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)

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

Simulation of greenhouse gases following land-use change to bioenergy crops using the ECOSSE model : a comparison between site measurements and model predictions

This work contributes to the ELUM (Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial) project, which was commissioned and funded by the Energy Technologies Institute (ETI). We acknowledge the E-OBS data set from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu).Peer reviewedPublisher PD

Intimate mixtures of Scots pine and Sitka spruce do not increase resilience to spring drought

Understanding how we can increase the resilience of forest systems to future extreme drought events is increasingly important as these events become more frequent and intense. Diversifying production forests using intimate mixtures of trees with complementary functional traits is considered as one promising silvicultural approach that may increase drought resilience. However, the direction and magnitude of the drought response of mixed-species stands relative to monospecific stands of the same species can vary with species identity, relative abundance and levels of competition in a focal tree's immediate neighbourhood. Using a long-term experiment where tree-level mortality and the neighbourhood composition of each tree was known, we assessed the radial growth response of 24-year-old Scots pine (Pinus sylvestris) and Sitka spruce (Picea sitchensis) trees in intimately mixed and monospecific stands to a short-duration, high-intensity spring drought in Scotland. Mixing proportions included 25:75, 50:50 and 75:25 of P. sylvestris and P. sitchensis. At the species level, Scots pine was more drought resistant and resilient than Sitka spruce, while Sitka spruce showed higher recovery. Surprisingly, neither pre-drought tree size nor neighbourhood competition were significantly associated with resistance or resilience to drought, and trees of both species within monospecific stands showed higher recovery and resilience than trees growing in mixed stands. Our study suggests intimate mixtures of these two species may not be an effective way to mitigate the negative impacts of future extreme spring drought events. Given that these two species comprise almost 70% of coniferous forests in the UK, our results highlight the pressing need to better understand their vulnerability to drought and the conditions under which intimate mixtures of these species could be beneficial or detrimental. Such knowledge is essential if we are to enable forest managers to effectively plan how to adapt these forests to the challenges of a changing climate

Developing the WCRF International/University of Bristol methodology for identifying and carrying out systematic reviews of mechanisms of exposure-cancer associations

Abstract Background: Human, animal, and cell experimental studies; human biomarker studies; and genetic studies complement epidemiologic findings and can offer insights into biological plausibility and pathways between exposure and disease, but methods for synthesizing such studies are lacking. We, therefore, developed a methodology for identifying mechanisms and carrying out systematic reviews of mechanistic studies that underpin exposure–cancer associations. Methods: A multidisciplinary team with expertise in informatics, statistics, epidemiology, systematic reviews, cancer biology, and nutrition was assembled. Five 1-day workshops were held to brainstorm ideas; in the intervening periods we carried out searches and applied our methods to a case study to test our ideas. Results: We have developed a two-stage framework, the first stage of which is designed to identify mechanisms underpinning a specific exposure–disease relationship; the second stage is a targeted systematic review of studies on a specific mechanism. As part of the methodology, we also developed an online tool for text mining for mechanism prioritization (TeMMPo) and a new graph for displaying related but heterogeneous data from epidemiologic studies (the Albatross plot). Conclusions: We have developed novel tools for identifying mechanisms and carrying out systematic reviews of mechanistic studies of exposure–disease relationships. In doing so, we have outlined how we have overcome the challenges that we faced and provided researchers with practical guides for conducting mechanistic systematic reviews. Impact: The aforementioned methodology and tools will allow potential mechanisms to be identified and the strength of the evidence underlying a particular mechanism to be assessed. Cancer Epidemiol Biomarkers Prev; 26(11); 1667–75. ©2017 AACR.</jats:p

The potential for Eucalyptus as a wood fuel in the UK

Considerable potential exists in the UK for utilising woody biomass, grown under short rotation forestry management systems, to produce electricity or heat. There are benefits to using biomass in generating heat and power the main environmental benefit being from substituting for fossil fuel combustion and consequent carbon emissions. Woody biomass production in short rotation forestry involves growing single stemmed trees rather than coppice over rotations of between 10 and 15 years. Eucalypts are particularly suited to such biomass production as they exhibit relatively high wood density, have suitable chemical characteristics, exhibit low moisture content and can be easily harvested all year around using conventional machinery if single-stemmed growth form is maintained. The UK has a climate that is not well suited to the majority of eucalypts. However, there is a small number of eucalypt species that can withstand the stresses caused by frozen ground and desiccating winds or sub-zero temperatures that can occur. These species are from more southern latitudes and high altitude areas of Australia. However, even the most cold resistant species can be damaged by UK winter climate extremes and therefore careful matching of species to site environmental constraints is critical. Informed decision making is made problematic by the small area and limited distribution of current planting, although it is clear that particularly cold areas and for most species, sites with poor drainage should be generally avoided. This article provides a discussion of the potential of, and constraints to, using eucalypts for biomass in the UK and provides a tentative list of recommended species, their potential growth rates and their advantages and disadvantages. Highlights: Eucalyptus in plantations has potential in the UK as a source of woody biomass. Fast early growth enables high productivity over short rotations. Unseasonal frosts and unusually cold winters pose a risk. It is not clear whether climate change will benefit or hinder use of eucalypts for biomass in the UK

Frost damage to eucalypts in a short-rotation forestry trial in Cumbria (England)

Cold is the main climatic constraint to planting eucalypts in Britain and the winter of 2009-2010, the coldest in thirty years, proved particularly challenging for their survival. Damage to transplants planted in May 2009 of two species of eucalypts, Eucalyptus gunnii and Eucalyptus nitens, were assessed over the winter of 2009/2010 at a trial in Cumbria, northern England. Larger trees were found to have exhibited less cold damage by the end of January 2010, but by May there were no significant differences in survival due to tree size. By late January, there were statistically significant differences in damage between E. gunnii and E. nitens with the former being more cold tolerant. However, damage at the end of January, after minimum temperatures of -14 oC, did not appear serious, yet by May the survival of E. gunnii was 37% and for E. nitens was less than 1%. As larger trees exhibited relatively less frost damage it is recommended that intensive silviculture be practiced to ensure trees are between 1 and 1.5 m tall prior to their first winter to reduce the extent of damage through frost

Results of a species trial of cold tolerant eucalypts in south west England

A trial of six cold-tolerant eucalypt species, planted in 1981 near Exeter, in south west England, was assessed in 2010 for height, diameter at breast height and survival. The predicted soil moisture deficit on the site is low and it is relatively warm (AT 1662.5) and sheltered (DAMS 126), although it experienced a succession of cold winters in the 6 years following planting.The growth of some E. delegatensis was very rapid; the productivity of the seedlot having best survival (48%) was38 m3 ha-1 yr-1 although this seedlot was collected from one mother tree and was unrepresentative of the broader population at that location. Of the closely-related species E. johnstonii and E.subcrenulata, seedlots recorded as E. johnstonii had poor average survival (26%) and growth (7 m3 ha-1 y-1), while E. subcrenulata seedlots from Mount Cattley, Tasmania exhibited both good average survival (68%) and growth (25 m3 ha-1 y-1), with progenies from individual mother trees performing substantially better. Based on the results of this assessment, selected sources of E. subcrenulata appears suitable for woody biomass production in sheltered sites in south west England.Of the closely related E. coccifera and E. nitida, the former showed better survival, at 18% against 5%. The poor performance of these species is surprising, as the latter species, which is less cold-tolerant, has grown and survived well elsewhere in south west England, and overall survival of both species at Exeter in 1995 was 60%. The good cold-tolerance andgrowth of certain seedlots from single mother trees within provenances suggests that much of the variation in performance of all species is genetically determined at family rather than provenance level. The larger surviving trees in the trial could provide germplasm for further trials, with the possibility of later conversion of parts of the Exeter trial to seed stands

Implications of land-use change to short rotation forestry in Great Britain for soil and biomass carbon

Land-use change can have significant impacts on soil and aboveground carbon (C) stocks and there is a clear need to identify sustainable land uses which maximize C mitigation potential. Land-use transitions from agricultural to bioenergy crops are increasingly common in Europe with one option being Short Rotation Forestry (SRF). Research on the impact on C stocks of the establishment of SRF is limited, but given the potential for this bioenergy crop in temperate climates, there is an evident knowledge gap. Here, we examine changes in soil C stock following the establishment of SRF using combined short (30 cm depth) and deep (1 m depth) soil cores at 11 sites representing 29 transitions from agriculture to SRF. We compare the effects of tree species including 9 coniferous, 16 broadleaved and 4 Eucalyptus transitions. SRF aboveground and root biomass were also estimated in 15 of the transitions using tree mensuration data allowing assessments of changes in total ecosystem C stock. Planting coniferous SRF, compared to broadleaved and Eucalyptus SRF, resulted in greater accumulation of litter and overall increased soil C stock relative to agricultural controls. Though broadleaved SRF had no overall effect on soil C stock, it showed the most variable response suggesting species-specific effects and interactions with soil types. While Eucalyptus transitions induced a reduction in soil C stocks, this was not significant unless considered on a soil mass basis. Given the relatively young age and limited number of Eucalyptus plantations, it is not possible to say whether this reduction will persist in older stands. Combining estimates of C stocks from different ecosystem components (e.g., soil, aboveground biomass) reinforced the accumulation of C under coniferous SRF, and indicates generally positive effects of SRF on whole-ecosystem C. These results fill an important knowledge gap and provide data for modelling of future scenarios of LU