Bird communities in small native remnants of contrasting understorey condition within bluegum plantations

Abstract

The area of agricultural land converted to commercial plantations across Australia has expanded rapidly and includes large areas (0.5 M ha) planted to Tasmanian Blue Gum (Eucalyptus globulus) (National Forest Inventory 2005). The outcome of this for biodiversity conservation is still being evaluated. In general, plantations support more native faunal species than farmland, but less than native vegetation remnants (Lindenmayer & Hobbs 2004). However, the value of small remnants (<5 ha) to native fauna in plantations is unclear. For birds in plantations, small remnants may be important ‘stepping stones’ or provide small, high quality habitat patches within a larger habitat mosaic (Fischer & Lindenmayer 2002), especially for species that can exploit resources within plantations (Loyn et al. 2007). However, degradation by weed invasion can reduce the value of small remnants for bird conservation (Loyn 1987). A better understanding of the biodiversity value of small remnants is needed given that many plantation companies operating under forest product certification are now formulating approaches to managing biodiversity within their estates. Therefore, we examined bird communities in Tasmanian Blue Gum plantations (hereafter called bluegum plantations’), contrasting plantation areas with small remnants with predominantly exotic, and native, understoreys. Implications for remnant management and monitoring are discussed.