Yosihiro Natuhara

Landscape evaluation for ecosystem planning

Landscape evaluation is important in the conservation of biodiversity and sustainable development. The objective of this paper is to review and explore methods for evaluation of landscapes for ecosystem planning. Ecosystem planning is the process of land use decision-making that considers organisms and processes that characterize the ecosystem as a whole. Risk assessments, precautionary principles, adaptive management and scenario approaches are adopted to cope with the uncertainty of nature, which is an obstacle in ecosystem planning. Special attention is needed in the analysis of status and troubleshooting in the planning scheme, which is a selection of the appropriate approach and model to find problems in the present situation. There are two approaches to set targets in ecosystem planning, the species approach and the ecosystem approach. The species approach aims to protect particular species, and the ecosystem approach aims to protect total ecosystems including the species. In Europe, ecotope or biotope mapping has been developed in ecosystem planning. An ecotope is often identified by vegetation that represents a group of wildlife, but many species require combinations of different ecotopes. Landscapes have come to be recognized as a unit for ecosystem planning. Potential assessment is a method to estimate a potential of a local space or a landscape to realize an ecosystem or species’ habitat, and this method has been used in HEP and GAP analysis in the USA and Ecological Networks in Europe. Some examples of ecosystem planning of national and regional scales in Japan are introduced.

Changes in Vegetations of Abandoned Paddies with Different Environment and Vegetation by Mowing and Plowing

We examined effect of vegetation management on the species composition in wetlands in a valley of hilly site (altitude 130-200 m) in Shiga Prefecture. The study site had been paddy fields until 20 years before the investigation was done. Two 1 x 1 m2 quadrats were mowed and other tow quadrats were tilled at eight stands of different types of vegetation. Cover of each species was recorded in these four quadrats and two control quadrats. Water level, water quality and light condition were recorded at each stands. Canonical Correspondence Analysis suggested that water level strongly affected on the species composition in the study site. The reed, Phragmites australis vegetation was formed in the stands with highest water level and Carex dispalata was formed in the site with lowest water level. Tilling and mowing also affect the species composition. These disturbances generally increased annual grasses and reduced perennial and tree species in general. However the magnitude and direction of the change were depend on the existing vegetation type.

Comparison in Breeding Performance of Great Tit, Parus Major Inhabiting in Urban Parks with Different Proportion of Tree Cover

Great tits inhabit various habitats; from natural forests to urban parks and gardens. But they are few in the urban area of Osaka that has been covered few vegetation historically. We investigated about their breeding performance in two urban habitats, the Expo memorial park (proportion of tree cover is 73.3%) and the University campus (22.2%) between 2002-2004. Clutch size, brood size, weight of nestlings were similar in both sites. But, the population density and feeding frequencies were higher in the Expo park than the University campus. The number of nestlings leaving the nest changed year by year in each site. Feeding range was larger in the University campus than the Expo park, so it is thought that pairs in the University campus enlarge their feeding range to increase feeding frequencies. We suggested that it is still difficult for great tits to inhabit suitably in the city center of Osaka, and connectivity of tree cover is important as well as vertical structure of woods to keep their population sustainably.