Forestry Commission England

Abstract The oak processionary moth (OPM; Thaumetopoea processionea ) (Linnaeus, 1778) (Lepidoptera: Notodontidae) is an invasive pest across northern Europe. In the United Kingdom, it threatens biodiversity and public health through defoliation caused by numerical dominance of infested trees and the shedding of harmful urticating hairs. Its spread from the current established zone in and around Greater London combined with the rising cost of chemical control show an urgent need for alternative sustainable management. Current alternative strategies revolve around conservation biocontrol using the larval parasitoid Carcelia iliaca (Ratzeburg, 1840) (Diptera: Tachinidae), which is a successful parasitoid reaching parasitism rates of ~80%. However, fundamental biological information regarding C. iliaca is still missing, meaning that creating evidence‐based policies is impossible. Here, we apply a recently developed diagnostic assay to detect C. iliaca from OPM larval tissue to assess parasitism rates across the Greater London area. Samples were collected from 12 sites across two field seasons with 1624 caterpillars collected in 2021 and 2239 caterpillars collected in 2022. Parasitism rates showed a higher average in Year 1 (60.8% [±2]) than Year 2 (34.0% [±2%]), with wide range across sites in both years (Year 1, 50%–69%, Year 2, 26%–53%). However, these data show no spatial trend in parasitism rate despite the sites surveyed being composed of a range of habitat types. We evaluate the effectiveness of the diagnostic assay and discuss the wider implications of long‐term monitoring of parasitoids and the need to identify interactions to better inform conservation biocontrol management strategies.

Abstract Existing research on the social and cultural (S&C) values of treescapes tends to be limited in scope, for example to recreation, aesthetic or health values, and much is primarily qualitative, which provides rich detail but does not lend itself easily to incorporation into decision‐making. Having a way to quantify the range of S&C values associated with treescapes is important if decision‐makers are to effectively take these into account. This issue is particularly important currently with ambitious plans to increase tree cover alongside growing threats to treescapes from climate change and tree pests and diseases.This paper outlines the development of a new composite measure to quantify the S&C values associated with treescapes. The development of the measure resulted in a set of 19 statements across six categories of S&C value.We present results from using the measure in a survey with a representative sample of 5000 people across England together with the results of a factor analysis, which suggests a way to simplify the measure into five statements.We examine the measure through the lens of relational values and suggest that a majority of the values in our measure are relational.Policy implications. The composite measure can be used by decision‐makers looking to develop their evidence base regarding the value of treescapes in their area, or for exploring the impact of tree pests and diseases. It has already been used by more than one local authority in England. While data collection was limited to England, we suggest that the measure is applicable across a wider range of countries.Read the freePlain Language Summaryfor this article on the Journal blog.

Vegetation is an essential component of the terrestrial ecosystem and has changed significantly over the last two decades in the Northwestern Highlands of Ethiopia. However, previous studies have focused on the detection of bitemporal change and lacked the incorporation of entire vegetation time series changes, which are considered significant indicators of ecosystem conditions. The Normalized Difference Vegetation Index (NDVI) time series dataset from the Moderate-Resolution Imaging Spectroradiometer (MODIS) is an efficient method for analyzing the dynamics of vegetation change over a lengthy period using remote sensing techniques. This study aimed to utilize time series satellite data to detect vegetation changes from 2000 to 2020 and investigate their links with ecosystem conditions. The time-series satellite processing package (TIMESAT) was used to estimate the seasonal parameter values of NDVI and their correlation across the seasons during the study period. Break Detection for Additive Season and Trend (BFAST) was applied to identify the year of breakpoints, the direction of magnitude, and the number of breakpoints. The results were reported, analyzed, and linked to ecosystem conditions. The overall trend in the study area increased from 0.58 (2000–2004) to 0.65 (2015–2020). As a result, ecosystem condition indicators such as peak value (PV), base value (BV), amplitude (Amp), and large integral (LI) exhibited significant positive trends, particularly for Acacia decurrens plantations, Eucalyptus plantations, and grasslands, but phenology indicator parameters such as start of season (SOS), end of season (EOS), and length of season (LOS) did not show significant trends for almost any vegetation type. The most abrupt changes were recorded in 2015 (24.7%), 2012 (18.6%), and 2014 (9.8%). Approximately 30% of the vegetation changes were positive in magnitude. The results of this study imply that there was an improvement in the ecosystem’s condition following the establishment of the Acacia decurrens plantation. The findings are considered relevant inputs for policymakers and serve as an initial stage for the assessment of the other environmental and climatic implications of Acacia decurrens plantations at the local scale.

The study aimed at assessing the common constraints that affect the enforcement of small-scale mining laws and regulations which have created a vacuum for illegal operators to infiltrate the space with the associated environmental and social cost implications. Underpinned by the institutional theory, the study analyzes from existing theoretical and empirical studies to assess why institutions and agencies on artisanal and small-scale mining find it difficult to clamp down on illegal gold extractive activities. Retrospective literature analysis was the main method employed by the study. A synthesis from the review suggests that key challenges revolve around poor allocation of resources, poor collaboration among multiple levels and sectors, protection rackets by powerful beings in society, connivance of some traditional authorities and members, poverty, green squeezing, and cumbersome nature of ASM licensing process in Ghana. The study contends on the one hand that laws, policies, and regulations are only as good as their enforcement; whilst on the other hand, enforcement is only as good as the laws and regulations formulated in the first place. The study discusses five policy suggestions that will go a long way to help enforcement of ASM policies and institutions in Ghana.

Processos inovadores de aceleração do fl orescimento de espécies de Eucalyptus por top graftings (enxertias de topo), incluem a possibilidade de redução do tempo dos ciclos no melhoramento fl orestal. Esta permite a produção de linhagens fl orestais e torna o uso da Seleção Genômica Ampla operacional. O objetivo foi estabelecer metodologias para a realização de top graftings em genótipos autofecundados e de mudas juvenis, de Eucalyptus, visando a indução precoce de fl orescimento. As avaliações dos top graftings foram realizadas a cada 3 meses após as enxertias, quanto à sobrevivência, em variáveis de crescimento e fl orescimento. As análises estatísticas foram realizadas utilizando-se o REML/BLUP e o o teste Scott-Knott. Desta forma, foram determinados os efeitos dos tratamentos sobre as variáveis avaliadas. Constatamos que a predisposição dos top graftings à enxertia varia de acordo com o material genético utilizado. A quantidade de botões fl orais e frutos produzidos pelos top graftings foi satisfatória para atestar sobre a efi ciência da metodologia. As últimas avaliações realizadas demonstraram a capacidade de top graftings produzirem mais de 4 mil botões fl orais em um único enxerto. O fl orescimento permitiu que os polens fossem coletados, para serem utilizados em cruzamentos ou avanço de autofecundação nessas plantas S1 pela CENIBRA. Levando em consideração o desempenho dos enxertos para fl orescimento, a melhor época para realização de top grafi tings varia de acordo com a sua fi nalidade, sendo que para a enxertia de genótipos autofecundados, o ideal é a época de 3 meses antes do fl orescimento. Já para a enxertia de mudas jovens, os top graftings de 6 meses antes apresentam melhores resultados para fl orescimento e crescimento de área de copa. Considerando as duas épocas de enxertia, a aplicação de paclobutrazol favorece o fl orescimento ainda mais precoce dos top graftings. Concluímos por fi m, que a técnica é viável para Eucalyptus e pode ser replicada para as espécies do gênero, seguindo os procedimentos recomendados.

The UK is vulnerable to wildfire, and vulnerability is likely to increase due to climate change. Whilst the risk is small compared with many other countries, recent fires have raised awareness and highlighted the potential for environmental damage and loss of property and key infrastructure. Most UK wildfires are a result of inadvertent or deliberate human action, but the environmental conditions depend on antecedent and current weather. This paper presents projections of the effects of climate change on UK wildfire danger, using a version of an operational fire danger model, UKCP18 climate projections representing low and high emissions, and several indicators of fire danger. Fire danger will increase across the whole of the UK, but the extent and variability in change varies with indicator. The absolute danger now and into the future is greatest in the south and east (the average number of danger days increases 3–4 times by the 2080s), but danger increases further north from a lower base. The variation in change across the UK for indicators based on absolute thresholds is determined by how often those thresholds are exceeded now, whilst the (lesser) variability in percentile-based indicators reflects variability in the projected change in climate. Half of the increase in danger is due to increased temperature, and most of the rest is due to projected reductions in relative humidity. Uncertainty in the magnitude of the change is due to uncertainty in changes in temperature, relative humidity, and rainfall, and there is a large difference between two of the UKCP18 climate model ensembles. Reducing emissions to levels consistent with achieving international climate policy targets significantly reduces, but does not eliminate, the increase in fire danger. The results imply that greater attention needs to be given to wildfire danger in both emergency and spatial planning, and in the development of guidelines for activities that may trigger fires. They suggest the need for the development of a fire danger system more tailored to UK conditions, and the combination of fire danger modelling with projections of sources of ignition to better estimate the change in wildfire risk.

Abstract The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a highly destructive primary pest of ash (Fraxinus sp., Oleaceae) trees outside of its native range. Ash is an important component of many ecosystems and its loss would be detrimental to both the economy and the environment. The present study aimed to improve our understanding of the effectiveness of green sticky prism traps baited with host kairomone and insect pheromone lures for A. planipennis and to collect data for modelling the range of attraction of the pheromone (3Z)‐dodecen‐12‐olide [(3Z)‐lactone]. Traps were deployed over a single flight season in urban locations of Ontario, Canada, with low densities of EAB. Traps were placed in pairs of trees separated by not more than 25 m. All traps contained the host kairomone, (3Z)‐hexenol, with the remaining half in each pairing additionally baited with (3Z)‐lactone pheromone. Both lure types were highly effective in capturing EAB, with >90% detection rates overall. However, traps baited with the lactone pheromone and host volatile lures doubled trap captures of EAB over distances of at least 25 m from the nearest traps baited with only host volatiles. Although the baseline detection rate of traps containing (3Z)‐hexenol alone is not significantly reduced compared with traps containing (3Z)‐lactone, the overall trap effectiveness is significantly increased when (3Z)‐lactone is present. The implications for the use of (3Z)‐lactone at 3 mg per septum dose in an early warning trapping system are discussed. Trap layout methods and risk‐based analysis models can now be further refined by including these data about the attractive range of lures and their behaviour in different plot environments.

Background. Uncertainty about climate change impacts on forests can hinder mitigation and adaptation actions. Scientific enquiry typically involves assessments of uncertainties, yet different uncertainty components emerge in different studies. Consequently, inconsistent understanding of uncertainty among different climate impact studies (from the impact analysis to implementing solutions) can be an additional reason for delaying action. In this review we (a) expanded existing uncertainty assessment frameworks into one harmonised framework for characterizing uncertainty, (b) used this framework to identify and classify uncertainties in climate change impacts studies on forests, and (c) summarised the uncertainty assessment methods applied in those studies. Methods. We systematically reviewed climate change impact studies published between 1994 and 2016. We separated these studies into those generating information about climate change impacts on forests using models –‘modelling studies’, and those that used this information to design management actions—‘decision-making studies’. We classified uncertainty across three dimensions: nature, level, and location, which can be further categorised into specific uncertainty types. Results. We found that different uncertainties prevail in modelling versus decision-making studies. Epistemic uncertainty is the most common nature of uncertainty covered by both types of studies, whereas ambiguity plays a pronounced role only in decision-making studies. Modelling studies equally investigate all levels of uncertainty, whereas decision-making studies mainly address scenario uncertainty and recognised ignorance. Finally, the main location of uncertainty for both modelling and decision-making studies is within the driving forces—representing, e.g. socioeconomic or policy changes. The most frequently used methods to assess uncertainty are expert elicitation, sensitivity and scenario analysis, but a full suite of methods exists that seems currently underutilized. Discussion & Synthesis. The misalignment of uncertainty types addressed by modelling and decision-making studies may complicate adaptation actions early in the implementation pathway. Furthermore, these differences can be a potential barrier for communicating research findings to decision-makers.