Details

Autor(en) / Beteiligte

• Karr, J R
• Dionne, M
• Schlosser, I J
• Ohgushi, T
• Price, PW (eds)
• Hunter, MD

Titel

Bottom-up versus top-down regulation of vertebrate populations: Lessons from birds and fish

Erscheinungsjahr

1992

Link zum Volltext

Beschreibungen/Notizen

• Trophic control in forest, lake, and stream vertebrates is a shifting mosaic of abiotic and biotic forces acting on seasonal and year-to-year time scales and at a diversity of spatial scales. Control mechanisms at any instant result from the accumulation of past events and current influences. These represent pressures impinging on the organism from within, from other organisms at the same and higher and lower trophic levels, and from the physical environment. Climatic or other irregularities (e.g., anthropogenic disturbances) tend to shift the balance among controlling processes. In short, proximate mechanisms regulating abundances of species result from variation in absolute and relative strength of many forces acting in space and time. The challenge is in understanding and predicting the ecological effects of these processes.