Assessing the Success of Restoration Plantings in a Temperate New Zealand Forest

Abstract

The success of restoration plantings in restoring indigenous forest vascular plant and ground invertebrate biodiversity was assessed on previously grass‐covered sites in the eastern South Island, New Zealand. The composition and structure of grassland, three different aged restoration plantings (12, 30, and 35 years old), a naturally regenerating forest (100 years old), and a remnant of the original old‐growth forest of the area were measured. The restoration plantings are dominated by the native tree Olearia paniculata, which is not indigenous to the study area. Despite this, indigenous forest invertebrate and plant species are present in all three restoration sites and with increasing age the restoration sites become compositionally more similar to the naturally regenerating and mature forest sites. In particular the regenerating vegetation of the restoration sites is very similar floristically to the regenerating vegetation of the naturally regenerating and mature forest sites, despite marked differences in the current canopy vegetation reflecting the presence of the planted O. paniculata. The presence of regeneration in all three restoration sites indicates that the functional processes that initiate regeneration, such as dispersal, are present. The majority of regenerating tree species (71%) are bird dispersed and it is clear that birds play an important role in the recolonization of plant species at these sites despite the absence of edible fruit attractive to frugivorous birds on O. paniculata, a wind‐dispersed species. The strong correlations between plant and invertebrate community composition and study‐site age (r = 0.80, −0.24, −0.68 for plants, beetles, and spiders, respectively) suggest that the restoration site plant and invertebrate communities are undergoing change in the direction of the naturally regenerating and mature forest communities. Without restoration, colonization of grassland by forest plants is very slow in the study area and the restoration plantings studied here have been successful because they have considerably accelerated the return to forest at these sites.

Beetle community responses to grey willow (Salix cinerea) invasion within three New Zealand wetlands

“…Our results agree with those of other similar studies, which suggest that the composition of beetles present at a site is related to environmental factors such as vegetative physiognomy (vegetation age, diversity, height and density) (Watts & Gibbs 2002;Grimbacher & Catterall 2007), presence of dead wood on the ground (Reay & Norton 1999) and LD (Sanderson et al 1995). With increasing age, restored plant communities in a mined peat bog at Torehape (35 km east of Whangamarino) become more diverse and structurally complex, resulting in the beetle community composition converging rapidly on the target community structure of an undisturbed peat bog (Watts et al 2008).…”

Passive and Active Restoration Strategies to Activate Soil Biogeochemical Nutrient Cycles in a Degraded Tropical Dry Land

“…These are issues to consider in selecting a restoration model and the degree and speed expected of the degradation process. Thus, an active model should be considered when the rate of degradation of the area of interest is high, because the planted species can be established quickly and create better conditions for a more diverse biological community as pointed by [5]. When the state and rate of degradation are not severe, the most appropriate model might be the passive restoration, allowing the ecosystem a natural 6 ISRN Soil Science recover [29], which had advantages from ecological and economic perspectives.…”

“…Passive restoration strategies imply minimal human intervention and are based on natural succession process, and in this way the restorer has a passive role regarding the process. On the other hand, active restoration strategies include planting trees at high density and their respective management [5]; this strategy implies a more active role of the restorer. Although passive restoration strategies are simple, inexpensive, and based on natural regeneration processes, they are not always successful [6,7].…”

More than just trees: Assessing reforestation success in tropical developing countries

“…Reforestation projects typically progress through two main stages: an initial 'establishment' phase and a long-term 'building' phase (Kanowski and Catterall, 2007). Reforestation success can therefore be viewed as a continuum from the successful establishment of the initial planting through to maturation and realisation of the full environmental and socioeconomic benefits of the forest (Reay and Norton, 1999). This means that the measures of success will differ at different stages in a reforestation project.…”

“…This means that the measures of success will differ at different stages in a reforestation project. Undertaking assessments at an early stage of a reforestation project can only indicate likely future success (Reay and Norton, 1999). As the forest matures more information is required to make judgements about environmental and socioeconomic success (King and Keeland, 1999;Reay and Norton, 1999).…”