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Titolo:
Optimal harvest of age-structured populations of moose Alces alces in a fluctuating environment
Autore:
Saether, BE; Engen, S; Solberg, EJ;
Indirizzi:
Norwegian Inst Nat Res, N-7485 Trondheim, Norway Norwegian Inst Nat Res Trondheim Norway N-7485 N-7485 Trondheim, Norway Norwegian Univ Sci & Technol, Dept Math Sci, N-7491 Trondheim, Norway Norwegian Univ Sci & Technol Trondheim Norway N-7491 1 Trondheim, Norway Norwegian Inst Nat Res, N-7485 Trondheim, Norway Norwegian Inst Nat Res Trondheim Norway N-7485 N-7485 Trondheim, Norway
Titolo Testata:
WILDLIFE BIOLOGY
fascicolo: 3, volume: 7, anno: 2001,
pagine: 171 - 179
SICI:
0909-6396(200109)7:3<171:OHOAPO>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
LIFE-HISTORY; BODY-MASS; LARGE HERBIVORES; NORWEGIAN MOOSE; CARCASS WEIGHT; DYNAMICS; CONSERVATION; NORWAY; SIZE; STRATEGIES;
Keywords:
age-specific harvesting; density dependence; environmental stochasticity; moose; stochastic population dynamics;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Saether, BE Norwegian Inst Nat Res, Tungasletta 2, N-7485 Trondheim, Norway Norwegian Inst Nat Res Tungasletta 2 Trondheim Norway N-7485
Citazione:
B.E. Saether et al., "Optimal harvest of age-structured populations of moose Alces alces in a fluctuating environment", WILDL BIOL, 7(3), 2001, pp. 171-179

Abstract

We analysed sex- and age-specific harvesting strategies of moose using an age-structured population model that includes density dependence as well asenvironmental stochasticity. In order to find the strategy that maximises the mean annual yield we simulated the process over a large number of years. The mean annual yield is a function of the three parameters (number of harvested individuals of calves, adult (greater than or equal to1 1/2 years old) bulls and adult females) that are involved in the definitions of the strategies. We compare, by numerical maximisation of a function in several variables, two harvest strategies: proportional harvesting, i.e. removal of acertain proportion of individuals in a given age and sex-class, and threshold harvesting, i.e. all individuals of a given sex- and age-class are harvested when the size of this subpopulation exceeds a certain threshold. In general, proportional harvest gives a smaller mean annual yield than threshold harvesting. The variance in the annual yield is, however, larger for threshold than for proportional harvesting. These differences between the two harvest strategies increase when the annual survival of calves is low, whenthere is high environmental stochasticity and when there is strong densityregulation operating on survival. For both harvest strategies, the optimalharvest strategy involves high harvest of calves and adult buns, whereas adult females should hardly be harvested.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 15:28:43