TY - JOUR

T1 - Can prescribed burning compensate for atmospheric nutrient loads in wet heathlands?

AU - Haerdtle, Werner

AU - Niemeyer, Thomas

AU - Assmann, Thorsten

AU - Meyer, Hartmut

AU - von Oheimb, Goddert

N1 - Literaturverz. S. 171 - 174

PY - 2007/6/20

Y1 - 2007/6/20

N2 - The increased deposition of nutrients from the atmosphere has contributed to widespread changes in wet heathland ecosystems throughout Europe. As a result, management measures are nowadays considered a tool with which to mitigate impacts of atmospheric nutrient loads by reducing nutrient stores in the above-ground biomass and soils. A burning experiment was carried out in order to evaluate the effects of prescribed winter burning on the nutrient budgets of an extensive wet heathland complex in NW Germany (with particular reference to growth limiting N and P, but also Ca, K, and Mg). Changes in nutrient budgets were calculated by analysing the current input (atmospheric deposition), the output due to biomass combustion, and N losses due to denitrification. In the study area, atmospheric inputs amount to 3.31 g m -2 yr -1 for N, and <0.05 g m -2 yr -1 for P. Mean N stores in the above-ground biomass are 9.34 and 9.66 g m -2 (in Calluna-Erica- and Calluna-dominated wet heaths, respectively), and biomass P contents in both vegetation types amount to 0.43 g m -2. From these stores, 47-68 % (for N) and 2-16% (for P) were removed by burning (taking into consideration the return of nutrients as a result of ash deposition). Nitrogen losses owing to denitrification range between 0.5 and 1.6 g m -2 yr -1 and may, thus, compensate for about 15-48% of the atmospheric input. However, calculations of input/output-ratios show that prescribed burning is insufficient to counterbalance present-day atmospheric nutrient loads since management cycles usually exceed a 10-year interval. Our results suggest that wet heaths managed by means of prescribed burning will accumulate nutrients, particularly N, in the long term. As a means of preserving a balanced nutrient budget on a long-term basis, high-intensity measures (e.g. high intensity mow), applied in combination with low-intensity measures, will be an indispensable instrument in wet heathland preservation.

AB - The increased deposition of nutrients from the atmosphere has contributed to widespread changes in wet heathland ecosystems throughout Europe. As a result, management measures are nowadays considered a tool with which to mitigate impacts of atmospheric nutrient loads by reducing nutrient stores in the above-ground biomass and soils. A burning experiment was carried out in order to evaluate the effects of prescribed winter burning on the nutrient budgets of an extensive wet heathland complex in NW Germany (with particular reference to growth limiting N and P, but also Ca, K, and Mg). Changes in nutrient budgets were calculated by analysing the current input (atmospheric deposition), the output due to biomass combustion, and N losses due to denitrification. In the study area, atmospheric inputs amount to 3.31 g m -2 yr -1 for N, and <0.05 g m -2 yr -1 for P. Mean N stores in the above-ground biomass are 9.34 and 9.66 g m -2 (in Calluna-Erica- and Calluna-dominated wet heaths, respectively), and biomass P contents in both vegetation types amount to 0.43 g m -2. From these stores, 47-68 % (for N) and 2-16% (for P) were removed by burning (taking into consideration the return of nutrients as a result of ash deposition). Nitrogen losses owing to denitrification range between 0.5 and 1.6 g m -2 yr -1 and may, thus, compensate for about 15-48% of the atmospheric input. However, calculations of input/output-ratios show that prescribed burning is insufficient to counterbalance present-day atmospheric nutrient loads since management cycles usually exceed a 10-year interval. Our results suggest that wet heaths managed by means of prescribed burning will accumulate nutrients, particularly N, in the long term. As a means of preserving a balanced nutrient budget on a long-term basis, high-intensity measures (e.g. high intensity mow), applied in combination with low-intensity measures, will be an indispensable instrument in wet heathland preservation.

KW - Biology

KW - calluna vulgaris

KW - Molinia caerulea

KW - n/P-Ratio

KW - Nitrogen deposition

KW - nutrient gudgets

KW - nutrien limitation

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=34547117856&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/f14b2d41-d9f8-39ec-8389-1e263beb0d9e/

U2 - 10.1127/0340-269x/2007/0037-0161

DO - 10.1127/0340-269x/2007/0037-0161

M3 - Journal articles

VL - 37

SP - 161

EP - 174

JO - Phytocoenologia

JF - Phytocoenologia

SN - 0340-269X

IS - 2

ER -