School of Ecosystem and Forest Sciences - Research Publications
Now showing items 1-12 of 200
Predicted consequences of increased rainfall variability on soil carbon stocks in a semiarid environment
Research on the impacts of climate change on soil organic carbon (SOC) stocks has focused on the effects of changes in average climate, but the potential effects of increased climate variability, including more frequent extreme events, remain under-examined. In this study, set in a semiarid agricultural landscape in southeastern Australia, we used the Rothamsted carbon (RothC) model to isolate the effects of interannual rainfall variability on SOC stocks over a 50 yr period. We modelled SOC trends in response to 3 scenarios that had the same 50 yr average climate but different interannual rainfall distributions: non-changing average climate, historic variability (H), and increased variability due to more frequent extreme rainfall years (XH). Relative to the non-changing average climate, RothC simulations predicted net decreases in mean SOC stocks to 50 yr of 11% under the H scenario and 13% under the XH scenario. These decreases were the result of predicted SOC decreases (and increased CO2 emissions) in extreme wet years (ca. 0.26 Mg ha(-1) yr(-1)) that were not counterbalanced by SOC increases in extreme dry years (ca. 0.11 Mg ha(-1) yr(-1)). No significant difference in mean SOC stocks at 50 yr between the H and XH scenarios was likely due to an increase in both extreme wet and counterbalancing extreme dry years in the latter. Strong negative correlations were found between annual changes in SOC stocks and rainfall. Our modelled predictions indicate the potential for extreme rainfall years to influence SOC gains and losses in semiarid environments and highlight the importance of maintaining plant inputs in these environments, particularly during extreme wet years.
Recognising fuzzy vegetation pattern: the spatial prediction of floristically defined fuzzy communities using species distribution modelling methods
QuestionPlant communities are not necessarily spatially exclusive; a point in space can exhibit properties of multiple communities. Such variation can be described using floristically defined 'fuzzy' units, however these may not be easily delineated using standard remote sensing methods. Is there value in considering communities as fuzzy? Can species distribution modelling methods be used to represent fuzzy communities spatially?LocationWestern Victoria, Australia.MethodsFuzzy communities were objectively identified from vegetation census quadrats with a cluster analysis of ordinated species data. Boosted regression trees were used to create models that defined relationships between the sampled communities and environmental predictor variables. These were applied to the mapped predictors to create maps of estimated fuzzy community membership for the entire study area.ResultsFour separate fuzzy communities were identified from the sampled vegetation data. Models were created for each community and these were effectively used to generate maps of fuzzy community membership. Individual fuzzy community maps illustrated vegetation variation that could not be discerned on a discretely classified map.ConclusionsFuzzy communities were found to represent a greater proportion of species variation than discretely classified units. Species distribution modelling methods were effective in creating independent spatial maps of each floristically defined fuzzy community; however the interpretation of these maps is more complex than with a single discrete community map.
Climate change impacts and adaptation in forest management: a review
(SPRINGER FRANCE, 2015-03-01)
Adaptation of forest management to climate change requires an understanding of the effects of climate on forests, industries and communities; prediction of how these effects might change over time; and incorporation of this knowledge into management decisions. This requires multiple forms of knowledge and new approaches to forest management decisions. Partnerships that integrate researchers from multiple disciplines with forest managers and local actors can build a shared understanding of future challenges and facilitate improved decision making in the face of climate change.Climate change presents significant potential risks to forests and challenges for forest managers. Adaptation to climate change involves monitoring and anticipating change and undertaking actions to avoid the negative consequences and to take advantage of potential benefits of those changes.This paper aimed to review recent research on climate change impacts and management options for adaptation to climate change and to identify key themes for researchers and for forest managers.The study is based on a review of literature on climate change impacts on forests and adaptation options for forest management identified in the Web of Science database, focusing on papers and reports published between 1945 and 2013.One thousand one hundred seventy-two papers were identified in the search, with the vast majority of papers published from 1986 to 2013. Seventy-six percent of papers involved assessment of climate change impacts or the sensitivity or vulnerability of forests to climate change and 11 % (130) considered adaptation. Important themes from the analysis included (i) predicting species and ecosystem responses to future climate, (ii) adaptation actions in forest management, (iii) new approaches and tools for decision making under uncertainty and stronger partnerships between researchers and practitioners and (iv) policy arrangements for adaptation in forest management.Research to support adaptation to climate change is still heavily focused on assessing impacts and vulnerability. However, more refined impact assessments are not necessarily leading to better management decisions. Multi-disciplinary research approaches are emerging that integrate traditional forest ecosystem sciences with social, economic and behavioural sciences to improve decision making. Implementing adaptation options is best achieved by building a shared understanding of future challenges among different institutions, agencies, forest owners and stakeholders. Research-policy-practice partnerships that recognise local management needs and indigenous knowledge and integrate these with climate and ecosystem science can facilitate improved decision making.
Alf Leslie: the skeptical forest economist
(Ian Ferguson, 2006)
This book reflects a critical review and synthesis of economic and related literature pertaining to forestry and forest management by a long-time forester, teacher of forest economics, UN administrator, and forest policy advisor and consultant to many governments, agencies and companies. To quote the author 'After playing around in the field of forest economics for the best part of sixty years, I wanted to sort out my ideas on the subject'.
Extraordinary drought of 2003 overrules ozone impact on adult beech trees (Fagus sylvatica)
The extraordinary drought during the summer of 2003 in Central Europe allowed to examine responses of adult beech trees (Fagus sylvatica) to co-occurring stress by soil moisture deficit and elevated O3 levels under forest conditions in southern Germany. The study comprised tree exposure to the ambient O3 regime at the site and to a twice-ambient O3 regime as released into the canopy through a free-air O3 fumigation system. Annual courses of photosynthesis (Amax), stomatal conductance (gs), electron transport rate (ETR) and chlorophyll levels were compared between 2003 and 2004, the latter year representing the humid long-term climate at the site. ETR, Amax and gs were lowered during 2003 by drought rather than ozone, whereas chlorophyll levels did not differ between the years. Radial stem increment was reduced in 2003 by drought but fully recovered during the subsequent, humid year. Comparison of AOT40, an O3 exposure-based risk index of O3 stress, and cumulative ozone uptake (COU) yielded a linear relationship throughout humid growth conditions, but a changing slope during 2003. Our findings support the hypothesis that drought protects plants from O3 injury by stomatal closure, which restricts O3 influx into leaves and decouples COU from high external ozone levels. High AOT40 erroneously suggested high O3 risk under drought. Enhanced ozone levels did not aggravate drought effects in leaves and stem.
Wood waste reduction and waste utilization
Improving wood manufacturing efficiency is complex. Material loss is occurring all along the process chain and obtaining sustainable results requires determination. There are not many quick solutions. Nevertheless, the more is achieved usually the more opportunities open up and good economic and business practices can be observed as those improvements are sustained. Developing a wood waste reduction and waste utilisation plan to prevent or minimize the production of residues should always be one of the first targets when trying to improve manufacturing efficiency. Waste minimisation and resource maximisation for manufactured products can be done everywhere from design stage to the inventory management and storage. Having the right design and using optimised cutting patterns can help avoiding situations such as over-processing raw material. Once the designing step is optimised it is possible to start implementing new practises. The degree of benefit that results from implementing waste reduction opportunities is highly dependent upon the operations. Business can usually minimize the amount of waste through proper education and training while improving their economic viability. At this stage, good communication with the entire workforce in a company is essential for a successful implementation. The quality of raw material used and the equipment at your disposition are others elements which require attention. Using better raw materials generally reduces the production of waste because it does not require as much time to sort it out and process it. Another key element in any successful improvement process is a sustainable, practical measurement system. Quality control is a simple way to know if what has been done the right way or not. Quality control is a simple tool to increase productivity and reduce waste. Monitoring a manufacturing process can ensure that the number of reject batches is kept to a minimum and help develop and maintain a maintenance schedule. Nonetheless, even the best manufacturing process creates wastes. In this case, turning wastes into valuable wood products becomes the main focus. The following pages aim to provide information on the best practises and strategies for long term business growth and increase wood manufacturing efficiency.
Improving quality of wood products - Specification on joining methods for various types of components and products to maximize wood recovery and strength of products
This report is one of the milestone reports within Activity 3.2 of ACIAR funded project “Enhancing key elements of the value chains for plantation‐grown wood in Lao PDR” which objective is to enhance the competitiveness and capacity of the Lao PDR wood processing industry through the development of an industry‐led value‐added timber market strategy. This report provides information on joining methods for various types of components and products to maximise wood recovery and strength of joints. The report does not attempt to present all the possible joints in woodworking but aims to discuss selected types of joints, commonly used in high value wood products, and highlight important factors which need to be taken into account while designing and making wooden products.