Habitat Management: A Tool to Modify Ecosystem Impacts of Nitrogen Deposition?

Abstract

Atmospheric nitrogen deposition has been shown to affect both the structure and the function of heathland ecosystems. Heathlands are semi-natural habitats and, as such, undergo regular management by mowing or burning. Different forms of management remove more or less nutrients from the system, so habitat management has the potential to mitigate some of the effects of atmospheric deposition. Data from a dynamic vegetation model and two field experiments are presented. The first involves nitrogen addition following different forms of habitat management. The second tests the use of habitat management to promote heathland recovery after a reduction in nitrogen deposition. Both modelling and experimental approaches suggest that plant and microbial response to nitrogen is affected by management. Shoot growth and rates of decomposition were lowest in plots managed using more intensive techniques, including mowing with litter removal and a high temperature burn. Field data also indicate that ecosystem recovery from prolonged elevated inputs of nitrogen may take many years, or even decades, even after the removal of plant and litter nitrogen stores which accompanies the more intensive forms of habitat management.

Can management compensate for atmospheric nutrient deposition in heathland ecosystems?

“…They are also in the range reported by studies conducted in the British Isles (Kirkham 2001;Power et al 2001) but are somewhat lower than deposition rates in many regions in the Netherlands (Bakema et al 1994;Erisman & de Vries 2000). However, N deposition in the study area exceeded critical load values for dry heathlands (10-20 kg 1.…”

“…These differences are mainly related to the impact of the temperature of the fire, which strongly affects the amount of burned organic matter in the above-ground biomass and the organic layer (Forgeard & Frenot 1996;Power et al 2001). In addition, nutrient loss increases with increasing organic matter available for combustion (Diemont 1996).…”

Effects of experimental nitrogen additions on plant diversity in tropical forests of contrasting disturbance regimes in southern China

“…Habitat management practices (e.g., from harvesting/mowing) decreasing ecosystem N stocks and mitigating the effects of N additions have also been found in grassland or heathland ecosystems (Willems, 2001;Power et al, 2001;Barker et al, 2004). Barker et al (2004) suggested that intensive mowing treatments in heathlands could result in a shift in balance between competing species by decreasing the response of the originally dominated species to N deposition.…”

Estimating costs of nature management in the European Union : Exploration modelling for PBL’s Nature Outlook

“…Typically, in heathland vegetation sod cutting and removal of the top soil layer is used as an effective measure to remove nitrogen (e.g., Britton and Fisher, 2007;Power et al, 2001;Terry et al, 2004). In aquatic environments, like water bodies, dredging is applied to remove large quantities of accumulated nitrogen.…”