The dynamics of a Carabus auronitens population

Autori

• Robert Baumgartner

Parametri

• Biologia
• Scienze Naturali

Maggiori informazioni sul libro

Life history parameters of a Carabus auronitens population were studied in a 0.2 ha enclosure from 1982 to 2001. A significant 73.4% of the variation in net reproductive rate (Bi) is influenced by temperature (PTi) during a critical early development period in late spring, along with an “expectation value” (BEVi). PTi exhibits a 4-year periodicity, while BEVi represents the mean value of PTi over this cycle. The population adapts to PTi's periodicity by reducing reproductive efforts in early spring when low temperatures are anticipated, despite otherwise favorable conditions. This strategy appears to enhance survival rates. A model is proposed to explain how beetles gauge whether PTi will be optimal or suboptimal. A crucial “information factor” is beetle abundance; when PTi is likely to be unfavorable, beetle density tends to be higher in the current and preceding spring. The model illustrates the adaptive interplay between density-dependent effects and a risk-spreading strategy. Key concepts include population dynamics, abiotic factors, climate periodicity, density dependence, and survival strategies.

Lingua: Inglese

Pubblicato: 2005