Julia Mcmorrow

Decline of forest area in Sabah, Malaysia: relationship to state policies, land code and land capability

Abstract Forest decline in Sabah has resulted from state policies operating within the federal context. Approximately two-thirds of Sabahs natural forest remains but estimates vary with the data source. Logging and shifting cultivation have degraded forest quality but commercial estate agriculture, especially oil palm, is now the major cause of forest loss, aided by Sabahs land tenure code and the ethnic equality and modernisation agendas of national and state agriculture policy. The pattern of forest decline is explained by partitioning of the land resource between gazetted Forest Reserves and land alienated to agriculture, guided by the 1976 land capability classification.

Linear regression modelling for the estimation of oil palm age from Landsat TM

This paper investigates the accuracy with which the age since field planting of oil palm (Elaeis guineensis Jacq.) can be estimated from Landsat Thematic Mapper (TM) radiance at pixel and stand scales. The study site, a commercial plantation 30 km south-east of Kuala Lumpur in Selangor, Malaysia, consisted of even-aged blocks from 4 to 21 years old. Spectral data were the six reflective TM bands and three spectral indices. Nonlinear negative relationships between spectral variables and age are compared to published trends in leaf area, stem height and per cent canopy cover for oil palm and other tree plantations. Correlation coefficients between log age and log radiance are moderate and highly significant (p<0.01) for bands 2-5 and 7 (-0.214 to-0.776) at the pixel scale, and increase at the stand scale (r 2=0.985 for log band 5, p<0.01). Relationships are strongest for the mid-infrared bands, especially band 5 (r 2=0.585, p <0.01) and the infrared index (IRI), a normalized difference index of bands 4 and 5 (r 2= 0.48, p<0.01). Direct and inverse linear regression models for log age with log band and log age with IRI squared (IRIsq) were constructed at both scales. Equivalent age was estimated from the models using independent test sets for differing scales and degrees of aggregation of the age classes. Single age classes cannot be estimated accurately at the pixel or stand scales; the lowest RMS error was obtained from the direct model using all bands (RMS error=3.9 years at pixel scale, 2.7 at stand scale). A posteriori aggregation into generalized age classes (<5, 6-10, 11-15, 16-21 years) improved the RMS error but the results were still unacceptably high (2.2, 2.3, 2.7, 6.0 years respectively for direct model 3 using all bands). Acceptable RMS errors down to 0.58 years were obtained for models using IRIsq with generalized age classes developed and applied at the stand scale when variations in ground cover and other variables were averaged out. The spatial pattern of error in equivalent age deserves investigation for precision crop management.

The role of fire in UK peatland and moorland management: the need for informed, unbiased debate

Fire has been used for centuries to generate and manage some of the UKs cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions. This article is part of the themed issue ‘The interaction of fire and mankind’.

Forecasting the outbreak of moorland wildfires in the English Peak District

Warmer, drier summers brought by climate change increase the potential risk of wildfires on the moorland of the Peak District of northern England. Fires are costly to fight, damage the ecosystem, harm water catchments, cause erosion scars and disrupt transport. Fires release carbon dioxide to the atmosphere. Accurate forecasts of the timing of fires help deployment of fire fighting resources. A probit model is used to assess the chance of fires at different times of the year, days of the week and under various weather conditions. Current and past rainfall damp fire risk. The likelihood of fire increases with maximum temperature. Dry spells or recent fire activity also signal extra fire hazard. Certain days are fire prone due to visitors and some months of the year are more risky reflecting the changing flammability of moorland vegetation. The model back-predicts earlier fires during a hot dry summer. The impact of climate change on fire incidence is not straightforward. Risks may be reduced if wetter winters and earlier onset of spring add to plant moisture content. Yet a warm spring increases biomass and potential fuel load in summer. Climate change may cause the timing of moorland wildfires to shift from a damper and more verdant spring to drought-stressed summer.

Changes to climate and visitor behaviour: implications for vulnerable landscapes in the North West region of England.

Many high quality landscapes can be found in the North West region of England, including those of international significance such as the Lake District National Park. These natural assets are recognised by the regional tourism strategy as particularly important, as they are a major determinant for visitors within, and to, the region. However, with the strategy geared towards increasing visitor numbers, there is a substantial challenge to be faced in the future: how to maintain the quality of an environment that is under combined pressure from both visitor numbers and climate change? Focusing on two landscape types considered to be the most vulnerable to a changing climate, the coastal zone and the uplands, this paper presents ‘downscaled’ climate change scenarios, and provides an assessment of how a combination of climate and non-climate factors are likely to impact these vulnerable landscapes in the future. The case study analysis is largely drawn from a series of ‘risk’ workshops held with key regional stakeholders.

Empirical Modelling of Vegetation Abundance from Airborne Hyperspectral Data for Upland Peatland Restoration Monitoring

Peatlands are important terrestrial carbon stores. Restoration of degraded peatlands to restore ecosystem services is a major area of conservation effort. Monitoring is crucial to judge the success of this restoration. Remote sensing is a potential tool to provide landscape-scale information on the habitat condition. Using an empirical modelling approach, this paper aims to use airborne hyperspectral image data with ground vegetation survey data to model vegetation abundance for a degraded upland blanket bog in the United Kingdom (UK), which is undergoing restoration. A predictive model for vegetation abundance of Plant Functional Types (PFT) was produced using a Partial Least Squares Regression (PLSR) and applied to the whole restoration site. A sensitivity test on the relationships between spectral data and vegetation abundance at PFT and single species level confirmed that PFT was the correct scale for analysis. The PLSR modelling allows selection of variables based upon the weighted regression coefficient of the individual spectral bands, showing which bands have the most influence on the model. These results suggest that the SWIR has less value for monitoring peatland vegetation from hyperspectral images than initially predicted. RMSE values for the validation data range between 10% and 16% cover, indicating that the models can be used as an operational tool, considering the subjective nature of existing vegetation survey results. These predicted coverage images are the first quantitative landscape scale monitoring results to be produced for the site. High resolution hyperspectral mapping of PFTs has the potential to assess recovery of peatland systems at landscape scale for the first time.

Hyperspectral indices for characterizing upland peat composition

The erosion of blanket peat is a major environmental issue in the UK. Maps of erosion extent and peat composition, especially humification and moisture content, would aid our understanding of the erosion process and provide information for management decisions. HyMap images, acquired as part of the SAR and Hyperspectral Airborne Campaign (SHAC), were used to test candidate indices of peat composition for eroded blanket peat in the southern Pennines. Peat physical properties, including moisture content and degree of humification (measured as transmission), were derived in the laboratory and related to the remotely sensed data. Strong correlations were found between HyMap SWIR reflectance and transmission, but other peat physical properties were not significantly correlated. Spectral indices were calculated to express the depth of cellulose, lignin and water absorption features. Strong positive correlations were found between transmission and an adjusted cellulose absorption index (CAI), r 0.71, and the gradient of its shoulders between 2020 and 2200 nm, r 0.89. Other indices also performed well. Normalized indices performed better because they allowed for differences in brightness. Higher moisture content in poorly humified peats may have reinforced the effect of deeper ligno-celluloic absorptions, but further sampling is required to test this. The results suggest the potential for hyperspectral remote sensing to provide information on surface peat composition across large areas.

Relation of oil palm spectral response to stand age

Abstract Relative radiance recorded by the Landsat Thematic Mapper (TM) for l–1O-year-old plantations of oil palm (Elaeis guineensis Jacq.) in Sabah, Malaysia, was negatively correlated with stand age. Remotely sensed response is determined by biophysical variables related to age since field planting, notably leaf area, canopy architecture and progressive masking of ground cover vegetation. The relation was asymptotic. Age and age-related variables will be most accurately inferred from TM data for stands under 5-years old, especially using short wave infrared and thermal bands. Narrower age classes will be required to represent younger stands in image classification.

Wildfire policy and management in England: an evolving response from fire and rescue services, forestry and cross-sector groups

Severe wildfires are an intermittent problem in England. The paper presents the first analysis of wildfire policy, showing its halting evolution over two decades. First efforts to coordinate wildfire management came from local fire operation groups, where stakeholders such as fire services, land owners and amenity groups shared knowledge and equipment to tackle the problem. A variety of structures and informal management solutions emerged in response to local needs. Knowledge of wildfire accumulated within regional and national wildfire forums and academic networks. Only later did the need for central emergency planning and the response to climate change produce a national policy response. Fire statistics have allowed wildfires to be spatially evidenced on a national scale only since 2009. National awareness of wildfire was spurred by the 2011 fire season, and the high-impact Swinley Forest fire, which threatened critical infrastructure and communities within 50 miles of London. Severe wildfire was included in the National Risk Register for the first time in 2013. Cross-sector approaches to wildfire proved difficult as government responsibility is fragmented along the hazard chain. Stakeholders such as the Forestry Commission pioneered good practice in adaptive land management to build fire resilience into UK forests. The grass-roots evolution of participatory solutions has also been a key enabling process. A coordinated policy is now needed to identify best practice and to promote understanding of the role of fire in the ecosystem. This article is part of a themed issue ‘The interaction of fire and mankind’.

Living on a flammable planet: interdisciplinary, cross-scalar and varied cultural lessons, prospects and challenges.

Living with fire is a challenge for human communities because they are influenced by socio-economic, political, ecological and climatic processes at various spatial and temporal scales. Over the course of 2 days, the authors discussed how communities could live with fire challenges at local, national and transnational scales. Exploiting our diverse, international and interdisciplinary expertise, we outline generalizable properties of fire-adaptive communities in varied settings where cultural knowledge of fire is rich and diverse. At the national scale, we discussed policy and management challenges for countries that have diminishing fire knowledge, but for whom global climate change will bring new fire problems. Finally, we assessed major fire challenges that transcend national political boundaries, including the health burden of smoke plumes and the climate consequences of wildfires. It is clear that to best address the broad range of fire problems, a holistic wildfire scholarship must develop common agreement in working terms and build across disciplines. We must also communicate our understanding of fire and its importance to the media, politicians and the general public. This article is part of the themed issue ‘The interaction of fire and mankind’.