Functions of Windbreaks in the Landscape Ecological Network and Methods of Their Evaluation

Linear elements in the agricultural landscape, particularly windbreaks, reduce the wind speed and improve the microclimate in the protected zone. They offer many direct effects on agricultural production with maximum benefits of ecosystem biodiversity. Despite the indisputable advantages and favourable effects of permanent linear vegetation elements, their representation in the agricultural landscape is not as frequent as it used to be. Moreover, the formerly planted elements do not fulfil their original function due to the overgrowth and neglected maintenance. The optimum spatial and functional organisation of the newly proposed linear elements requires evaluation of the existing linear vegetation, its functional parameters and involvement in the landscape ecological network. Our report presents methods for the evaluation of the linear elements, both from the aspect of their internal structure and species composition (category A) and their involvement in the functional system (category B). The evaluation is based on seven established criteria and results in a point scoring system that reflects the characteristics of the reference criteria. In five selected localities, we tested the linear elements as individuals by the A method and their integrity by the B method of evaluation. In one locality only, the state of windbreaks was assessed as functional; at two localities, they were found as conditionally functional, and at two other localities, the state of the windbreaks was assessed as non-functional. An example of the evaluation of individual windbreaks (category A) is demonstrated in model localities in South Moravia, Czech Republic. The results of the evaluation of the model localities thus point out an unsatisfactory state of the linear elements in the region of South Moravia and the need to accord them increased care and to establish new plantations under professional supervision. Their building can be sped up by using the tools of land consolidation.