Eucalyptus in the British Isles

Eucalypts have been planted successfully in Great Britain and Ireland since the mid nineteenth century. While most of the seven hundred species of eucalypts are not suited to the relative cold of the climate of the British Isles, trials in Britain and Ireland have shown that certain species and subspecies can grow successfully. Further, some eucalypts are the fastest growing trees in the British Isles with mean annual increments of between 25 m3/ha/year and 38 m3/ha/year being reported. Rapid development of a wood biomass energy sector has encouraged a reassessment of the potential of eucalypts grown on short rotations as a source of energy. This article describes the history of eucalypts in the British Isles and their potential

Growth and survival of provenances of snow gums (Eucalyptus pauciflora) and other hardy eucalypts at three trials in England

Three trials of snow gums {Eucalyptus pauciflora) and other cold-tolerant eucalypts, planted in 1985, were assessed for height, diameter at breast height and survival. The trial sites were in southern England but differed in their climate, particularly maritime influence, summer moisture deficit, and in their altitude and soils. Patchy survival and windthrow within the trials posed constraints on the identification of trees of different locations (origins) that performed better. There were, however, some origins that showed good growth and survival across two or three trials. E. pauciflora ssp debeuzevillei from Mount Gininl (Australia) showed superior growth and survival at Thetford (East Anglia) and Torridge (Devon), while E. pauciflora ssp niphophila from Mount Bogong (also Australia) exhibited high survival across all three trials. If biomass production is the objective, many of the origins are too slow growing and faster growing species are available, including other eucalypts. The Mount Ginini origin of E. pauciflora ssp debeuzevillei was estimated to produce 7 m³ ha¯¹ y¯¹ at Thetford and 10 m³ ha¯¹ y¯¹ at Torridge at 26 years old, while Sitka spruce is estimated to yield 13m³ ha¯¹ y¯¹ on a similar rotation. A eucalypt species other than snow gum that showed some promise was f.perriniana, origin 'Smiggin Hole' (New South Wales, Australia) which yielded a mean annual increment of 25m³ ha¯¹ y¯¹ over 24 years at Chiddingfold (Sussex). However, survival was poor at Thetford and so it may be suited to only the warmest of sites (above accumulated temperature (AT5) of 1900)

Equivalence of foliar water uptake and stomatal conductance?

Foliar water uptake, FWU, the uptake of atmospheric water directly into leaves, has been reported to occur in nearly 200 species spanning a wide range of ecosystems distributed globally. In order to represent FWU in land‐surface models, a conductance term is required to scale the process to the canopy level. Here we show that conductance to FWU is theoretically equivalent to stomatal conductance and that under commonly occurring conditions vapour could diffuse into leaves at rates equivalent to those reported as FWU. We therefore conclude that such 'reverse transpiration' could partially, or even wholly, account for FWU in some plants.Australian Research Council, Grant/Award Number: FT11010045

New record on Rushia parreyssi (Mulsant, 1856), Melandrydae Leach, 1815 and other interesting beetles of the Sierra de Prades, Tarragona (Coleoptera)

En el estudio de la mortalidad de Pinus sylvestris por estrés hídrico en el área mediterránea, se ha querido ver la relación existente entre dicha mortalidad y los artrópodos, en concreto con los coleópteros. El área ibérica escogida para realizar el estudio ha sido el Tillar, situado en la sierra de Prades, en el término de Vimbodí i Poblet (Tarragona). La zona es un bosque mixto de P. sylvestris y Quercus sp. (robles y encinas) con árboles viejos y sin manejos recientes. Para conocer la fauna de coleópteros relacionados con P. sylvestris, se ha realizado una prospección exhaustiva con trampas de interceptación de vuelo, de caída y de berlese in situ. Se ha recolectado un grupo de especies de gran interés faunístico que merecen ser comentadas independientemente del proyecto.In a study on drought-induced Pinus sylvestris mortality in the Mediterranean, we explored the relationship between trees’ mortality and arthropods, specifically with beetles. The Iberian area chosen for the study was the Tillar, located in the Sierra de Prades, nearby Vimbodí i Poblet (Tarragona). The area is in a mixed forest of P. sylvestris and Quercus sp. (oaks), including old trees and without any recent management. In order to study the fauna of beetles associated with P. sylvestris, we carried out a comprehensive survey by using flight interception traps, pitfall trap and in situ Berlese traps. We recovered a very interesting group of species which deserve to be discussed independently of the project

Net primary productivity of forest trees: A review of current issue

Forest growth is important both economically and ecologically and it follows a predictable general trend with age. Generally, the growth of all forests accelerates as canopies develop in young forests and declines substantially soon after the maximum leaf area is attained. The causes of this decline trend are multiple. Initially, age- and size-related declines were attributed to photosynthesis-respiration imbalance. Subsequently, several competing hypotheses have been proposed over the years, although nutrient and hydraulic limitation hypotheses appear to be the most likely to have caused it. In this paper, the authors attempt to review these hypotheses and concentrate on one related aspect, as this can set the scene for further examining the issues of age-related versus size-related processes

Age- and size-related changes in physiological characteristics and chemical composition of Acer pseudoplatanus and Fraxinus excelsior trees

Forest growth is an important factor both economically and ecologically, and it follows a predictable trend with age. Generally, growth accelerates as canopies develop in young forests and declines substantially soon after maximum leaf area is attained. The causes of this decline are multiple and may be linked to age- or size-related processes, or both. Our objective was to determine the relative effects of tree age and tree size on the physiological attributes of two broadleaf species. As age and size are normally coupled during growth, an approach based on grafting techniques to separate the effects of size from those of age was adopted. Genetically identical grafted seedlings were produced from scions taken from trees of four age classes, ranging from 4 to 162 years. We found that leaf-level net photosynthetic rate per unit of leaf mass and some other leaf structural and biochemical characteristics had decreased substantially with increasing size of the donor trees in the field, whereas other gas exchange parameters expressed on a leaf area basis did not. In contrast, these parameters remained almost constant in grafted seedlings, i.e., scions taken from donor trees with different meristematic ages show no age-related trend after they were grafted onto young rootstocks. In general, the results suggested that size-related limitations triggered the declines in photosynthate production and tree growth, whereas less evidence was found to support a role of meristematic age

Preliminary growth functions for Eucalyptus gunnii in the UK

This study represents the first attempt to develop growth functions for Eucalyptus gunnii grown in the UK. Functions relating height and age, height and DBH, cumulative volume and age and mean annual increment and age were developed using historic data. These indicated that stands in the UK achieved an average growth rate of 16 m3 ha−1 y−1 or approximately 8 Mg ha−1 y−1 of dry stem biomass at an age of twenty years. There is evidence that yields can be considerably higher where intensive silviculture, such as use of plastic mulches and nutrient inputs has been practised, such as at Daneshill in Nottinghamshire, where trees attained a height of 10.6 m in five and a half years. However, potential yields are often compromised by high mortality and a priority should be to identify areas in the UK where E. gunnii can be grown with low risk and also to choose well adapted genetic material