Daniel Janzen
From Wikipedia, the free encyclopedia
Daniel Hunt Janzen (born 1939 in Milwaukee, Wisconsin, U.S.) is an evolutionary ecologist, naturalist, and conservationist. He divides his time between his professorship in biology at the University of Pennsylvania (Philadelphia, USA), where he has been since 1976, and his research and field work in Costa Rica, where he is an ad honorem (without remuneration) technical advisor for two long-term and long-range projects, which he conceived and initiated in the early 1970s: Area de Conservación Guanacaste, probably the oldest, largest and most successful habitat restoration project in the world, 1.430 km², located just south of the Costa Rica-Nicaragua border, between the Pacific Ocean and the Cordillera de Tilaran; and the Instituto Nacional de Biodiversidad (INBio), a research organisation that has taken the task of inventorying, cataloguing and describing the country's gigantic natural endowment.
Janzen obtained his B.Sc. degree from the University of Minnesota, Minneapolis in 1961, and his Ph.D. from the University of California, Berkeley, in 1965. In 1964 he attended as a student a two-month course in tropical biology taught in several field sites throughout Costa Rica, offered by the Organization for Tropical Studies (OTS), a consortium of several North American and Costa Rican universities. He went back in 1965 as an instructor and has lectured in at least one of the three yearly courses every year since. Before joining the faculty at the University of Pennsylvania he taught at the University of Kansas (1965–1968), the University of Chicago (1969–1972) and at the University of Michigan (1972–1976). Janzen has also held teaching positions in Venezuela (Universidad de Oriente, Cumaná in 1965-66; Universidad de los Los Andes, Mérida in 1973), and in Puerto Rico (Universidad de Puerto Rico, Río Piedras, 1969). From these teaching positions, because of his continuous association with OTS, through his numerous publications and mostly from his exemplary dedication, Janzen has been in close contact and influenced the thinking and ideas of just about every researcher and student of tropical ecology and conservation in the western hemisphere during the last 40 years.
Contents |
[edit] Research, from theory to praxis and back to theory
Janzen's work exemplifies the dialectic method of research applied to the biology of the natural world. For him it has not been the passive analysis of documents and data about ecological processes in order to formulate theories, but rather the active creation of life size scenarios of ecological change and their careful and meticulous documentation from which he then formulates theories which inspire new grand experiments in an ever expanding spiral of knowledge based on the keen observation of nature. The following three sections are an attempt to synthesise the three main themes of his lifelong quest and work.
[edit] Coevolution of plants and animals
[In preparation]
- Coevolution of a mutualistic system in New World tropics between species of Acacia (Mimosoideae; Leguminosae), v. gr., Acacia cornigera, and the ant Pseudomyrmex ferruginea (Formicidae). Acacia spp in the Neotropics are protected by ants against defoliation; for this, the ants are rewarded by means of special organs and physiology that Acacia has evolved. Also Cecropia spp, different plant, different ant, same story! 1
- Spondias mombin (Anacardiaceae) lost its megafauna seed dispersors in the Pleistocene. Between fire in open pastures and seed predation by brochid beetles in closed-canopy forest, S. mombindoes not stand a chance. But, today, in Guanacaste, seeds are dispersed by White-tailed deer (Odocoileus virginianus) and some 15 other mammals, that feed mostly in forest edges, where bruchids are less likely to find the seeds and fires are not so frequent. 2
[edit] Tropical habitat restoration
[In preparation]
Tropical dry forests are the world most threatened of forest ecosystems. In middle America there were 550.000 km² of dry forests at the beginning of the 16th century; today, less than 0,08% (440 km² ) remains, they have been cleared, burnt and replaced by pastures for cattle raising, at an ever faster rate during the last 500 years. However, beginning in the early 1970s, Janzen dreamed a most fantastic project, to grow back some 700 km² of natural, pre-Colombian habitat in Guanacaste, in order to integrate four different national parks which together house at least 15 different biotopes, (mangroves, dry forest and shrubs, ephemeral, rainy season, and permanent streams, fresh water and littoral swamps, evergreen rain- and cloud forests…) and ca. 4% from world's plant, mammals, birds, reptiles, amphibians, fishes and insects diversity, all within an area less than 1.500 km². This is Área de Conservación Guanacaste (ACG). 3
Habitat restoration is not a simple matter, not only one should fight against hundreds of years of ecological degradation, manifested in the form of altered drainage patterns, hard to eradicate pastures, compacted soils, exhausted seed banks, diminished adult and propagule stocks, proliferation of fire-resistant and unpalatable weeds from the old world tropics and sub-tropics, et cetera, but also one should face the difficulties of changing a culture which coevolved with, profited from and can become miserable with such a system. For this reason ACG was conceived as a cultural restoration project as well, which, to paraphrase its natural counterpart, ought to be grown as well. ACG rests on three complementary processes that integrate experimentation, habitat restoration and cultural development, to speed up succession:
- Active restoration, artificial dispersal of propagules from plant species native to the Guanacaste habitats
- Passive restoration by means of fire, poaching and hervivory control
- Ecological education and sensibilisation
[edit] Sustainable ecosystem utilisation
[In preparation]
Agriculture in the tropics - "Tropical Agroecosystems," Science, 1973, paper.
[edit] Honorary distinctions
Janzen has been subject to recognition many times in the USA, as well as in Europe and Latin America; the monetary endowments of these prizes have been invested in the trust fund of the ACG or another of his conservation's projects in Costa Rica; amongst the 19 prizes and distinctions, the following are the most important:
- 1975 Gleason Award, American Botanical Society
- 1984 Crafoord Prize: Coevolutionary ecology. Swedish Royal Academy of Sciences
- 1985 Distinguished Teaching Award, University of Pennsylvania
- 1987 The Berkeley Citation for Distinguished Achievement and Notable Service to the university
- 1987 Hijo Ilustre de Guanacaste (awarded by the Governor of Guanacaste province)
- 1987 "Global 500" Roll of Honour, UNEP
- 1989 MacArthur Fellowship
- 1989 Joseph Leidy Medal, Philadelphia Academy of Natural Sciences
- 1991 Founder's Council Award of Merit, Field Museum of Natural History
- 1992 Member, National Academy of Sciences, USA
- 1993 Award for Improvement of Costa Rican Quality of Life, Universidad de Costa Rica (co award with W. Hallwachs).
- 1994 Silver Medal Award, International Society of Chemical Ecology.
- 1995 Conservation Society Award.
- 1996 Honorary Doctor of Science, University of Minnesota.
- 1996 Thomas G. and Louise E. DiMaura Endowed Term Chair, University of Pennsylvania
- 1997 Kyoto Prize (Basic Sciences Field), Inimori Foundation
- 2002 Albert Einstein World Award for Science, Consejo Cultural Mundial, (Mexico)
[edit] Publications
[In preparation]
More than 300 papers mostly on tropical habitats and organisms.
[edit] References
- Janzen, D. H. 1966. Coevolution of mutualism between ants and acacias in Central America. Evolution: 20(3) 249-275
- Janzen, D. H. 1985. Spondias mombin is Culturally Deprived in Megafauna-Free Forest. Journal of Tropical Ecology 1:131–155.
- Janzen, D. H. 1986. Guanacaste National Park: Tropical Ecological and Cultural Restoration. Editorial Universidad Estatal a Distancia/ FundaciónTinker/Fundación Parque Nacionales/103 pp. San José, Costa Rica.
[edit] External links
- Faculty page at University of Pennsylvania
- Third World Conservation: It's ALL Gardening recorded April 2004 at the Long Now Foundation
- Restoration ecologist interview with Omni April 1993
