggering quantities.

How can we respond? Has civilisation simply broken away hopelessly from a perfection of nature? All points to a bleak and negative resignation.

But this is only one kind of intuition – there is also the intuition of joy.

Arne Naess gives a lecture somewhere in Oslo. After an hour he suddenly stops, glances quickly around the stage, and suddenly leaves the podium and approaches a potted plant to his left. He quickly pulls off a leaf, scurries back to the microphone, and gazes sincerely at the audience as he holds the leaf in the light so all can see. ‘You can spend a lifetime contemplating this’, he comments. ‘It is enough. Thank you.’

In 1969, Naess resigned his professorship in philosophy after over thirty years of work in semantics, philosophy of science, and the systematic exposition of the philosophies of Spinoza and Gandhi.

Introduction

In freshwater fish the physiological regulation of the major electrolytes is very sensitive to environmental stressors. Low pH environments in both the laboratory and field cause electrolyte losses in a number of fish species and, indeed, plasma electrolytes have proven to be a fairly reliable indicator of sublethal acid stress (e.g. Leivestad & Muniz, 1976). Similarly, there are now several studies on the toxic trace metals showing that disturbances to ion regulation are either a primary or at least a secondary consequence of exposure to a particular metal. Our objective then is to examine how mixtures of trace metals and H+ might toxically interact to cause ionic disturbances. We have placed emphasis on sublethal effects upon gill function rather than toxicity per se. We first examine the chemical and biological bases for metal and H+ interactions and then present some examples which illustrate the nature of these interactions. It is not our intention to review exhaustively metal and H+ toxicity but rather to point out how one might examine or even predict the interactions of untested metal/H+ mixtures. For a more general and thorough treatment of metal and acid toxicity to aquatic biota the reader is referred to the recent review by Campbell & Stokes (1985).

In terrestrial animals, the toxicity of a particular metal is mainly related to its dose; if a metal is not absorbed then it is not toxic, irrespective of its reactivity in aqueous solution.

Introduction

This paper will review the field and laboratory data on the chemical factors which affect fish and fishery survival in acid waters, and an attempt will be made to relate the two sets of data where this is possible. In general, the field data being considered are predominantly from Norway where the fish species is mainly brown trout, but, where relevant, data from North America will be described. Data from the UK are dealt with by Turnpenny (this volume).

The main chemical factors, other than pH (hydrogen ion concentration) that will be discussed are calcium (hardness) and aluminium concentration. The aquatic chemistry of aluminium, which is generally present in higher concentrations in more acid waters, is complex and it is necessary at this stage to summarise the details on the subject given by Freeman & Everhard (1977), Burrows (1977), Hunter et al. (1980), Spry et al. (1981) and O'Donnell et al. (1983).

Solubility of aluminium is a direct function of ambient pH, being at a minimum at around pH 5.5, and increasing towards both extremes of the pH scale. Soluble cationic species e.g. A13+, A1OH2+ and Al(OH)2+, are formed at pH levels less than 5.5, and soluble aluminate species, e.g. Al(OH)4-, predominate at pH levels greater than 5.5. In natural waters, aluminium has a strong tendency to form complexes with other anions capable of forming coordinate bonds – for example, six different fluoride complexes are known (Burrows, 1977).

Recent advances in modelling plant stands have emphasised the importance of the structural and functional properties of plant canopies, as distinct from those of the constituent parts. In response to proposals made following the 1984 meeting on the ‘control of leaf growth’, which resulted in Seminar Series Publication 27, the Environmental Physiology Group held a series of sessions on plant canopies during the March 1986 meeting of the Society for Experimental Biology at Nottingham. All the invited speakers at these sessions have contributed chapters to this volume either individually or with collaborators.

Chapters have been included on all the major processes occurring in canopies, although there has been space neither for consideration of the manipulation of canopies by chemical or genetical means, nor for discussion of the canopy as habitat for micro-organisms, insects or vertebrates. A policy decision was made at an early stage of planning to encourage authors to look at a diverse range of canopy types and geographical distribution in order to avoid any bias introduced by, for example, considering only temperate zone cereal crops. The reader can decide how successful this policy has been. Some omissions represent genuine areas of ignorance, but it is a matter of regret that space was not available to allow consideration of stands of mixed species either in agricultural intercropping systems or in natural communities.

It is a pleasure to acknowledge the financial and other support of the Environmental Physiology Group, the Association of Applied Biologists and the British Ecological Society.

I would like to record the contributors’ co-operation during the meeting and to thank them for all the time they and their collaborators devoted to preparing and revising their manuscripts.

Introduction

There is some consensus now that the death of many fish species, exposed to acid water, is caused by a chain of events starting with the loss of body electrolytes and eventually leading to osmoregulatory and cardiovascular failure (Muniz & Leivestad, 1980; McDonald & Wood, 1981; McDonald, 1983). Sublethal exposure to acidified water often leads to transient or chronic hypo-osmolarity of the blood plasma, mainly caused by reduced Na+ and Cl- levels (McWilliams, 1980; McDonald, 1983; Wendelaar Bonga, Van der Meij & Flik, 1984a). The severity and duration of these effects are determined by both external and internal factors. External factors, such as the calcium and aluminium concentration of the water and the presence of heavy metals, are dealt with by Wood, Potts & McWilliams, and McDonald et al. (this volume). The rate and degree of change of the environmental pH is also important. Internal factors, in particular hormones, are the subject of this chapter.

The endocrine system is of pre-eminent importance for the control of physiological processes that enable animals to adjust to changes in their environment. Since acidification of the water deeply affects many aspects of fish physiology, pronounced and multiple responses of the endocrine system may be envisaged. When it is taken into account that a predominant deleterious effect of acid water on fish is disturbed water and ion balance, it is not surprising that the hormones with osmoregulatory actions in fish, in particular cortisol, ACTH and prolactin, are given greatest consideration in this chapter. Studies on the effects of acid on fish endocrines are still scarce, and limited to a few species.

Introduction

Most measurements of the effects of acid toxicity on aquatic animals concentrate upon changes in body fluid pH and the flux of ions between water and blood. One problem posed by a low blood pH is the potential acidification of the tissues which could cause undesirable deviation from the optimum pH of intracellular enzymes. This chapter examines the techniques and results of investigations into the regulation of intracellular pH (pHi).

Relatively little is known about pHi in most animals, experiments being so far generally confined to those with large neurones. This is because until recently the only way of following pHi over long periods was with pH-sensitive microelectrodes. This method is still the best, but requires both skill and a large cell. For small cells fluorescent dyes are very promising.

In this chapter I will describe some of the evidence on which the present understanding of pHi regulatory mechanisms in snail, crayfish and leech neurones is based. I will confine this chapter to these preparations because they are reasonably typical, and I lack the space for a full review. I will then consider the effects of external acidification before concluding that maintenance of a constant pHi depends very much on a constant external pH. For a detailed review of intracellular pH, see Roos & Boron (1981), but for shorter and more recent accounts of the subject see Thomas (1984, 1986).