Modelling the Effect of Microsite Influences on the Growth and Survival of Juvenile Eucalyptus globoidea (Blakely) and Eucalyptus bosistoana (F. Muell) in New Zealand

Abstract

The effect of microsite on juvenile forest plantation yield is rarely explored. This is because juvenile plantation growth is considered to be reasonably homogenous due to a lack of resource competition between trees prior to canopy closure. However, models of juvenile plantation height growth and survival that are sensitive to microsite variation could aid decisions relating to site preparation, plantation establishment and early silvicultural treatments. In this study, juvenile Eucalyptus bosistoana and E. globoidea height growth and survival proportion were modelled against topographic and environmental microsite characteristics as independent variables. The experiment included three different sites situated in a sub-humid region of New Zealand. A total of 540 plots were planted with 18,540 trees in regular rows and columns. Micro-topographical variables significantly influenced height growth and survival proportion of both E. bosistoana and E. globoidea, but species differed in their responses. More sheltered microsites yielded greater height growth and survival for both species. The height of both species was influenced by wind exposure, morphometric protection, and distance from the nearest ridge. E. bosistoana height was also influenced by topographic position and surface plan curvature. Survival was affected by surface profile curvature for both species, while E. globoidea survival was also impacted by surface plan curvature and distance from the top ridge. This study identified microsite factors influencing juvenile height and survival of two Eucalyptus species.

Competition Influences Tree Dimension, Biomass Distribution, and Leaf Area Index of Eucalyptus Urophylla in Dryland Ecosystems at East Nusa Tenggara

“…This circumstance can possibly occur given the gradient of biophysical characteristics in micro-site conditions. Our argument was also supported by the previous studies which reported a variety of soil fertilities in a compartment (Washitani and Tang, 1991, Gömöry et al, 2011, Salekin et al, 2019. Difference in soil fertility would provide the various resource supply for supporting tree growth.…”

Within-site drivers for soil nutrient variability in plantation forests: A case study from dry sub-humid New Zealand

“…Next, surfaces for topographic variables were derived from the DTM (Salekin et al, 2019). Each of these topographic variables are different ways of describing the structure and shape of the topographic relief.…”

“…In some countries, production forestry is moving towards a precision approach that is used in agriculture (Bhakta et al, 2019;Dyck, 2003). Precision forest management requires fine-scale data covering all aspects of forested ecosystems (Salekin et al, 2019). However, one of the main hindrances to precision forestry is acquiring fine-scale soil data, as soil surveys have traditionally overlooked variability within map units (Basayigit and Senol, 2008;Lin et al, 2005).…”

The influence of stocking levels, clone, fertilization, and weed control on surface CO2 efflux in a mid-rotation Pinus radiata D. Don plantation in Canterbury, New Zealand

“…1b), but may rise above 30 °C. Winters have daytime maximum temperatures from 7 to 14 °C (Salekin et al 2019;NIWA 2020) (Fig. 1b).…”