, 2012). As previously noted, early successional structures also are in short supply and their scarcity threatens some species ( Litvaitis, 2001, Swanson et al., 2010 and Greenberg et al., 2011). A landscape of managed forest stands of similar structure
(and possibly age) can be transformed using variable retention harvesting ( Fig. 14). The amount of retained stems (or basal area) can be varied, as well as the spatial arrangement of retention stems, either aggregated or dispersed (e.g., Sullivan see more et al., 2001). Diversity and spatial arrangements of microhabitats can influence successful dispersal by animals into restored sites and considerable time may be needed for some components to develop ( Vesk et al., 2008). For example, Christie et al. (2013) found that placing small woody debris piles near intact Jarrah forest in southwestern Australia
facilitated colonization of restored mined sites by Napolean’s skink (Egernia napoleonis). Legacies from past land use or from previous stands may influence selleck chemicals llc the restoration trajectory (Foster et al., 1998, Foster et al., 2003 and Kettle et al., 2000). From the perspective of restoration objectives, such legacies may be beneficial or detrimental. As discussed earlier, deadwood in its various forms and conditions provides desirable function by providing habitat and other resources to a wide variety of species (Harmon et al., 1986). When it is missing in a managed stand, actions to restore it are needed. Conversely, when it is present in a managed stand, actions to maintain
Thalidomide it as an important legacy are needed, particularly after regeneration harvesting (Boddy, 2001 and Nordén et al., 2004). As Jonsson et al. (2005) pointed out, no single target volume of deadwood exists that meets the requirements of all species, so they recommended that a variety of deadwood be maintained because all types of deadwood probably have associated species. Desirable amounts of deadwood may be ascertained from old forest stands that have been conservatively managed or protected (e.g., Fridman and Walheim, 2000). Quality of deadwood is primarily determined by size and stage of decay (Jonsson et al., 2005); in managed forests, deadwood size is skewed toward smaller diameters (Fridman and Walheim, 2000, Jonsson et al., 2005 and Brumelis et al., 2011), therefore often the challenge in restoration is to create larger diameter deadwood. Undesirable legacies in forests are numerous (Foster et al., 2003) and often so ingrained in the landscape that their influence on forest development is taken for granted. These include eroded or infertile soil, depauperate species composition from exploitive harvesting (Allen et al., 2001) or high herbivore pressure (Nuttle et al., 2013), altered drainage (Yaalon and Yaron, 1966, Gardiner and Oliver, 2005 and Hughes et al.