TY - JOUR

T1 - HeathMod

T2 - a model of the impact of seasonal grazing by sheep on upland heaths dominated by Calluna vulgaris (heather)

AU - Read, Jonathan M.

AU - Birch, Colin P. D.

AU - Milne, John A.

PY - 2002/6

Y1 - 2002/6

N2 - The dwarf shrub heather Calluna vulgaris is an important component of the UK landscape, with value for amenity, nature conservation and animal production. A model, called "HeathMod", is described, which investigates the impact of grazing on upland heather. It combines an empirical model of production with a simple process-based model of grazing impacts. Validation from short-term studies in the literature indicated that the model predicts grazing impacts well, although more studies of grazing impacts are required to confirm the model's accuracy. Analysis of the model allowed derivation of a simple general formula for predicting sustainable levels of grazing, given knowledge of local site productivity. Predicted levels of sustainable grazing were lower than previous estimates, mainly because the model predicts the long-term impacts of sustained grazing. Application of the model is most appropriate in areas where heather is in mixed-age stands, because there is inadequate information available to model interactions between grazing and degeneration in even-aged stands of heather. (C) 2002 Elsevier Science Ltd. All rights reserved.

AB - The dwarf shrub heather Calluna vulgaris is an important component of the UK landscape, with value for amenity, nature conservation and animal production. A model, called "HeathMod", is described, which investigates the impact of grazing on upland heather. It combines an empirical model of production with a simple process-based model of grazing impacts. Validation from short-term studies in the literature indicated that the model predicts grazing impacts well, although more studies of grazing impacts are required to confirm the model's accuracy. Analysis of the model allowed derivation of a simple general formula for predicting sustainable levels of grazing, given knowledge of local site productivity. Predicted levels of sustainable grazing were lower than previous estimates, mainly because the model predicts the long-term impacts of sustained grazing. Application of the model is most appropriate in areas where heather is in mixed-age stands, because there is inadequate information available to model interactions between grazing and degeneration in even-aged stands of heather. (C) 2002 Elsevier Science Ltd. All rights reserved.

KW - Calluna vulgaris

KW - grazing

KW - sugar pool

KW - sustainable management

KW - utilization

KW - SPHAGNUM COMMUNITY

KW - VEGETATION CHANGE

KW - GREAT-BRITAIN

KW - GROWTH

KW - PRODUCTIVITY

KW - DYNAMICS

KW - PLANT

KW - PHOTOSYNTHESIS

KW - CONSERVATION

KW - REGENERATION

U2 - 10.1016/S0006-3207(01)00187-2

DO - 10.1016/S0006-3207(01)00187-2

M3 - Journal article

VL - 105

SP - 279

EP - 292

JO - Biological Conservation

JF - Biological Conservation

SN - 0006-3207

IS - 3

ER -