RESPONSES OF EUCALYPTUS CAMALDULENSIS SPROUTS TO SHADE: AN EVALUATION OF CANOPY PLASTICITY

Abstract

SUMMARYEucalyptus spp. is the main tree used in cellulose production worldwide, cultivated mostly in extensive monocrop plantations. However, due to concerns on environmental impacts, fear on decrease of food production related to the size of cultivated area, its location near human settlements with few jobs generation, eucalypt cultivation is no longer encouraged in many places. At the same time, large plantations hold the opportunity to integrate eucalypt into agroforestry systems (AFS) in a variety of production systems with many social, economical and environmental advantages. In this study we studied canopy modifications of E. camaldulensis sprouts under different degrees of shade. The plants were located on a gradient of available solar irradiation ranging from 51 to 94%. E. camaldulensis showed canopy plasticity with modified radiation interception patterns under diverse irradiations. Most of these variations were of small amplitude with some important variables remaining almost unchanged (leaf density, canopy percentage, tree, trunk and canopy height) or increasing only slightly (leaf area index and canopy opening). The main changes presented by E. camaldulensis, with a steep increase towards full sun, were: foliage area, canopy surface, canopy volume and area of canopy projection. In order to design appropriate agroforestry systems with young eucalypt growing under the shade of other crops, it is necessary to determine at which point the observed variable changes can support reasonable production.

Blue, green and in-between: objectives and approaches for evaluating wetland flow regimes based on vegetation outcomes

“…Assessing processes such as the recruitment and maintenance of age cohorts requires evaluation at the appropriate scale and often consideration of multiple scales. Recruitment patterns can vary considerably over space and time, and identification of appropriate scales to monitor recruitment outcomes will be influenced by seed dispersal and establishment patterns of individual species; for example, tree recruitment may be constrained within established patches of woody wetland vegetation by shading from dense canopies (Righi et al 2016) or the potential allelochemical effects of leaf litter . As a result, recruitment is often patchily distributed within wetlands, occurring more frequently at the edge of the tree line or in unwooded patches, akin to tree fall gap dynamics in rainforests, albeit at a much larger scale.…”

Planting configuration affects productivity, tree form and survival of mallee eucalypt in farm forestry plantings

“…Work on other species in higher rainfall and lower insolation environments indicate that shading can limit tree growth (Long & Smith, 1984;Righi et al, 2016;Pommerening & Sánchez Meador, 2018). Wildy and Pate (2002) found that shaded E. kochii coppice produced less biomass than unshaded coppice in the first year post-harvest.…”

Comparisons of Four Methods for Thinning Eucalyptus Hybrid Coppice Shoots in Brazil

“…Eucalyptus species are the most commonly used in commercial plantations in Brazil and most of their species have lignotubers, a structure which gives them the ability to sprout when cut [4,5]. This capacity enables implementing the sprout conduction regime, known as coppice management [6,7]. According to Gadelha et al [8] and Gonçalves et al [9], conducting sprouts does not require seedling purchase and soil preparation costs, in addition to reducing the need and consequently the costs of fertilization.…”