Effects of anthropogenic disturbances on the butterfly assemblage in an urban green area: the changes from 1990 to 2005 in Kanazawa Castle Park, Japan

Abstract

Kanazawa Castle Park (KCP) is an isolated urban green area in Kanazawa, Japan. A mature forest had developed there since 1949, but it was partially deforested from 1996 to 1999. Moreover, most of the grasslands in KCP were removed from 2000 to 2002. In this study, we report the damage to the butterfly assemblage by these anthropogenic disturbances and subsequent recovery after the disturbances, using previous literature on the butterfly assemblage in KCP from 1990 to 1994 and our monitoring data from 1999 to 2005. In addition, to understand urbanization effects, we also compared the butterfly assemblage of KCP with that of Tawara, a satoyama area 6 km away from KCP. Before the urbanization around KCP, KCP might have had a butterfly assemblage similar to Tawara. The previous articles indicate that 33 species lived in KCP before the partial deforestation. The number of generalist species (multivoltine and polyphagous species) was similar in KCP and Tawara (22 vs. 19), but that of specialist species (uni‐bivoltine and oligophagous species) was lower in KCP than in Tawara (5 vs. 15). Six species, composed of a bamboo grass feeder, mantle feeders, herb/grass feeders, and a multi‐feeder, disappeared from KCP after the deforestation and have not yet recolonized. The grassland removal also affected herb/grass feeders negatively, but they have been recovering quickly following the partial grassland recovery. Some species that disappeared after the deforestation were sporadically found from 2000 to 2005 probably due to immigration from the surrounding rural areas (the nearest one is 2 km away). For recolonization of the lost species, recovery of the interior and edge of the forest, which are the habitats for these species, is necessary.

Conservation where people work: A role for business districts and industrial areas in enhancing endangered butterfly populations?

“…Indeed, Öckinger, Dannestam, and Smith (2009) showed that early successional biotopes can accommodate high butterfly species richness in an urban environment. Ohwaki, Tanabe, and Nakamura (2008) also found that early successional grassland species recovered faster from anthropogenic disturbance in an urbanized area than late successional forest species. Altogether, our study shows that urban environments (in this case: existing business sites) may provide habitat for different butterfly species, including habitat specialists (of early-successional vegetation).…”

Diversity and density of butterfly communities in urban green areas: an analytical approach using GIS

“…P. xuthus was observed in all urban parks of various sizes (2.0-126 ha) in and around Osaka City, Japan (Imai 1998). P. xuthus did not decrease during the grassland removal and deforestation period in Kanazawa Castle Park, Japan (Ohwaki et al 2008). It is thought that P. xuthus may tolerate disturbances by humans because this species has a high dispersal ability and a broad range of food resources.…”

Drivers of species richness and abundance of butterflies in coffee–banana agroforests in Uganda

“…Apart from land use and farm management methods or farming practices (Weibull and Östman 2003), vegetation structure, quality of the matrix surrounding an agricultural habitat (Binzenhöfer et al 2008;Summerville et al 2008), diversity and types of habitats (Dessuy and de Morris 2007;Ngai et al 2008;Kumar et al 2009), landscape heterogeneity and habitat connectivity (Davis et al 2007) are important factors determining occurrence, movements, population dynamics, seasonality, persistence and longterm survival of Lepidoptera faunal communities in the agricultural landscapes (Dennis 2003;Greza et al 2004;Chay-Hernández et al 2006;Kivinen et al 2008;Öckinger and Smith 2008;Pickens and Root 2008;Stasek et al 2008;Dover and Settele 2009;Brückmann et al 2010). Generally, agricultural matrices that are more resembling a nearby forest patch maintain higher butterfly diversity than matrices with lesser shade cover (Summerville et al 2001;Kitahara and Watanabe 2003;Weibull and Östman 2003;Boriani et al 2005;Aviron et al 2007;Ohwaki et al 2007Ohwaki et al , 2008Barlow et al 2008;Bergman et al 2008;van Halder et al 2008;Marín et al 2009). …”