Academic Ecology Research Articles

The role of harvesting in age-structured populations: Disentangling dynamic and age truncation effects

Understanding the processes generating fluctuations of natural populations lies at the very heart of academic ecology. It is also very important for applications such as fisheries management and pest control. We are interested in the effect of harvesting on population fluctuations and for that purpose we develop and analyze an age-structured model where recruitment is a stochastic process and the adult segment of the population is harvested. When a constant annual harvest is taken the coefficient of variation of the adult population increases for most parameter values due to the age truncation effect, i.e. an increased variability in a juvenescent population due to the removal of older individuals. However, if a constant proportion of the adults is harvested the age truncation effect is sometimes counteracted by a stabilizing dynamic effect of harvesting. Depending on parameter values mirroring different life histories, proportional harvest can either increase or decrease the relative fluctuations of an exploited population. When there is a demographic Allee effect the ratio of juveniles to adults may actually decrease with harvesting. We conclude that, depending on life history and harvest strategy, harvesting can either reinforce or dampen population fluctuations due to the relative importance of stabilizing dynamic effects and the age truncation effect. The strength of the latter is highly dependent on the fished population’s endogenous, age-structured dynamics. More specifically, we predict that populations with strong and positively autocorrelated dynamics will show stronger age truncation effect, a testable prediction that offers a simple rule-of-thumb assessment of a population’s vulnerability to exploitation.

Sustainability research and practices in enforced residential institutions: collaborations of ecologists and prisoners

Enforced institutional settings such as penitentiaries provide environments to raise awareness, carry out research, and implement and assess practices for sustainable living. Institutions where residence is enforced due to health, recreational, military, or legal reasons (e.g., assisted living centers, summer camps, army bases, prisons) house people who may lack scientific training but have time and need for intellectual stimulation that can be filled by supervised research. These institutions have stable populations, structured social organization, and measurable inputs and outputs of materials and energy to carry out sustainable practices in tasks that affect regional resources such as groundwater quality and landfill use. We report on three examples at a corrections center resulting from partnerships among visiting academic ecology researchers, sustainability practitioners, corrections administrators, and prisoners: (1) research on how to sustainably “farm” moss for the horticulture trade to reduce harvesting pressure on wild moss populations; (2) a vermiculture and thermophilic composting system to reduce the kitchen waste; and (3) a monthly seminar series at the prison. Over 26 months: (1) participants developed methods to optimize moss growth; (2) landfill-bound waste and particulate flow rate destined for wastewater treatment decreased by 50%, to less than 50% of permit limits; (3) resulting compost (ca. 5000 kg) fertilized institutional vegetable gardens; (4) water quality improved so that the prison could return funds allocated to upgrade the prison’s water quality. The lectures encouraged intellectual exchange among researchers, convicts, and guards. Researchers derived new perspectives and broader impacts for their work. This can be a model for other correctional facilities and other enforced residential institutions (ERIs).

The Changing Academic Ecology of Sociology: Learning to Live With More Frogs in the Pond

Sociology exists in a dynamic academic environment that influences how students view and evaluate the discipline. This essay explores the changing academic context of sociology through the author’s experience as a professor and department chair over a span of four decades. Increased co-curricular programming, changing student goals, and more competitive disciplinary neighbors present sociology departments with new challenges in attracting students. Central to these challenges is the erosion of sociology’s once distinctive niche in the academic ecology. Questions and suggestions are explored regarding adaptive strategies that might enable sociology to find a niche wherein it can thrive.

Traveling theory, or, transforming theory: Metamorphosis of postcolonialism in China

Since the end of the 1980s, when the term “postcolonial” first landed mainland China, postcolonialism or postcolonial theory has been vigorously traveling in China for nearly twenty years. From 1995 to 1999, postcolonial criticism prospered and aroused several consequential issues such as the problem of “aphasia” of Chinese literary theories and its reconstruction, “Postism” and its conservatism, cultural self-colonization phenomena, “the third world culture,” nationalism and the so-called “Chineseness” and so on. The articles and books published during the period witness the highest achievement of postcolonial criticism in China. But the hasty traveling of postcolonialism in China has elicited or exposed many serious problems in the circles of literary criticism and literary theories. Unhealthy academic ecology in China combined with the misappropriation of the Western source texts, provoking heated debates over nationalism, “Chineseness,” “aphasia” and intellectual responsibility. Through analyzing these complicated issues, the author intends to present his own understanding of the traveling and metamorphosis of postcolonial theories in the Chinese context, and to offer his critical reflections on the problem of how to borrow theories from abroad.

Natural History: the sense of wonder, creativity and progress in ecology

This essay addresses the question of blending natural history and ecological wisdom into the genuine creativity exemplified by Prof. Ramon Margalef. Many have observed that modern biology is a triumph of precision over accuracy, and that ecology has sought maturity by striving toward this model in which the precision value of the tools has supplanted important questions. In pursuing a model of hard science, ecology has struggled with Popperian approaches designed to create a thin patina of real science over the vast seas of uncertainty so admired by the naturalists. We start with a discussion of the importance of natural history in ecology and conservation, and the present state of natural history in academic ecology. We then discuss the respect for natural history in human cultures, and conclude that an infatuation with authority has obfuscated the important truths to be found in nature. We consider some general processes associated with creativity, and finally we ask how natural history influences creativity in ecology. We conclude that the soaring creativity exemplified by Ramon Margalef is based on a joyful almost spiritual understanding of natural history and the courage to avoid authority.

Landscape ecology practice by small scale river conservation groups

River–floodplain systems, and riparian forests in particular, offer physical contributions to human society such as flood mitigation and the maintenance of water quality, social benefits including the opportunity for recreation and solitude, as well as numerous ecological services. However, midwestern USA river landscapes have undergone much land-use change over time, such as widespread logging, the net loss of grasslands and wetlands, urbanization pressure, and increases in anthropogenic sedimentation. With its focus on spatial and temporal changes, landscape ecology is ideally suited to assess and quantify these riverlands modifications and it is currently used at the national, state, and sub-state level in efforts to restore or manage river and riparian landscapes. This two-part study explores the use of landscape ecology in smaller scale river conservation. First, we interviewed five locally-based, Midwestern non-profit conservation groups that were accomplishing significant river conservation and management work without intricate ecological plans. We found a tacit knowledge of fundamental landscape ecology concepts, and active interpretation to fit particular environmental situations. The groups were receptive to increased assistance from academic ecology, but the content must be clear, succinct, and easily integrated into frontline initiatives. To accomplish this goal, effort is needed from ecologists to construct new methods of delivering such information in an accessible and cost-effective manner. Second, we briefly explore land-use scenarios — based on realistic forest management agendas along the Wisconsin River (USA) — as one possible means of using applied science to assist local conservation efforts in prioritization of land parcels. Various land management scenarios to reinstate floodplain forest often produced similar improvements in metrics of landscape connectivity but differed markedly in the number of landowners affected.

Is there a special conservation biology?

Conservation biology is special to the extent that it fills useful roles in the scientific and conservation fields that are not being filled by practitioners of other disciplines. The emergence of the “new conservation biology” in the late 1970's and its blossoming in the 1980's and 1990's reflect, to a large degree, a failure of traditional academic ecology and the natural resource disciplines to address modern conservation problems adequately. Yet, to be successful conservation biology, as an interdisciplinary field, must build on the strengths of other disciplines both basic and applied. The new conservation biology grew out of concern over extinction of species, although the field has expanded to include issues about management of several levels of biological organization. I examine four controversial questions of importance to conservation biologists today: 1) are there any robust principles of conservation biology? 2) Is advocacy an appropriate activity of conservation biologists? 3) Are we educating conservation biologists properly? 4) Is conservation biology distinct from other biological and resource management disciplines? I answer three of these questions with a tentative “yes” and one (3) with a regretful “in most cases, no.” I see a need for broader Training for students of conservation biology, more emphasis on collecting basic field data, compelling applications of conservation biology to real problems, increased influence on policy, and expansion of the international scope of the discipline. If all these occur, conservation biology will by truly special.

Microcosms as Models for Generating and Testing Community Theory

EcologyVolume 77, Issue 3 p. 670-677 Article Microcosms as Models for Generating and Testing Community Theory James A. Drake, James A. DrakeSearch for more papers by this authorGary R. Huxel, Gary R. HuxelSearch for more papers by this authorChad L. Hewitt, Chad L. HewittSearch for more papers by this author James A. Drake, James A. DrakeSearch for more papers by this authorGary R. Huxel, Gary R. HuxelSearch for more papers by this authorChad L. Hewitt, Chad L. HewittSearch for more papers by this author First published: 01 April 1996 https://doi.org/10.2307/2265489Citations: 89AboutPDF 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 onFacebookTwitterLinked InRedditWechat Citing Literature Volume77, Issue3April 1996Pages 670-677 RelatedInformation

An idiosyncratic assessment of the role of mathematical models in environmental sciences

This paper summarizes a number of studies in two disciplines of particular interest to environmental scientists and managers: academic ecology and academic economics. These studies suggest that too often in the past we have been extremely cavalier in our acceptance and use of some theoretical mathematical models purporting great importance and generality. Of particular concern is that on a number of occasions, data have been presented as substantiation of certain theoretical models while in fact, on closer examination, they are not. In many cases, the use of these formulations have led to unnecessary environmental destruction and illogical economic decisions. I conclude that, although there are many good reasons to continue to formalize our knowledge about systems through explicit model development, we must not continue to confuse mathematical rigor with scientific rigor, and we must subject our theoretical formulations to more rigid tests vis-a-vis nature than we have in the past.

The Biological Control of Weeds

The biological control of weeds is intimately connected with basic eco­ logical problems, and its interest extends far beyond practical considerations. All attempts at the biological control of weeds are field experiments of the greatest ecological interest. The scope of this research is extensive and com­ plex, and workers engaged on these problems have had to lead the way in some important respects rather than lean on academic ecology. Nevertheless, there has been a considerable measure of agreement among the different writers on the subject, though there are points of difference and variations in emphasis. Thc litcrature, already voluminous, was reviewed in this series of Annual Reviews as recently as 1959 by Huffaker (37), who, among other valuable contributions he has made, has examined the fundamentals of the subject in an important paper (35). The present writer's views were expressed in earlier papers (71-77). In view of past examinations of the matter, and of the general body of agreement that exists, it would be repetitious to review here all the literature and all important aspects of the subject. Instead, it is intended to discuss a limited number of topics of particular current interest, and to refer briefly to recent developments in individual weed problems.

Academic ecology: On the location of Institutions of Higher Education

Academic ecology: On the location of Institutions of Higher Education