Eucalyptus 2018 17-21 September 2018, Le Corum, Montpellier - France
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Eucalyptus 2018 17-21 September 2018, Le Corum, Montpellier - France Eucalyptus 2018 Managing Eucalyptus plantations under global changes Abstracts Book ISBN : 978-2-87614-743-0 EAN : 9782876147430 Foreword Eucalyptus trees cover about 20 million hectares in more than 90 countries around the world with major centers in Brazil (5.7 m ha), India (3.9 m ha) and China (4.5 m ha). Eucalypts are widely grown in commercial plantations to produce raw material for the industry (pulp and paper, charcoal, sawn timber, wood panels) but also in small woodlots for the production of firewood and charcoal for domestic uses. The considerable expansion of these plantations in recent decades reflects major competitive advantages of eucalypts relative to other tree species in terms of productivity, tolerance to biotic and abiotic stresses, wood quality for a wide variety of uses and ability to be managed in coppice. However, the requirements in water and nutrients of eucalypt trees are high to reach high biomass productions and the environmental impact of the silviculture is still a matter of debate. In a context of global changes with more frequent drought events, temperature rise and rapid expansion of pests and diseases, the sustainability of eucalypt plantations is of concern in many regions. Interdisciplinary research is urgently needed to improve the adaptation of eucalypt plantations to global changes. Cirad and I-Site MUSE organize an international conference under the auspices of IUFRO (Division 2.08.03 Improvement and culture of eucalypts and Division 1.02.01 Ecology and silviculture of plantation forests in the tropics) to present recent advances likely to improve the management of eucalypt plantations in tropical, sub-tropical and Mediterranean regions. The objectives of the conference are: 1. to strengthen a community of researchers and forest managers concerned by the sustainability of forest plantations. 2. to present recent technical and scientific innovations making it possible to improve the management and the ecosystem services of eucalypt plantations. 3. to explore new strategies in tree breeding and silviculture for better adaptation of eucalypt plantations to the major abiotic and biotic stresses that are expected to increase with global changes. 4. to discuss research priorities to improve the sustainability of eucalypt plantations, fueling a growing demand for wood while maintaining environmental and social services in rural areas The conference is organized in plenary sessions to promote interdisciplinary discussions between forest managers and researchers specialized in tree breeding, silviculture, forest pathology, wood science as well as environmental and social sciences. This book includes the abstracts of 13 keynotes, 55 oral presentations, 18 lighting talks and 132 posters presented during the conference. Jean-Paul Laclau Cirad, UMR Eco&Sols Chair Eucalyptus 2018 Title : Eucalyptus 2018 : Managing Eucalyptus plantations under global changes Autors : IUFRO 2.08.03 Montpellier Co-Editors : Jean-Paul Laclau, Eric Mignard, Jean-Marc Bouvet, Louis Mareschal Editor Institution : Cirad Date : 2018-08-31 ISBN : 978-2-87614-743-0 EAN : 9782876147430 Key Notes 2 Resilience of primary metabolism of eucalypts to variable water and nutrients Mark Adams ∗y 1, Heinz Rennenberg 2, Jorg Kruse 2 1 Swinburne University of Technology [Melbourne] (SUT) { John Street, Hawthorn, Victoria, Australia 2 University of Freiburg [Freiburg] (Uni Freiburg) { Friedrichstr. 39 79098 Freiburg, Germany The genus Eucalyptus and closely related genera, have evolved in a wide range of environ- ments, but especially under well illuminated, dry and warm-hot conditions, on poor soils. Over many years, we have explored responses of the primary metabolism of eucalypts to changing light, nitrogen, water and temperature regimes. Ecological growth strategies are reflected in traits such as the photosynthetic and respiratory capacity of leaves, which determine much of plant carbon balance. As an example, contrasting light environments and nitrogen supply have different effects on Flooded Gum (Eucalyptus grandis) and Mountain Ash (E. regnans), growing under warm-temperate conditions. E. grandis produced three-fold more biomass than E. reg- nans, and benefitted more from enhanced supplies of nitrogen, in particular under semi-shade conditions. Acclimation of leaf mass per area to growth irradiance was more plastic in E. gran- dis, and scaled positively with area-based photosynthesis. In E. regnans, growth under high irradiance and nitrogen availability caused significant accumulation of foliar N, which was not matched by mostly small increases in photosynthetic capacity. Foliar nitrogen was used more ef- fectively for the production of new foliage in E. grandis, owing to better coordination with foliar capacity and flux mode of mitochondrial oxygen reduction. Just a few physiological/anatomical variables are needed to explain these results, including: foliar density of mitochondria, average nitrogen concentration per mitochondrion, and relative demand for energy versus anabolic inter- mediates. Demand for anabolic intermediates is one of the major differences among Eucalyptus spp and new approaches to physiological modeling are needed to capture `sink-driven' rates of carbon fixation, and better predict growth. Keywords: Eucalypt ∗Speaker yCorresponding author: [email protected] 3 Abiotic stresses: where ecophysiology meets management Daniel Binkley ∗ 1 1 Northern Arizona University [Flagstaff] (NAU) { Flagstaff Arizona 86011, United States The production of Eucalyptus forests is usually limited by abiotic factors in the environment. Nutrient supply is one of the most severe potential limitations on production, but intensive fer- tilization often minimizes this limitation. Ecophysiological stress related to temperature and moisture also limit production in most plantations. Across the state of Bahia in Brazil, opera- tional plantations in the 1990s mid-rotation wood production increased from about 12 Mg ha-1 yr-1 with 900 mm yr-1 of rain to 25 Mg ha-1 yr-1 with 1500 mm yr-1 of rain. The TECHS project found a similar trend across tropical and subtropical regions of Brazil. An increase in precipitation of 100 mm yr-1 was associated with an increase of 1.5 to 1.8 Mg ha-1 yr-1 of wood production. However, drier sites have not only lower supplies of water but often higher temperatures and lower atmospheric humidity. Increases of 1 oC in mean annual temperature in the TECHS project were associated with declines of 2.9 Mg ha-1 yr-1 in wood production. When the effect of temperature was also included, the response to increasing rainfall was only 0.4 Mg ha-1 yr-1 for a 100 mm yr-1 increase in rainfall. On-site manipulations of water supply, through irrigation or rainfall exclusion, are needed to separate the effects of rainfall from tem- perature. Insights about the exact ecophysiological limitations on production may have value in both silviculture and genetic selection silviculture. If production is limited by water sup- ply, choices about tree spacing may be fundamental for balancing stand-level growth and tree mortality. The sensitivity of leaves to low humidity might limit growth even on soils with high water holding capacity, and genetic selection might offer site-specific opportunities to balance site water supply and tree responses to dryness of the air. Keywords: Water, temperature, humidity, production ∗Speaker 4 What's beyond wood fibre for eucalypt industrial plantations. Nuno Borralho ∗y 1, Alexandre Gaspar 1, Carlos Pascoal Neto 1 1 Forest and Paper Research Institute (RAIZ) { Quinta de S~aoFrancisco, 3801-501 Eixo, Aveiro, Portugal The expansion of eucalypt plantations around the world, which by now would have reached 25 million hectares, has been mostly driven by industrial demand from pulp, paper and card- board industries. Developments in genetics and silviculture have therefore been mostly targeting more productive pulpwood plantations with fibre characteristics suiting a single end product. The societal move to a fuller and more efficient, cross-sectorial utilization of the various biomass components, beyond the strict linear chain from pulpwood to paper, in what has been referred to as The Bio-economy, challenges the use and design of eucalypt plantations as they are perceived and managed today. They will be expected to provide simultaneous production of a range of industrial goods (paper products, chemicals, energy and plantation timber) as well as other more elusive but equally relevant environmental services. The putative declining of printing and writing paper markets, although not threatening the global pulpwood business model in the short run, will certainly change the way industrial plan- tations will be managed and certified hence raising new issues for forest scientists and managers to address. In this paper we will review the implications of these recent developments on the present and future research agendas as related to eucalyptus plantations, with special emphasis on the im- pact they will have and the opportunities they will create in areas such as forest genetics, biotechnology and forest management. Keywords: Pulp and Paper, Energy, Biorefinaries ∗Speaker yCorresponding author: [email protected] 5 The production ecology of mixtures: From pattern to process to application David Forrester ∗y 1 1 1Swiss Federal Institute for Forest, Snow and Landscape Research WSL (WSL) { Zuercherstr. 111, 8903 Birmensdorf, Switzerland Mixed-species