Az ökológia, a természetvédelem és a vízgazdalkodás kapcsolata

TY - JOUR

T1 - Az ökológia, a természetvédelem és a vízgazdalkodás kapcsolata

AU - Istvánovics, V.

AU - Somlyódy, L.

PY - 2000

Y1 - 2000

N2 - The first part of the paper analyses the two most important differences of ecological and engineering approaches: (i) The ecological approach covers the whole of the biosphere in the spatial sense (Figure 1.), the evolution of the world (Figure 2.), without having special scales. The engineering approach focuses, at the most, on a time horizon of a few decades length, without knowing whether the response of the ecosystem points, on the long run, to sustainability or non-sustainability (Figure 3.). In many cases it is not clear what special operational features of the system could serve as a basis for predicting the change (ii) An inherent characteristic of ecological systems is that there might be "surprise-like" occurences, that cannot be predicted, not even theoretically. These specialities require the use of planning principles, which are much different from those of the traditional engineering approach: prevention gains a key role, planning is flexible and based on the feed-back of the ecosystem. The second half of the paper deals with the ecological role of water, investigating the main mechanisms of the interventions of water management. Main elements of the "no-balance" paradigm of ecological succession are reviewed as the initial step (Figure 4). On the basis of the role of water ecological systems can be grouped into three categories:- water as the medium of aquatic ecosystems; a factor of disturbance in wetland habitat a limiting factor in the arid and semiarid terrestrial habitats. Short examples are given to demonstrate that regarding the interventions of water management, aquatic ecosystems are sensitive mainly to water quality and physical conditions (flow velocity, residence time, scouring), while wetland habitats are sensitive to the hydrological regime (Figure 5.). Terrestrial communities are sensitive to the changes of soil moisture and shallow groundwater level, as defined by the changes of precipitation conditions. Most of the strategies of water management would not eliminate natural ecosystems, but change their character basically, sometimes over very large regions. The most important ecological losses and benefits of water management interventions are listed item-by-item. They always occur simultaneously, but in the past the losses were dominating. The dialogues of ecologists and engineers and joint interdisciplinary research are needed for turning the benefits the dominating ones. A special feature of ecological systems is the relatively closed material cycling, which severely contradicts the anthropogenically induced open material cycling. The basic ideas of the integrated catchment management and landscape ecology are discussed shortly and the need for the development of the indices of sustainability, characterising the closeness of material cycles at catchment scale, is emphasised. The third part of the paper gives a review of the currently valid legal regulations relevant to nature conservation. There are several difficulties in the interpretation and application of legal regulations. Many of these stem from the subjectivity of the values of nature conservation. A stepforward would be to change the present "state-fixing" approach of nature conservation to the unambiguous definition of acceptable/desirable ecological target conditions. The protection of lakes against eutrophication provides a good example of the joint working of engineers and ecologists. The same type of approach could be established in other fields of water management. The initial step would be the launching of joint interdisciplinary research.

AB - The first part of the paper analyses the two most important differences of ecological and engineering approaches: (i) The ecological approach covers the whole of the biosphere in the spatial sense (Figure 1.), the evolution of the world (Figure 2.), without having special scales. The engineering approach focuses, at the most, on a time horizon of a few decades length, without knowing whether the response of the ecosystem points, on the long run, to sustainability or non-sustainability (Figure 3.). In many cases it is not clear what special operational features of the system could serve as a basis for predicting the change (ii) An inherent characteristic of ecological systems is that there might be "surprise-like" occurences, that cannot be predicted, not even theoretically. These specialities require the use of planning principles, which are much different from those of the traditional engineering approach: prevention gains a key role, planning is flexible and based on the feed-back of the ecosystem. The second half of the paper deals with the ecological role of water, investigating the main mechanisms of the interventions of water management. Main elements of the "no-balance" paradigm of ecological succession are reviewed as the initial step (Figure 4). On the basis of the role of water ecological systems can be grouped into three categories:- water as the medium of aquatic ecosystems; a factor of disturbance in wetland habitat a limiting factor in the arid and semiarid terrestrial habitats. Short examples are given to demonstrate that regarding the interventions of water management, aquatic ecosystems are sensitive mainly to water quality and physical conditions (flow velocity, residence time, scouring), while wetland habitats are sensitive to the hydrological regime (Figure 5.). Terrestrial communities are sensitive to the changes of soil moisture and shallow groundwater level, as defined by the changes of precipitation conditions. Most of the strategies of water management would not eliminate natural ecosystems, but change their character basically, sometimes over very large regions. The most important ecological losses and benefits of water management interventions are listed item-by-item. They always occur simultaneously, but in the past the losses were dominating. The dialogues of ecologists and engineers and joint interdisciplinary research are needed for turning the benefits the dominating ones. A special feature of ecological systems is the relatively closed material cycling, which severely contradicts the anthropogenically induced open material cycling. The basic ideas of the integrated catchment management and landscape ecology are discussed shortly and the need for the development of the indices of sustainability, characterising the closeness of material cycles at catchment scale, is emphasised. The third part of the paper gives a review of the currently valid legal regulations relevant to nature conservation. There are several difficulties in the interpretation and application of legal regulations. Many of these stem from the subjectivity of the values of nature conservation. A stepforward would be to change the present "state-fixing" approach of nature conservation to the unambiguous definition of acceptable/desirable ecological target conditions. The protection of lakes against eutrophication provides a good example of the joint working of engineers and ecologists. The same type of approach could be established in other fields of water management. The initial step would be the launching of joint interdisciplinary research.

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M3 - Article

AN - SCOPUS:0034434503

SP - 525

EP - 552

JO - Vizugyi Kozlemenyek

JF - Vizugyi Kozlemenyek

SN - 0042-7616

IS - 3-4

ER -