Presentation on theme: "Carrying Capacity: Concept and Critique Sources: Caughley, G. and J. H. Lawton. 1981. Plant-herbivore systems. Ch. 7 in Theoretical Ecology (R. M. May,"— Presentation transcript:
Carrying Capacity: Concept and Critique Sources: Caughley, G. and J. H. Lawton. 1981. Plant-herbivore systems. Ch. 7 in Theoretical Ecology (R. M. May, Editor). Blackwell Sci. Publ. McCullough, D. R. 1992. Concepts of large herbivore population dynamics. Pages 967-984 in Wildlife 2001:Populations (Edited by D. R. McCullough and R. H. Berrett). Elsevier Applied Science. Miller, K. V. and J. M. Wentworth. 2000. Carrying capacity. Ch. 7 in Ecology and Management of Large Mammals in North America (S. Demaris and P. R. Krausman, Eds.), Prentice Hall. Ricklefs, R. and G. L. Miller. 2000. Ecology. W. H. Freeman and Co. Key Points: The concept of carrying capacity has many meanings/definitions Many important management decisions are based on concepts of carrying capacity A critical perspective on the concept, its verbal and mathematical definitions, and its applications are key to intelligent management and policy
Originally modified from McCullough 1992 What is Carrying Capacity?
Problems with Definitions KCC: does provide an understandable benchmark. Faulted on two issues: population may never reach KCC because of resources that are limiting other than food resources KCC has high temporal variance so average value mean may not be useful HOWEVER, that other limiting factors exist does not mean that environmental limits do not exist. …relevant to distinguish between limits of the support capacity of the land, the mortality imposed by human or natural predation…, or that combination….. that determines the numbers of a population (McCullough 1992) K-Carrying Capacity Does CC need to be constant? Isnt the VAR(CC) important to understand and thus provide guidance in using measures of CC in management? I-Carrying Capacity ????
Carrying Capacity as an Equilibrium Originally modified from Caughley 1979
Originally modified from McCullough 1979 Application of Carrying Capacity with Environmental Variation
Carrying Capacity as a Useful Concept In Ecology and Natural Resource Management??? Discussion led by Kaia and Todd: Papers include Dhondt 1988 and McCleod 1997