Buffer Zones

J S Schou, University of Aarhus, Roskilde, Denmark

PSchaarup, Danish Forest and Nature Agency, Copenhagen, Denmark

© 2008 Elsevier B.V. All rights reserved.

Introduction Types of Buffer Zones and Their Function

Appointing the Zone Case Study - Ammonia Buffer Zones in Denmark

Regulation within the Zone Further Reading


Buffer zones may serve a wide range of purposes covering from environmental to socioeconomic and military issues, but here the focus is on the use of buffer zones for environmental protection purposes. Basically, an environ mental buffer zone serves the purpose of changing an environmental pressure and, thus, effect occurring in a recipient adjacent to the zone. Therefore, buffer zones are closely connected to environmental problems of a site specific nature.

Usually, the designation of a buffer zone in itself does not lead to changes in environmental pressures. Therefore, an important part of defining buffer zones is to establish the specific regulation of activities within the zone. Thus, the designation of buffer zones can be struc tured into tree initial steps:

1. define the policy target;

2. establish the criteria for appointing the zone; and

3. define regulation within the zone

To support the policy choices an ex ante evaluation of different options should be performed, and the imple mentation should be followed by an ex post evaluation to evaluate the fulfillment of the policy target. Establishment of buffer zones in this article is seen as a policy strategy applied to realize a pre specified environmental objec tive; thus, focus here is on issues 2 and 3.

Appointing the Zone

The criteria for appointing the zone are of cause closely connected to the policy target. Knowing the policy target, the first step is to establish which areas that should be targeted to the buffer zones. This may lead to two types of buffer zones: zones changing the pressures on a location inside or adjacent to the zone, or zones changing pressures within the zone. In the former situation it is generally also useful to define the area outside the zone to which the pressures should be changed. An example of the first type of buffer zone may be a riparian buffer zone alongside a stream serving to reduce the erosion and loss of nutrients to the stream (see Figure 1). An example of the former type of zone could be a buffer zone along the coastline where domestic settlements are prohibited in order to secure the landscape.

As apparent from the two examples the specific loca tion of the zone is of importance. The simplest way to designate the zone is to appoint an area within a certain distance of the targeted location. However, natural con ditions such as soil types, slopes, and the dominant wind direction (in case of airborne pollution) may be relevant to take into consideration when appointing the zones. This implies that more complex criteria for appointing the zone may be efficient. One example could be to design a buffer zone dependent on the wind direction frequency if the aim is to reduce ammonia depositions to specific nature locations. Another example could be varying the width of riparian buffer zones depending upon the erosion potential of the adjacent fields.

Regulation within the Zone

The regulation applied within the buffer zone can either be mandatory, flexible, or voluntary. In the case of a mandatory regulation, this will typically consist of prohi bition or restrictions on the activities within the zone. This implies that land owners within the zone are subject to limitations in the property rights or - more far reaching -are obliged to carry out certain nature preservation. One example is the National Danish Nature Protection Act that requires land use to be unchanged within designated locations characterized by specific nature types.

The term 'flexible regulation' refers to policy measures regulating environmental pressures through the marked by application of taxes of tradable quotas. This regulation is difficult to target locally, and is thus, not likely to be a general feasible option within buffer zones.

In the case of voluntary regulation, the landowners are given the opportunity to engage in environment friendly

Figure 1 Example of the mandatory 2 m noncropped buffer zone along streams and rivers in Denmark. Photo by J. S. Schou.

schemes within the designated buffer zones. The scheme may either provide the landowners with the opportunity to enter subsidy payments targeted at reducing environ mental pressures within the buffer zone, for example, reduced pesticide use, or simply provision of advisory services targeted to landowners within the zone.

Mandatory, flexible, and voluntary regulation can of course also be applied in various combinations. One example could be ammonia buffer zones where farmers are faced with a mandatory requirement of reducing ammonia emissions to a prespecified level, but at the same time are eligible to apply for subsidies to imple menting ammonia abatement technologies.

Types of Buffer Zones and Their Function

Table 1 lists the most common types of environmental buffer zones described by their design and functions found in the international literature.

Case Study - Ammonia Buffer Zones in Denmark

On 1 January 2007 a new integrated environmental accreditation scheme for all livestock farms was passed in Denmark. According to this scheme all farms with more than 75 animal units (one animal unit correspond to the nitrate production of one jersey cow) have to be approved based on their extra loss of nutrients when applying for an increase of the number of animal units. The integrated approach means that all environmental emissions have to be considered in the application including ammonia emissions from the stables and man ure containers.

The general accreditation rule is that all the ammonia emissions from the new stables have to be generally reduced with more than 15% compared to the best avail able stable system. This general rule is supplemented by an individual regulation regarding the contribution of ammonia emission from the farms (if these are adjacent, i.e., situated within a buffer zone around) to the following types of nitrogen vulnerable areas: (1) raised bogs; (2) lobelia lakes; (3) moors larger than 10 ha and all moors in NATURA 2000 areas; (4) uncultivated, dry meadows larger than 2.5 ha and all uncultivated, dry meadows in NATURA 2000 areas; and (5) nitrogen vul nerable lakes in NATURA 2000 areas. Around these areas the regulation is divided into three parts:

1. Buffer zone I. If just one of new or modified stable or manure container of the farm is situated less than 300 m from the vulnerable area no increased emission is approved.

2. Buffer zone II. If just one of new or modified stable or manure container of the farm is situated less than 100 m from the nitrogen vulnerable area, a standardized emis sion calculation has to be carried out. The total contribution of ammonia deposition from the new or modified stables in the vulnerable area may not exceed 0.7 kgN m .In order to take the cumulating aspects into account the maximum accepted increase in the ammonia deposition descends if another farm with more than 75 animal units is situated close to the nitrogen vulnerable area; if only one farm is situated closer than 1000 m from the new or modified stables then the contribution of ammonia from the new or modified stables in the vulner able area may not exceed 0.5 kg N m 2. If two or more farms with more than 75 animal units are situated closer than 1000 m from the new or modified stables, the thresh old is 0.3 kgNm 2

3. Outside the buffer zones. No individual regulation of the ammonia emissions from the farms under environ mental approval.

The nitrogen vulnerable areas were pointed out by a national committee (Wilhjelm udvalget). Afterwards the areas were adopted as part of the third Aquatic Action Plan, and the regulation related to the ammonia buffer zones was implemented as part of the new law on envir onmental approval of livestock farms as the primary basis for the individual regulation of ammonia emissions.

The scope for making this graduate regulation with two buffer zones is to make a differentiated incitement for the farms to locate new or extended stables at a proper distance from the vulnerable areas. Further, buffer zones are considered as a cost effective way to focus the regula tion in areas where the environmental effect is significant. Furthermore, one of the scopes is to ease the adminis trative costs because only in buffer zone II the more complicated and costly calculations of emissions are

Zones with restrictions on land use or cropping technology on fields alongside rivers, streams, and lakes. Restrictions may imply a mandatory requirement of permanent grassland or no tilt from harvest until, e.g., April 1st. Primary function is to reduce erosion and nutrient losses. Secondary functions are to serve as habitats and establish connectivity between habitats.

Zones with restrictions on land use and mandatory rules of the future management. Primary function is to prevent new pressures within the zone and secure scenic views through the zone, e.g., by keeping the area free of domestic settlements or forest.

Zones adjacent to or within appointed habitats with restrictions on land use or other human activities. Primary function is to reduce external pressures on the wildlife and secondary function is to improve the habitat and establish connectivity between habitats.

Alternatively wildlife buffer zones can appoint areas where regulation of specific wildlife species is approved. An example could be a zone where predators such as wolfs feeding on domestic husbandry may be trapped or shot. Primary function is to secure domestic husbandry inside the zone and protect the predators outside the zone.

Buffer zones where ammonia emissions are specifically regulated around specific habitats. The regulation designated to the buffer zones can either apply to future changes in husbandry production, e.g., establishment of new stables in the zone, or to existing and future husbandry production. The primary function is to reduce the local contribution to eutrophication of the appointed habitats. A secondary effect is likely to be reallocation of livestock production to outside the zone.

Zones where in use of pesticides in general or specific active substances are prohibited. The zones are typically located along field margins adjacent to hedgerows, streams, and similar landscape elements. Primary function is to increase the conditions for wildlife by increasing the production of forage such as weeds and insects. Further, the pesticide free buffer zones will reduce the external pressures on the adjacent habitats due to reduced wind drift.

Table 1 Types of environmental buffer zones and their function Type Design and function

Riparian buffer zones

Landscape buffer zones

Wildlife buffer zones

Ammonia buffer zones

Pesticide free buffer zones needed. Furthermore, in order to reduce the administra tive burdens and to ensure the quality of the applications all environmental calculations (including ammonia emis sion calculations) and other information needed for the application for an integrated environmental approval are integrated in a new internet based digital application system (www.husdyrgodkendelse.dk).

See also: Environmental Impact Assessment and Application - Part 1; Landscape Planning.

Further Reading

Clarke AE, Wolf TM, Kuchnicki TC, Francois DL, Glaser JD, and Hodge VA (2004) Use of buffer zones for the protection of environmental habitats in Canada. Aspects of Applied Biology 71(1): 133 139.

Ducros CMJ and Joyce CB (2003) Field based evaluation tool for riparian buffer zones in agricultural catchments. Environmental Management 32(2): 252 267.

Ebregt A and De Greve P (2000) Theme Studies Series 5: Buffer Zones and Their Management. Wargeningen: National Reference Centre for Nature Management.

Hickey MBC and Doran B (2004) A review of the efficiency of buffer strips for the maintenance and enhancement of riparian ecosystems. Water Quality Research Journal of Canada 39(3): 311 317.

Martino D (2001) Buffer Zones Around Protected Areas: A Brief Literature Review. Ottawa: Carleton University.

Roe JH and Georges A (2007) Heterogeneous wetland complexes, buffer zones, and travel corridors: Landscape management for freshwater reptiles. Biological Conservation 135(1): 67 76.

Schou JS, Tybirk K, Hertel O, and L0fstr0m P (2006) Economic and environmental analysis of buffer zones to reduce ammonia loads to nature areas. Land Use Policy 23: 533 541.

Viaud V, Merot P, and Baudry J (2004) Hydrochemical buffer assessment in agricultural landscapes: From local to catchment scale. Environmental Management 34(4): 559 573.

Relevant Website

http://www.husdyrgodkendelse.dk Forside.

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