Small Cultural Forests: Landscape Role and Ecosystem Services in a Japanese Cultural Landscape

Abstract

Small woods, linear tree formations, or scattered trees in agricultural areas are receiving increasing attention for their multifunctional role, especially if associated to cultural landscapes. Osaki Kodo’s Traditional Water Management System for Sustainable Paddy Agriculture represents one of the most important cultural landscapes (satoyama) of Japan, also included by the FAO in the GIAHS (Globally Important Agricultural Heritage Systems) Programme. Here, local farmers surrounded their farmhouses with small woods, called igune, as a protection from the cold winter wind, creating a peculiar landscape characterized by an intensively cultivated plain dotted with small wood patches. The research aims at deepening the knowledge of igune, evaluating the landscape role and monitoring their changes in the last 20 years, through multitemporal and spatial analyses. In addition, a literature review has been performed to assess other Ecosystem Services (ESs) provided by igune within the study area. Despite the limited overall surface, 1737 igune and small woods currently characterize the area, with 72% of them having a surface smaller than 0.5 hectares. The multitemporal and spatial analyses show that their number, distribution, and spatial pattern remained almost completely unchanged in the last 20 years, testifying their key role in characterizing the local cultural landscape. Least-Cost Path analysis highlighted a crucial role in connecting the two forest nodes of the region, as 90% of the path passes inside more than 70 different igune and small woods. Literature review demonstrated that igune and other small woods still provide various ESs, including ecological network, habitat for various flora and fauna species, firewood, and byproducts, as well as cultural services. This maintenance of the traditional management in cultural forests is crucial not only to retain their landscape role, but mostly for the preservation of the related ESs, as changes in the management can lead to changes in horizontal and vertical structures, and in species composition.