Hedgerow effects on CO2 emissions are regulated by soil type and season: implications for carbon ... more Hedgerow effects on CO2 emissions are regulated by soil type and season: implications for carbon flux dynamics in livestock-grazed pasture. Geoderma, 382, [114697].
Effective forest management is crucial to maximising the economic benefits obtained from forests.... more Effective forest management is crucial to maximising the economic benefits obtained from forests. However, the arrival of novel pests and pathogens may have a negative effect on timber values. We argue that management strategies should be calibrated to consider the effect of disease and in this paper explore the optimal rotation length of a single rotation, even-aged, plantation forest under varying disease conditions. We show that the optimal rotation length, which maximises the net present value of the forest, is reduced when disease decreases the timber value. Moreover, an increase in the rate of disease progression or the effect of disease on timber has a negative effect on the optimal rotation length. More generally, the effect of forest disease on optimal management depends in a complex way on the interaction of economic, ecological and epidemiological parameters
Thermophilization-changes in community composition towards greater relative abundances of species... more Thermophilization-changes in community composition towards greater relative abundances of species associated with warmer environments-has been described for plants and animals in many locations around the world. Disturbances of various kinds have increased rates of thermophilization in temperate sites, and this has been proposed, but not demonstrated, for some tropical environments. In this study, we tested whether disturbance by a category 4 hurricane in 1988 (Hurricane Gilbert) increased thermophilization in a Jamaican montane forest by using pre-and posthurricane data collected over four decades (1974-2014). We analysed tree species composition in permanent plots at ca 1580 m above sea level in Jamaica's Blue Mountains. There were 66 tree species with stem diameters ≥ 3 cm at breast height. We used published data on the altitudinal distribution of 62 species (94% of genetic individuals (genets)) to calculate the mean community altitude scores (MCAS) of the trees recorded in each census, as well as the MCAS of the survivors, recruits and dead trees after each decade. We found that thermophilization did occur (i.e. MCAS decreased significantly over time), and that this was due both to a decreasing MCAS of recruits through the four decades (significantly lower than expected in the last three decades) as well as a high MCAS of trees that died. Thermophilization was fastest in the post-hurricane decade, during which time there was marked and significant increase in the MCAS of dead trees; this change was above and beyond expectations of long-term successional dynamics. The rate of compositional change equates to an overall decrease in MCAS of 1.6 m yr −1 over the forty-year study period. We conclude that this Jamaican montane forest is undergoing thermophilization (likely due to rising temperature) and that the hurricane-caused disturbance accelerated thermophilization through differential mortality.
Productive forestry can deliver multifaceted climate-change mitigation benefits, including carbon... more Productive forestry can deliver multifaceted climate-change mitigation benefits, including carbon sequestration and avoided emissions from fossil-fuel-derived product substitution. However, predominantly linear use of wood substantially limits the potential mitigation contribution of forestry value-chains. Using lifecycle assessment, we show that more circular and cascading use of wood can provide immediate and sustained climate change mitigation by reducing demand for virgin wood, increasing carbon sequestration and storage, and reducing greenhouse gas emissions. Despite the clear benefits of implementing circular economy principles in forestry value-chains, we identify many functional barriers impeding the structural reorganisation needed for such complex system change. A mind-set shift towards knowledge sharing and collaboration is fundamental to transform the value-chain into an effective societal change system and lead to coherent action; with trade organisations performing imp...
Please note this a corrected version of the report published on the 23 rd June 2021 which now lis... more Please note this a corrected version of the report published on the 23 rd June 2021 which now lists the top five ranked species in Table 3.6 in the correct order (Thuja plicata and Sequoiadendron giganteum were in the wrong order in the previous version).
The Congo Basin harbours the world's second largest tropical moist forest. Here, logging mostly t... more The Congo Basin harbours the world's second largest tropical moist forest. Here, logging mostly takes place in a selective way where only few commercial tree species are extracted. The intensity of timber harvesting that can be sustained varies between forest ecosystems dependent on their resilience and productivity. Geological substrate shapes functional diversity of tree communities: recovery from deforestation and degradation tends to be slower on sandy and resource-poor soils.
Logging roads are considered to be drivers of tropical forest degradation by fragmenting the fore... more Logging roads are considered to be drivers of tropical forest degradation by fragmenting the forest and opening it for human and biological invasions. However, most secondary logging roads are abandoned after a short period of timber harvesting. Little is known about long-term forest recovery on and around these roads and about the persistence of their impacts on biodiversity. We used a time series of satellite images dating back 27 years to determine the time when roads had been abandoned after logging. We then sampled roads of different ages in seven logging concessions in South-East Cameroon. At each site we carried out plot-based vegetation inventories on a gradient from the former roadway up to 50 m into the adjacent logged forest. On the roadway we identified a clear succession trajectory, with pioneers being gradually replaced by nonpioneer-light-demanders and shade-bearers. Abundance of regenerating commercial timber species was 10-times higher on the roadway than in the clo...
Background: Forest degradation in tropical regions is often associated with roads built for selec... more Background: Forest degradation in tropical regions is often associated with roads built for selective logging. Forest areas that are not accessible by roads are considered valuable because they provide habitat that is not immediately impacted by major human activities. The protection of such Intact Forest Landscapes (IFL) is high on the biodiversity conservation agenda, leading to a motion of the Forest Stewardship Council (FSC) to better protect IFL in certified forest concessions. However, in many parts of Central Africa logging takes place at very low intensities and most roads are abandoned after few years of timber harvesting. Taking limited road persistence into account we asked: How did road networks in FSC certified concessions affect IFL? Methods: Intact forest landscapes can be conserved by retention of “roadless space”, a concept based on distance to the nearest road from any point. We used the Empty-Space Function, a general statistical tool from stochastic geometry, to ...
Afforestation is an important greenhouse gas (GHG) mitigation strategy but the efficacy of commer... more Afforestation is an important greenhouse gas (GHG) mitigation strategy but the efficacy of commercial forestry is disputed. Here, we calculate the potential GHG mitigation of a UK national planting strategy of 30,000 ha yr−1 from 2020 to 2050, using dynamic life cycle assessment. What-if scenarios vary: conifer-broadleaf composition, harvesting, product breakouts, and decarbonisation of substituted energy and materials, to estimate 100-year GHG mitigation. Here we find forest growth rate is the most important determinant of cumulative mitigation by 2120, irrespective of whether trees are harvested. A national planting strategy of commercial forest could mitigate 1.64 Pg CO2e by 2120 (cumulative), compared with 0.54–1.72 Pg CO2e for planting only conservation forests, depending on species composition. Even after heavy discounting of future product substitution credits based on industrial decarbonisation projections, GHG mitigation from harvested stands typically surpasses unharvested...
Sacred forests are an integral component of the mountainous cultural landscape of northern Greece... more Sacred forests are an integral component of the mountainous cultural landscape of northern Greece, hypothesized to be the result of both ecological processes and site-specific forest management regimes through strict religious prohibition. These practices acted as constraints on natural forest development by suppressing understory growth, while prohibition of woodcutting has preserved large trees. The aim of this study was to investigate the relative effects of physical site environment and management regimes on the structure and composition of woody plant groups in six such forests. Species rank-abundance curves, dissimilarity indices and cluster analyses were used to assess variation within and amongst the woody plant groups of the sites. Species abundance was found to be highly variable amongst the sites, with notable variation between canopy and understory layers indicating dynamic change in floristics and structure. Cluster analysis revealed four main woody plant groups statistically associated with environmental variables (aspect) and forest management (different forest prohibition regimes, and presence or absence of infrastructure). Our results indicate that tree composition is significantly associated with different prohibition regimes linked to the forests' sacred status, as well as the inherent environmental variation amongst sites. Exploring further the role of traditional management systems in shaping sacred forest structure is a relevant research path for designing effective conservation practices tailored to sacred natural sites facing cultural abandonment.
Les pistes forestières sont considérées comme des causes majeures de dégrada- tion des forêts en... more Les pistes forestières sont considérées comme des causes majeures de dégrada- tion des forêts en raison de leurs impacts directs et indirects sur le fonctionnement et la diversité des écosystèmes. Compte tenu de l’importance de l’exploitation forestière tropi- cale dans le monde, la bonne gestion de l’in- frastructure routière est cruciale pour réduire les impacts environnementaux associés à ces activités tout en réduisant les coûts des opé- rations. Notre étude visait à analyser comment la question des pistes de débardage avait été traitée dans la littérature scientifique. Des études publiées depuis 65 ans, la plupart en français, dans la revue Bois et Forêts des Tro- piques (BFT), ont été comparées à une série d’études plus récentes extraites des bases de données Scopus et Web of Knowledge. La moitié des articles BFT datent d’avant 1972, alors que les bases de données plus géné- ralistes indiquent une augmentation régu- lière, depuis cette date, du nombre d’articles publiés sur...
The effects of the spatiotemporal (> 100 years) range of hurricane disturbance intensity on tree ... more The effects of the spatiotemporal (> 100 years) range of hurricane disturbance intensity on tree diversity and density patterns are largely unknown, because data on past stand or landscape scale hurricane impacts are sometimes unavailable. We therefore reconstructed and mapped topographic exposure (a proxy to disturbance) to twelve category 2-4 hurricanes that affected the rain forests of the Blue Mountains (BM) and the John Crow Mountains (JCM) in Jamaica, over 155 years. Maps of average topographic exposure and the spatial outputs from a pixel-based polynomial regression of the cardinal directions of the tracks of past hurricanes (predictor) and past exposure (response) were then used to represent the aggregate spatiotemporal range of exposure. Next, we used data collected over the period 1974-2009 from 35, 10 x10 m nested subplots and 1991-2004 from 16, 200 m 2 circular plots for the BM and 2006-2012 from 45, 25 x 25 m plots for the JCM, and Bayesian spatiotemporal, Integrated Nested Laplace Approximation (INLA) models to determine whether stand-level (≈ 1 km 2) tree Shannon diversity and density patterns were primarily influenced by exposure to a single hurricane, the most severe hurricane or to multiple hurricanes and the duration of hurricane effects on Shannon diversity and tree density. In the BM, long-term diversity peaked at locations with intermediate values of average exposure for six hurricanes (five of which made landfall over the period 1903-1988). Short-term diversity peaked at locations that experienced significantly higher exposure situated to the south or north of the hurricane's track when the tracks were to the north or south of the island, respectively. Short-term density peaked at locations that were always highly exposed. Moreover, the influence of the most severe hurricane on diversity can last up to 101 years and the influence of the most recent hurricane (Gilbert) on diversity became evident after 16-21 years. The JCM was more susceptible to hurricanes and this diminished the influence of past hurricanes. 3 Consequently, density peaked at sites with the highest average exposure to the four most recent hurricanes (1988-2007), only one of which made landfall. If historical hurricane disturbance data are unavailable, reconstructed exposure maps can be used to provide valuable insights into the effects of past hurricanes on stand-level tree diversity and density patterns.
; phone +64 3 321 9611 Running head: Tree invasion reduces native tree diversity and richness. Hi... more ; phone +64 3 321 9611 Running head: Tree invasion reduces native tree diversity and richness. Highlights: A non-native tree, Pittosporum undulatum, is invading Jamaican montane rain forests Its invasion accelerated after an intense hurricane in 1988 and has not slowed since Local-scale tree species richness and diversity declines the more it invades The percentage of stems of trees endemic to Jamaica declines the more it invades A programme of control and removal is needed now to prevent further declines
Many have asserted that Sacred Natural Sites (SNS) play an important role in nature protection bu... more Many have asserted that Sacred Natural Sites (SNS) play an important role in nature protection but few have assessed their conservation effectiveness for different taxa. We studied sacred groves in Epirus, NW Greece, where a large number of such SNS have been identified. Based on historical, ethnographic and ecological criteria, we selected eight of these groves and matching control sites and in them we studied fungi, lichens, herbaceous plants, woody plants, nematodes, insects, bats and passerine birds. Our results reveal that the contribution of SNS to species conservation is nuanced by taxon, vegetation type and management history. We found that the sacred groves have a small conservation advantage over the corresponding control sites. More specifically, there are more distinct sets of organisms among sacred groves than among control sites, and overall biodiversity, diversity per taxonomic group, and numbers of species from the European SCI list (Species of Community Interest) are all marginally higher in them. Conservationists regard the often small size of SNS as a factor limiting their conservation value. The sizes of SNS around the globe vary greatly, from a few square meters to millions of hectares. Given that those surveyed by us (ranging from 5 to 116 ha) are at the lower end of this spectrum, the small conservation advantage that we testified becomes important. Our results provide clear evidence that even small-size SNS have considerable conservation relevance; they would contribute most to species conservation if incorporated in networks.
IOP Conference Series: Earth and Environmental Science, 2019
Consequential life cycle assessment was applied to forestry systems to evaluate the environmental... more Consequential life cycle assessment was applied to forestry systems to evaluate the environmental balance of expanding forestry onto marginal agricultural land to supply more timber for the built environment, accounting for land use effects and product substitution. Forestry expansion to supply timber buildings could mitigate UK greenhouse gas (GHG) emissions by 2.4 Gg CO2 eq. per ha of forest over 100 years, though net mitigation could be halved if beef production were displaced to Brazil. Forest thinning increases wood yields and percentage conversion of harvested wood to construction sawnwood, resulting in 5% greater net GHG mitigation compared with unthinned systems. Optimising the environmental sustainability of construction timber value chains in a circular, bio-based economy will require holistic accounting of land use (change), forestry management and complex flows of wood.
Some communities in the tropics traditionally protect natural habitats for their cultural and mat... more Some communities in the tropics traditionally protect natural habitats for their cultural and material sources, for example, in a form of sacred sites and as a communal forest. These natural habitats play an important role in biodiversity conservation which maintain through indigenous institutions that do not require involvement of conservation organizations or government bodies. These indigenous institutions regulate through customary laws and belief systems led by community elders and traditional religious leaders. Evidence from our three research sites in south and south east Asia i.e., Matiranga in eastern Bangladesh, central Maluku in eastern Indonesia, and Palawan in the Philippines are presented here to highlight on these accounts. We used different methods i.e., participatory rural appraisal, personal observations, focus groups discussion and content analysis to elicit knowledge of the communities on how they conserve and manage their forests. Our result indicates that existing indigenous forest management institutions which are closely related to local people’s belief systems served as enabling agents to manage forests. These belief systems play an important role in monitoring of forest uses, and community leaders use to impose sanctions on the transgressors. As a conclusion, reinforcing these indigenous institutions is one of the forest management alternatives to mitigate future deforestation and degradation in the tropics. Indigenous management institutions can be strengthened by 1) backing their culture and conservation activities through giving recognition at government level, 2) establishing sustainable livelihood sources for communities living around the forests that can mitigate the overexploitation.Paper summary on page 439
Introduction Over recent decades, the abundance and geographic ranges of wild ungulate species ha... more Introduction Over recent decades, the abundance and geographic ranges of wild ungulate species have expanded in many parts of Europe, including the UK. Populations are managed to mitigate their ecological impacts using interventions, such as shooting, fencing and administering contraception. Predicting how target species will respond to interventions is critical for developing sustainable, effective and efficient management strategies. However, the quantity and quality of evidence of the effects of interventions on ungulate species is unclear. To address this, we systematically mapped research on the effects of population management on wild ungulate species resident in the UK. Methods We searched four bibliographic databases, Google Scholar and nine organisational websites using search terms tested with a library of 30 relevant articles. Worldwide published peer-reviewed articles were considered, supplemented by ‘grey’ literature from UK-based sources. Three reviewers identified and...
Hedgerow effects on CO2 emissions are regulated by soil type and season: implications for carbon ... more Hedgerow effects on CO2 emissions are regulated by soil type and season: implications for carbon flux dynamics in livestock-grazed pasture. Geoderma, 382, [114697].
Effective forest management is crucial to maximising the economic benefits obtained from forests.... more Effective forest management is crucial to maximising the economic benefits obtained from forests. However, the arrival of novel pests and pathogens may have a negative effect on timber values. We argue that management strategies should be calibrated to consider the effect of disease and in this paper explore the optimal rotation length of a single rotation, even-aged, plantation forest under varying disease conditions. We show that the optimal rotation length, which maximises the net present value of the forest, is reduced when disease decreases the timber value. Moreover, an increase in the rate of disease progression or the effect of disease on timber has a negative effect on the optimal rotation length. More generally, the effect of forest disease on optimal management depends in a complex way on the interaction of economic, ecological and epidemiological parameters
Thermophilization-changes in community composition towards greater relative abundances of species... more Thermophilization-changes in community composition towards greater relative abundances of species associated with warmer environments-has been described for plants and animals in many locations around the world. Disturbances of various kinds have increased rates of thermophilization in temperate sites, and this has been proposed, but not demonstrated, for some tropical environments. In this study, we tested whether disturbance by a category 4 hurricane in 1988 (Hurricane Gilbert) increased thermophilization in a Jamaican montane forest by using pre-and posthurricane data collected over four decades (1974-2014). We analysed tree species composition in permanent plots at ca 1580 m above sea level in Jamaica's Blue Mountains. There were 66 tree species with stem diameters ≥ 3 cm at breast height. We used published data on the altitudinal distribution of 62 species (94% of genetic individuals (genets)) to calculate the mean community altitude scores (MCAS) of the trees recorded in each census, as well as the MCAS of the survivors, recruits and dead trees after each decade. We found that thermophilization did occur (i.e. MCAS decreased significantly over time), and that this was due both to a decreasing MCAS of recruits through the four decades (significantly lower than expected in the last three decades) as well as a high MCAS of trees that died. Thermophilization was fastest in the post-hurricane decade, during which time there was marked and significant increase in the MCAS of dead trees; this change was above and beyond expectations of long-term successional dynamics. The rate of compositional change equates to an overall decrease in MCAS of 1.6 m yr −1 over the forty-year study period. We conclude that this Jamaican montane forest is undergoing thermophilization (likely due to rising temperature) and that the hurricane-caused disturbance accelerated thermophilization through differential mortality.
Productive forestry can deliver multifaceted climate-change mitigation benefits, including carbon... more Productive forestry can deliver multifaceted climate-change mitigation benefits, including carbon sequestration and avoided emissions from fossil-fuel-derived product substitution. However, predominantly linear use of wood substantially limits the potential mitigation contribution of forestry value-chains. Using lifecycle assessment, we show that more circular and cascading use of wood can provide immediate and sustained climate change mitigation by reducing demand for virgin wood, increasing carbon sequestration and storage, and reducing greenhouse gas emissions. Despite the clear benefits of implementing circular economy principles in forestry value-chains, we identify many functional barriers impeding the structural reorganisation needed for such complex system change. A mind-set shift towards knowledge sharing and collaboration is fundamental to transform the value-chain into an effective societal change system and lead to coherent action; with trade organisations performing imp...
Please note this a corrected version of the report published on the 23 rd June 2021 which now lis... more Please note this a corrected version of the report published on the 23 rd June 2021 which now lists the top five ranked species in Table 3.6 in the correct order (Thuja plicata and Sequoiadendron giganteum were in the wrong order in the previous version).
The Congo Basin harbours the world's second largest tropical moist forest. Here, logging mostly t... more The Congo Basin harbours the world's second largest tropical moist forest. Here, logging mostly takes place in a selective way where only few commercial tree species are extracted. The intensity of timber harvesting that can be sustained varies between forest ecosystems dependent on their resilience and productivity. Geological substrate shapes functional diversity of tree communities: recovery from deforestation and degradation tends to be slower on sandy and resource-poor soils.
Logging roads are considered to be drivers of tropical forest degradation by fragmenting the fore... more Logging roads are considered to be drivers of tropical forest degradation by fragmenting the forest and opening it for human and biological invasions. However, most secondary logging roads are abandoned after a short period of timber harvesting. Little is known about long-term forest recovery on and around these roads and about the persistence of their impacts on biodiversity. We used a time series of satellite images dating back 27 years to determine the time when roads had been abandoned after logging. We then sampled roads of different ages in seven logging concessions in South-East Cameroon. At each site we carried out plot-based vegetation inventories on a gradient from the former roadway up to 50 m into the adjacent logged forest. On the roadway we identified a clear succession trajectory, with pioneers being gradually replaced by nonpioneer-light-demanders and shade-bearers. Abundance of regenerating commercial timber species was 10-times higher on the roadway than in the clo...
Background: Forest degradation in tropical regions is often associated with roads built for selec... more Background: Forest degradation in tropical regions is often associated with roads built for selective logging. Forest areas that are not accessible by roads are considered valuable because they provide habitat that is not immediately impacted by major human activities. The protection of such Intact Forest Landscapes (IFL) is high on the biodiversity conservation agenda, leading to a motion of the Forest Stewardship Council (FSC) to better protect IFL in certified forest concessions. However, in many parts of Central Africa logging takes place at very low intensities and most roads are abandoned after few years of timber harvesting. Taking limited road persistence into account we asked: How did road networks in FSC certified concessions affect IFL? Methods: Intact forest landscapes can be conserved by retention of “roadless space”, a concept based on distance to the nearest road from any point. We used the Empty-Space Function, a general statistical tool from stochastic geometry, to ...
Afforestation is an important greenhouse gas (GHG) mitigation strategy but the efficacy of commer... more Afforestation is an important greenhouse gas (GHG) mitigation strategy but the efficacy of commercial forestry is disputed. Here, we calculate the potential GHG mitigation of a UK national planting strategy of 30,000 ha yr−1 from 2020 to 2050, using dynamic life cycle assessment. What-if scenarios vary: conifer-broadleaf composition, harvesting, product breakouts, and decarbonisation of substituted energy and materials, to estimate 100-year GHG mitigation. Here we find forest growth rate is the most important determinant of cumulative mitigation by 2120, irrespective of whether trees are harvested. A national planting strategy of commercial forest could mitigate 1.64 Pg CO2e by 2120 (cumulative), compared with 0.54–1.72 Pg CO2e for planting only conservation forests, depending on species composition. Even after heavy discounting of future product substitution credits based on industrial decarbonisation projections, GHG mitigation from harvested stands typically surpasses unharvested...
Sacred forests are an integral component of the mountainous cultural landscape of northern Greece... more Sacred forests are an integral component of the mountainous cultural landscape of northern Greece, hypothesized to be the result of both ecological processes and site-specific forest management regimes through strict religious prohibition. These practices acted as constraints on natural forest development by suppressing understory growth, while prohibition of woodcutting has preserved large trees. The aim of this study was to investigate the relative effects of physical site environment and management regimes on the structure and composition of woody plant groups in six such forests. Species rank-abundance curves, dissimilarity indices and cluster analyses were used to assess variation within and amongst the woody plant groups of the sites. Species abundance was found to be highly variable amongst the sites, with notable variation between canopy and understory layers indicating dynamic change in floristics and structure. Cluster analysis revealed four main woody plant groups statistically associated with environmental variables (aspect) and forest management (different forest prohibition regimes, and presence or absence of infrastructure). Our results indicate that tree composition is significantly associated with different prohibition regimes linked to the forests' sacred status, as well as the inherent environmental variation amongst sites. Exploring further the role of traditional management systems in shaping sacred forest structure is a relevant research path for designing effective conservation practices tailored to sacred natural sites facing cultural abandonment.
Les pistes forestières sont considérées comme des causes majeures de dégrada- tion des forêts en... more Les pistes forestières sont considérées comme des causes majeures de dégrada- tion des forêts en raison de leurs impacts directs et indirects sur le fonctionnement et la diversité des écosystèmes. Compte tenu de l’importance de l’exploitation forestière tropi- cale dans le monde, la bonne gestion de l’in- frastructure routière est cruciale pour réduire les impacts environnementaux associés à ces activités tout en réduisant les coûts des opé- rations. Notre étude visait à analyser comment la question des pistes de débardage avait été traitée dans la littérature scientifique. Des études publiées depuis 65 ans, la plupart en français, dans la revue Bois et Forêts des Tro- piques (BFT), ont été comparées à une série d’études plus récentes extraites des bases de données Scopus et Web of Knowledge. La moitié des articles BFT datent d’avant 1972, alors que les bases de données plus géné- ralistes indiquent une augmentation régu- lière, depuis cette date, du nombre d’articles publiés sur...
The effects of the spatiotemporal (> 100 years) range of hurricane disturbance intensity on tree ... more The effects of the spatiotemporal (> 100 years) range of hurricane disturbance intensity on tree diversity and density patterns are largely unknown, because data on past stand or landscape scale hurricane impacts are sometimes unavailable. We therefore reconstructed and mapped topographic exposure (a proxy to disturbance) to twelve category 2-4 hurricanes that affected the rain forests of the Blue Mountains (BM) and the John Crow Mountains (JCM) in Jamaica, over 155 years. Maps of average topographic exposure and the spatial outputs from a pixel-based polynomial regression of the cardinal directions of the tracks of past hurricanes (predictor) and past exposure (response) were then used to represent the aggregate spatiotemporal range of exposure. Next, we used data collected over the period 1974-2009 from 35, 10 x10 m nested subplots and 1991-2004 from 16, 200 m 2 circular plots for the BM and 2006-2012 from 45, 25 x 25 m plots for the JCM, and Bayesian spatiotemporal, Integrated Nested Laplace Approximation (INLA) models to determine whether stand-level (≈ 1 km 2) tree Shannon diversity and density patterns were primarily influenced by exposure to a single hurricane, the most severe hurricane or to multiple hurricanes and the duration of hurricane effects on Shannon diversity and tree density. In the BM, long-term diversity peaked at locations with intermediate values of average exposure for six hurricanes (five of which made landfall over the period 1903-1988). Short-term diversity peaked at locations that experienced significantly higher exposure situated to the south or north of the hurricane's track when the tracks were to the north or south of the island, respectively. Short-term density peaked at locations that were always highly exposed. Moreover, the influence of the most severe hurricane on diversity can last up to 101 years and the influence of the most recent hurricane (Gilbert) on diversity became evident after 16-21 years. The JCM was more susceptible to hurricanes and this diminished the influence of past hurricanes. 3 Consequently, density peaked at sites with the highest average exposure to the four most recent hurricanes (1988-2007), only one of which made landfall. If historical hurricane disturbance data are unavailable, reconstructed exposure maps can be used to provide valuable insights into the effects of past hurricanes on stand-level tree diversity and density patterns.
; phone +64 3 321 9611 Running head: Tree invasion reduces native tree diversity and richness. Hi... more ; phone +64 3 321 9611 Running head: Tree invasion reduces native tree diversity and richness. Highlights: A non-native tree, Pittosporum undulatum, is invading Jamaican montane rain forests Its invasion accelerated after an intense hurricane in 1988 and has not slowed since Local-scale tree species richness and diversity declines the more it invades The percentage of stems of trees endemic to Jamaica declines the more it invades A programme of control and removal is needed now to prevent further declines
Many have asserted that Sacred Natural Sites (SNS) play an important role in nature protection bu... more Many have asserted that Sacred Natural Sites (SNS) play an important role in nature protection but few have assessed their conservation effectiveness for different taxa. We studied sacred groves in Epirus, NW Greece, where a large number of such SNS have been identified. Based on historical, ethnographic and ecological criteria, we selected eight of these groves and matching control sites and in them we studied fungi, lichens, herbaceous plants, woody plants, nematodes, insects, bats and passerine birds. Our results reveal that the contribution of SNS to species conservation is nuanced by taxon, vegetation type and management history. We found that the sacred groves have a small conservation advantage over the corresponding control sites. More specifically, there are more distinct sets of organisms among sacred groves than among control sites, and overall biodiversity, diversity per taxonomic group, and numbers of species from the European SCI list (Species of Community Interest) are all marginally higher in them. Conservationists regard the often small size of SNS as a factor limiting their conservation value. The sizes of SNS around the globe vary greatly, from a few square meters to millions of hectares. Given that those surveyed by us (ranging from 5 to 116 ha) are at the lower end of this spectrum, the small conservation advantage that we testified becomes important. Our results provide clear evidence that even small-size SNS have considerable conservation relevance; they would contribute most to species conservation if incorporated in networks.
IOP Conference Series: Earth and Environmental Science, 2019
Consequential life cycle assessment was applied to forestry systems to evaluate the environmental... more Consequential life cycle assessment was applied to forestry systems to evaluate the environmental balance of expanding forestry onto marginal agricultural land to supply more timber for the built environment, accounting for land use effects and product substitution. Forestry expansion to supply timber buildings could mitigate UK greenhouse gas (GHG) emissions by 2.4 Gg CO2 eq. per ha of forest over 100 years, though net mitigation could be halved if beef production were displaced to Brazil. Forest thinning increases wood yields and percentage conversion of harvested wood to construction sawnwood, resulting in 5% greater net GHG mitigation compared with unthinned systems. Optimising the environmental sustainability of construction timber value chains in a circular, bio-based economy will require holistic accounting of land use (change), forestry management and complex flows of wood.
Some communities in the tropics traditionally protect natural habitats for their cultural and mat... more Some communities in the tropics traditionally protect natural habitats for their cultural and material sources, for example, in a form of sacred sites and as a communal forest. These natural habitats play an important role in biodiversity conservation which maintain through indigenous institutions that do not require involvement of conservation organizations or government bodies. These indigenous institutions regulate through customary laws and belief systems led by community elders and traditional religious leaders. Evidence from our three research sites in south and south east Asia i.e., Matiranga in eastern Bangladesh, central Maluku in eastern Indonesia, and Palawan in the Philippines are presented here to highlight on these accounts. We used different methods i.e., participatory rural appraisal, personal observations, focus groups discussion and content analysis to elicit knowledge of the communities on how they conserve and manage their forests. Our result indicates that existing indigenous forest management institutions which are closely related to local people’s belief systems served as enabling agents to manage forests. These belief systems play an important role in monitoring of forest uses, and community leaders use to impose sanctions on the transgressors. As a conclusion, reinforcing these indigenous institutions is one of the forest management alternatives to mitigate future deforestation and degradation in the tropics. Indigenous management institutions can be strengthened by 1) backing their culture and conservation activities through giving recognition at government level, 2) establishing sustainable livelihood sources for communities living around the forests that can mitigate the overexploitation.Paper summary on page 439
Introduction Over recent decades, the abundance and geographic ranges of wild ungulate species ha... more Introduction Over recent decades, the abundance and geographic ranges of wild ungulate species have expanded in many parts of Europe, including the UK. Populations are managed to mitigate their ecological impacts using interventions, such as shooting, fencing and administering contraception. Predicting how target species will respond to interventions is critical for developing sustainable, effective and efficient management strategies. However, the quantity and quality of evidence of the effects of interventions on ungulate species is unclear. To address this, we systematically mapped research on the effects of population management on wild ungulate species resident in the UK. Methods We searched four bibliographic databases, Google Scholar and nine organisational websites using search terms tested with a library of 30 relevant articles. Worldwide published peer-reviewed articles were considered, supplemented by ‘grey’ literature from UK-based sources. Three reviewers identified and...
Uploads
Papers by John Healey