Almo Farina

Landscape structure and breeding bird distribution in a sub-Mediterranean agro-ecosystem

Richness, abundance and distribution of birds were investigated in the Aulella watershed,a mountainous area of 300 km2, located in the extreme northwestern corner of Tuscany, Italy in spring and summer, 1995. The study area encompasses five vegetation types (from Mediterranean maqui to upland beech forest) and three main land use categories (woodlands, mixed cultivated + urban areas, montane prairies). The recent history of land abandonment in the study area has produced a rapid expansion of shrubland and woodland, reducing cultivated areas to small patches interspersed in a woodland matrix. Richness, abundance and distribution of birds recorded at 414 points, randomly selected along secondary roads, and located using a Global Positioning System (GPS), were compared with topography, vegetation type and land use in a Geographic Information Systems (GIS) with a grid cell resolution of 200 × 200 m.Bird richness (55 species in all) and abundance are correlated: (a) negatively with the increasing altitude and increasing distance from cultivated areas; (b) positively with the increasing distance from woodlands and mountain prairies. Slope orientation appears to have a negligible effect on bird assemblages.Bird richness and abundance are significantly correlated with vegetation type. Cultivated areas support the highest bird richness and abundance that increase with patch size of the cultivated areas. Local extinction and/or reduction in within-species abundance of birds are expected to continue if the process of land abandonment continues.

Distribution and dynamics of birds in a rural sub-Mediterranean landscape

Abstract The richness and abundance of birds in a sub-Mediterranean rural landscape (north Italy, Massa Carrara Province) were investigated across two spatial scales (10km× 10km and5km× 5km), two functional scales (land use mosaic and ecotope) and two temporal scales (annual and seasonal). Information on birds collected using the line transect method was compared with some landscape attributes (altitude, orientation, patch size, distance from cultivations). Distribution, abundance and seasonal turnover of birds were described efficiently by land use cover and ecotopes, but altitude, orientation, patch size and neighboring patch types were also important. Pure crop areas and crops mixed within woodlands and farming villages were the areas preferred by birds especially out of the breeding period, although woodlands supported more stable birds assemblages over the year. The multiscalar approach proposed was an efficient strategy to investigate these bird assemblages living in a patchy rural mosaic in which resources were made seasonally available by agricultural practices. The recent landscape change due to abandonment of agriculture in most of the sub-Mediterranean mountainous rural areas and the consequent woodland encroachment were expected to produce impoverishment of both diversity and abundance of resident and migratory birds.

Introduction to landscape ecology

Landscape ecology is one of the youngest branches of ecology. It evolved after World War II in the countries of central and eastern Europe and only recently expanded into a unique, dynamic and integrated global science. Its roots are deep in geography as well as in geobotany and land management.

Emerging processes in the landscape

This chapter focuses mainly on processes that operate in a landscape across a range of spatiotemporal scales and which in turn influence many landscape patterns.

Methods in landscape ecology

This chapter is particularly important because it is an attempt to quantify, using different approaches, the main attributes of a landscape. Routines and practical examples are provided to guide the reader through a number of ways to quantify many but not all the attributes of landscapes.

Scaling patterns and processes across landscapes

In cartography scale represents the level of reduction of the real dimensions of the earth, and may be absolute or relative. In ecology scale is a fundamental concept, as organisms interact with the environment using an inherent perception of their surroundings (Powell 1989, Steele 1989). Most ecological phenomena show a scale dependence of measurement and Horne and Schneider (1995) recently reviewed the role of spatial variance in ecology.

Emerging patterns in the landscape

Landscapes are complicated systems that show many different patterns according to the scale of resolution and the components towards which the investigation is directed.

Principles, theory, and models

When we observe a detail of an object, it appears simple and neat, but when observed as part of the world, it appears complex. As recently argued by Goldenfeld & Kadanoff (1999), “the world contains many examples of complex “ecologies” at all levels”. An object is complex when it has structures composed of different working parts. Each part can function in a different way according to the context. Many systems are both complex and chaotic (unpredictable), and the entire planet can be considered in such way.

Management and conservation of landscapes

The application of landscape paradigms in practice means the use of methodological approaches to manage, conserve and restore land mosaics (Hansson & Angelstam 1991, Naveh 1992).

Acting in landscape ecology: Concluding remarks

Different approaches are registered in landscape ecology studies and each of these approaches seems completely different and dissonant. One approach considers processes as actors affecting, and responding to landscape constraints. Another approach is to consider the landscape as a large area. At this scale of resolution the spatial patterns of patches are compared and studied. Finally, another approach is to consider organisms in heterogeneous systems and to study their behavioural response. This approach also includes the human being. In this case landscape is considered as a large area in which remnants of original vegetation persist in a human dominated landscape. This approach is very familiar to geographers, human ecologists, planners, and landscape architects. The analysis of a constructed landscape is carried out, i.e., the landscape is considered the vital space of humanity, countries, regions, cities, villages, countryside, farms. It is at this level that landscape ecology has to be applied to improve the quality of human life, and to protect the diversity of life, assuring a healthy system.