Ecology Textbooks Research Articles

Ecology textbooks revived

Ecology textbooks revived

A Critique of Interspecific Territoriality and Character Convergence

Cody (1969) suggested that species may converge in appearance or voice because similarities increase interspecific aggressiveness, which leads to the individuals of two species maintaining mutually exclusive territories in a common habitat. The advantage of such behavior is that it results in the exclusion of food competitors within the individuals' territories. Thus, according to Cody, interspecific territoriality is adaptive. In 1971 I published an interpretation of observed cases of interspecific territoriality, in which I assumed that interspecific territoriality was aggression that evolved in intraspecific contexts but was misdirected toward individuals of other species which possessed similar features that normally stimulated intraspecific territorial aggression (Murray 1971). I argued that mutual interspecific territoriality is maladaptive for at least one of the species because the subordinate species would eventually be excluded from otherwise optimal habitat, but I did not exclude the possibility of the existence of cases of adaptive interspecific territoriality. The two hypotheses, then, seem contradictory. The first assumes that cases of mutual interspecific territoriality are adaptive, while the second assumes that they are not. Some authors studying birds (Barlow et al. 1970, Brown and Orians 1970, Cheke 1971, Rohwer 1972, 1973, Kroodsma 1973, Emlen et al. 1975), fishes (Myrberg and Thresher 1974), hermit crabs (Hazlett 1972 a, b), and flowers (Levin and Schaal 1970) have found Cody's hypothesis reasonable. It has appeared as an annual review article (Cody 1973) and as a portion of a book (Cody 1974), and has been described in at least two ecology textbooks (Ricklefs 1973, Smith 1974). Because Cody's hypothesis is widely accepted and is contradictory to my own, I wish to examine it and the evidence for it in some detail.

Predators and Prey

O NE OF THE MOST interesting areas of ecology deals with the interaction of predators and prey. The popular media often present these dynamics as though they were a simple outcome of the balance of nature, and the complexities of the interactions are frequently neglected or underemphasized in general biology or ecology textbooks. Most textbooks describe a few experiments on population regulation and perhaps the basic Lotka-Volterra equation model. The prey's escape strategy is usually stressed while the predator's efficiency in prey capture is often ignored. This gives the student only a partial picture. The purpose of this article is to review basic concepts of predator-prey interaction, to encourage the presentation of the predator's role, and to describe a model of predator behavior that I have successfully used for the past two years in an introductory ecology course at Michigan Technological University.

An Advanced Ecology Textbook

EcologyVolume 55, Issue 2 p. 460-461 Review An Advanced Ecology Textbook Kenneth R. Kramm, Search for more papers by this author Kenneth R. Kramm, Search for more papers by this author First published: 01 March 1974 https://doi.org/10.2307/1935240AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume55, Issue2March 1974Pages 460-461 RelatedInformation

Chapter 9: The History of Human Life Expectancy

Many authors have written comparative articles on the history of human mortality and life expectancy; for example, see Acsádi and Nemeskéri (1970), Angel (1969), Brothwell (1971), Gejvall (1960), Genovés (1969), Goldstein (1953), Howells (1960), Kobayashi (1967), Russell (1958), Şenyürek (1951), Todd (1927), Vallois (1937, 1960). These studies are based on skeletal or historical material. Many of these studies have been used as data sources earlier in this work, and in fact several of the same data series are used by many of these authors.Drawing on many of these sources, Deevey (1960) has recently analyzed the history of human life expectancies. This article has been reprinted and cited more than the others combined, and the life expectancies given by Deevey are used in many textbooks of ecology and anthropology. Deevey acknowledges the poorness of his source data, in particular the lack of juvenile skeletons. He also stresses that his life expectancies are only the adult mean ages at death. Yet, since Deevey's values are frequently taken as representative of total life expectancy, it seems appropriate to reexamine them in the light of this work and of material published since his paper. The life expectancies given by Deevey are shown in Table 22.

The Estimation of Oxygen Diffusion Rates in Soils

The importance of soil aeration as a factor in the growth of plants has been acknowledged for a very long time. The early studies were fully reviewed by Clements (1921) and substantial contributions were made later by Cannon and his co-workers (Cannon 1925). A modern, concise review is that of Russell (1952) and the range of its contents underlines the complexity of the interrelationships of aeration and diverse soil factors and root functions. From this complexity stems, in part, the relative neglect of aeration as a topic of research in the past and the scant treatment usually accorded this important subject in textbooks of ecology, plant physiology and soil science. There has also been the difficulty of characterizing aeration in quantitative terms under field conditions. Considering the oxygen aspect of aeration, many investigations have been concerned with nutrient solution cultures and thus have but an indirect bearing on the aeration responses of the plants in the field. Field studies have largely involved the measurement of oxygen concentrations in natural and agricultural soils. Such data, derived from the analysis of collected or withdrawn gas samples, are of limited value, however, since the techniques are incapable of distinguishing micro-environments in the soil. The relevant consideration is the oxygen conditions at the root surfaces, not directly the average concentration in the soil. Specifically, one is concerned with the rate of delivery of oxygen to the roots, that is, with the rate of diffusion. This will be governed in part by the concentration gradient from the soil to the root surface (the resultant of the ambient concentration of oxygen and the rate of consumption of oxygen by the roots) and partly by the impedance offered by the soil to diffusion. Hutchins (1926) and Raney (1949) studied oxygen diffusion into porous chambers buried in the soil. The apparatus is cumbersome for use in the field and, moreover, the absorbers must inevitably be very large compared with the plant roots so that, again, micro-environments cannot be resolved. A method for estimating oxygen diffusion rates in soils has been described by Lemon & Erickson (1952, 1955). The technique is a manual polarographic one

A Revised Edition of a British Ecology Textbook

A Revised Edition of a British Ecology Textbook

Recent Textbooks of Human Ecology

Recent Textbooks of Human Ecology

The Study of Plant Communities

SINCE plant ecology first started, as a distinct division of study within the major science of botany, with the publication of Warming's "Plantes-amfund" in 1895 (first German edition in 1896 and an English edition, "Oeeology of Plants", Oxford, 1909), it has owed much of its rapid growth to American workers. In particular, the concept of succession was clarified and systematized, if not conceived, in the United States, and its development has been stimulated and largely directed by the researches, terminology and theories of American ecologists. It is therefore to be expected that textbooks of ecology intended primarily for American students should record progress periodically. Such works naturally have both peculiar value and particular limitations for students in other countries. They direct attention to points of view and literature which might otherwise be overlooked and to examples which might remain unknown. On the other hand, it is not always easy to evaluate the conclusions reached because of unfamiliarity with both the flora involved and the field conditions. The Study of Plant Communities An Introduction to Plant Ecology. By Prof. Henry J. Oosting. Pp. 389. (San Francisco : W. H. Freeman and Co., 1948.) 4.50 dollars.