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Habitat loss and fragmentation are key processes causing biodiversity loss in human‐modified landscapes. Knowledge of these processes has largely been derived from measuring biodiversity at the scale of 'within‐habitat' fragments with the surrounding landscape considered as matrix. Yet, the loss of variation in species assemblages 'among' habitat fragments (landscape‐scale) may be as important a driver of biodiversity loss as the loss of diversity 'within' habitat fragments (local‐scale). We tested the hypothesis that heterogeneity in vegetation cover is important for maintaining alpha and beta diversity in human‐modified landscapes. We surveyed bird assemblages in eighty 300‐m‐long transects nested within twenty 1‐km2 vegetation 'mosaics', with mosaics assigned to four categories defined by the cover extent and configuration of native eucalypt forest and exotic pine plantation. We examined bird assemblages at two spatial scales: 1) within and among transects, and 2) within and among mosaics. Alpha diversity was the mean species diversity within‐transects or within‐mosaics and beta diversity quantified the effective number of compositionally distinct transects or mosaics. We found that within‐transect alpha diversity was highest in vegetation mosaics defined by continuous eucalypt forest, lowest in mosaics of continuous pine plantation, and at intermediate levels in mosaics containing eucalypt patches in a pine matrix. We found that eucalypt mosaics had lower beta diversity than other mosaic types when ignoring relative abundances, but had similar or higher beta diversity when weighting with species abundances. Mosaics containing both pine and eucalypt forest differed in their bird compositional variation among transects, despite sharing a similar suite of species. This configuration effect at the mosaic scale reflected differences in vegetation composition among transects. Maintaining heterogeneity in vegetation cover could help to maintain variation among bird assemblages across landscapes, thus partially offsetting local‐scale diversity losses due to fragmentation. Critical to this is the retention of remnant native vegetation. [ABSTRACT FROM AUTHOR]

Abstract The WRKY transcription factors, a large family of proteins in plants, are involved in multiple developmental and biological processes including response to phytohormones and abiotic stress. However, little information is available regarding the WRKY family in Eucalyptus , which has been the most widely planted hardwood trees in tropical and subtropical areas. In this study, a total of 79 WRKY genes (named as EgrWRKY1 - 79) were identified from the Eucalyptus grandis genome and classified into three main groups according to the phylogenetic analysis, which was further supported by their gene structure and conserved motifs. Of which, 28 EgrWRKYs were involved in tandem duplication but none for segmental duplication, indicating that tandem duplication was the main cause for the expansion of WRKY gene family in E. grandis. Subsequently, expression profiles of EgrWRKY genes in eight different tissues and in response to treatments of three hormones (SA, JA, and BR) and two abiotic stresses (salt and cold) were analyzed. The results revealed that the EgrWRKY genes had differential expression in their transcript abundance and they were differentially expressed in response to plant hormones and salt and cold stresses, suggesting their contributions to plant developmental processes as well as abiotic stresses with the involvement of hormone signaling transduction. Taken together, these findings will increase our understanding of EgrWRKY gene family involved in abiotic stresses and hormone signaling transduction, and also will provide some stress-responsive candidate EgrWRKY genes for further characterization of their functions in Eucalyptus. Highlights • 79 WRKY genes were identified in Eucalyptus grandis. • Their phylogenetic tree, gene structure, and conserved motifs were studied. • Expression pattern of EgrWRKY genes in eight different tissues • Expression of EgrWRKYs in response to three hormones of SA, JA, and BR • Expression of EgrWRKYs in response to salt and cold [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We used ALS, WorldView-2 and SAR imagery to upscale tree numbers. • ALS derived tree numbers were used for training a random forest regressor. • We upscaled tree numbers with R2 of 0.61 and normalized RMSE of 62%. • The ALS and WorldView-2 predictors were the best for estimating tree numbers. • The SAR predictors alone were unable to estimate tree numbers reliably. Abstract Detailed information on the number and density of trees is important for conservation and sustainable use of forest resources. In this respect, remote sensing technology is a reliable tool for deriving timely and fine-scale information on forest inventory attributes. However, to better predict and understand the functioning of the forest, fine-scale measures of tree number and density must be extrapolated to the forest plot or stand levels through upscaling. In this study, we compared and combined three sources of remotely sensed data, including low point density airborne laser scans (ALS), synthetic aperture radar (SAR) and very-high resolution WorldView-2 imagery to upscale the total number of trees to the plot level in a structurally complex eucalypt forest using random forest regression. We used information on number of trees previously derived from high point density ALS as training data for a random forest regressor and field inventory data for validation. Overall, our modelled estimates resulted in significant fits (p < 0.05) with goodness-of-fit (R2) of 0.61, but systematically underestimated tree numbers. The ALS predictor variables (e.g. canopy cover and height) were the best for estimating tree numbers (R2 = 0.48, nRMSE = 61%), as compared to WorldView-2 and SAR predictor variables (R2 < 0.35). Overall, the combined use of WorldView-2, ALS and SAR predictors for estimating tree numbers showed substantial improvement in R2 of up to 0.13 as compared to their individual use. Our findings demonstrate the potential of using low point density ALS, SAR and WorldView-2 imagery to upscale high point density ALS derived tree numbers at the plot level in a structurally complex eucalypt forest. [ABSTRACT FROM AUTHOR]

Abstract N-Ethyl perfluorooctane sulfonamide (EtFOSA) is a perfluorooctane sulfonate (PFOS) precursor and the active ingredient in sulfluramid, a pesticide which is used extensively in Brazil for management of leaf cutting ants. Here we investigate the occurrence of EtFOSA, PFOS, and other per- and polyfluoroalkyl substances (PFASs) in soil, eucalyptus leaves, water (ground, riverine, and coastal (estuarine/marine)) and coastal sediment from an agricultural region of Bahia State, Brazil. This area contains a larger number of eucalyptus plantations where sulfluramid is suspected to be applied. Soil, leaves, and coastal water (marine/estuarine) contained ∑PFAS concentrations of up to 5400 pg g−1, 979 pg g−1, and 1020 pg L−1, respectively, with PFAS profiles generally dominated by PFOS and perfluorooctane sulfonamide (FOSA). Coastal sediment contained ∑PFAS concentrations of up to 198 pg g−1, with PFOS, FOSA, and perfluorooctanoic acid (PFOA) being the most frequently observed PFASs. These substances are all potential EtFOSA transformation products, pointing to sulfluramid as a possible source. In riverine water, ∑PFAS concentrations of up to 8930 pg L−1 were observed. PFOS and PFOA were detected in all river water samples. Groundwater also exhibited PFAS contamination (5730 pg L−1 ∑PFASs), likely from sulfluramid use. The observation of other PFASs (e.g. perfluorobutanoic acid) in freshwater suggests that other PFAS sources (in addition to sulfluramid) may be important in this region. Overall, these data support the hypothesis that sulfluramid use contributes to the occurrence of PFASs in the Brazilian environment. Graphical abstract Image 1 Highlights • EtFOSA transformation products (e.g. PFOS, FOSA) were observed in soil, leaves, and marine waters from Brazil. • The remoteness of sampling area points to Sulfluramid use in Brazilian agriculture as a source of PFASs in this environment. • Coastal marine sediment appears to be a major sink for PFASs. [ABSTRACT FROM AUTHOR]

Abstract The Iberian Peninsula (Iberia) is a key region for preserving many endangered habitats and species. High biodiversity areas, such as Natura 2000 sites and High Nature Value farmlands, are widespread in Iberia. However, the massive, uncontrolled proliferation of exotic Eucalyptus globulus plantations in some regions may jeopardise conservation goals. It is thus important to assess the potential conflicts of E. globulus plantations with high biodiversity areas, both in current and future times. We applied species distribution models to project the current and future potential ranges of E. globulus plantations in Iberia, considering two representative concentration (of greenhouse gas) pathways (RCP): RCP2.6 and RCP8.5. Projections include a range of environmental suitability for E. globulus plantations. These projections were assessed in relation to the distribution of the Natura 2000 sites and High Nature Value farmlands. Conflicts were rated based on the combination between the level of suitability for plantations and the level of biodiversity importance in a grid of cells covering Iberia. Eucalyptus globulus plantations are currently widespread inside the Natura 2000 network of the Iberian Peninsula. In a few Natura 2000 sites, E. globulus cover increased after their designation as a protected area. Overall, plantations expanded greatly around Natura 2000 sites. The species distribution model showed that the current potential range of E. globulus plantations extends over 18% of Iberia, mostly along the Atlantic shore, being mainly determined by the minimum temperature of the coldest month. The future projections show a northward contraction of the suitable range, especially under the RCP8.5 (warmer scenario). However, the suitability for E. globulus plantations will improve in most of the receding range, leading to an aggravation of the potential conflicts with those high biodiversity areas. This study helps identify priority areas to prevent further impacts of E. globulus plantations on Iberian biodiversity. [ABSTRACT FROM AUTHOR]

Abstract: Habitat fragmentation results in landscape configuration, which affects the species that inhabit it. As a consequence, natural habitat is replaced by different anthropogenic plantation types (e.g. pasture, agriculture, forestry plantations and urban areas). Anthropogenic plantations are important for biodiversity maintenance because some species or functional groups can use it as a complementary habitat. However, depending on plantation permeability, it can act as a barrier to the movement of organisms between habitat patches, such as forest fragments, reducing functional connectivity for many species. Anthropogenic plantations are becoming the most common land use and cover type in the Anthropocene and biodiversity conservation in fragmented landscapes requires information on how different plantation types affect the capacity of the species to move through the landscape. In this study, we evaluated the influence of the type and structure of plantations on the movement of two forest‐dependent understory bird species – plain antvireo (Dysithamnus mentalis) and flavescent warbler (Myiothlyps flaveola) – within a highly fragmented landscape of Atlantic Forest hotspot. Knowing that forestry plantation is assumed to be more permeable to dependent forest bird species than open ones, we selected six study areas containing a forest fragment and surrounding plantation: three with sugarcane plantation and three with Eucalyptus sp. plantation. We used playback calls to stimulate the birds to leave forest fragments and traverse the plantations. Control trials were also carried out inside the forest fragments to compare the distances crossed. We observed that individuals moved longer distances inside forest than between plantation types, which demonstrate that plantations do constrict the movements of both species. The two plantation types equally impeded the movements of the species, suggesting the opposite of the general assumption that forestry plantations are more permeable. Our results indicate that, for generalist species, plantation type does not matter, but its presence negatively impacts movement of these bird species. We highlight that plantations have negative influences on the movements of common bird species, and discuss why this is important when setting conservation priorities. [ABSTRACT FROM AUTHOR]

Abstract: Compared to tree responses to elevated (e)CO2, little attention has been paid to understorey plant community responses in forest ecosystem studies, despite their critical role in nutrient cycling and the regeneration of overstorey species. Here, we present data on understorey responses from a 3‐year Free‐Air CO2 Enrichment experiment in a native, phosphorus‐limited Eucalyptus woodland in Australia (EucFACE). We conducted repeat surveys of the understorey plant community from 2012 to 2016, recording cover at the species level. Three years of eCO2 significantly decreased the diversity (Shannon‐Weaver; −30%) and species richness (−15%; c. −1 species per 4 m2 plot) of graminoid species, and the cover of C4 graminoids in both dominant (−38%) and subordinate (−48%) groups, relative to ambient conditions, leading to a significantly lower graminoid C4:C3 ratio (−59%) in the understorey plant community. The ratio of C4:C3 graminoids was negatively associated with soil nitrogen (N) availability suggesting that previously reported eCO2‐associated increases in N availability may contribute to (or be a consequence of) shifts in the composition of the graminoid community at the study site. There was, however, no effect of eCO2 on the diversity of forb species, which represented the most species‐rich functional group but only c. 1% of the understorey biomass. Synthesis. Our results suggest that eCO2 influences competition between C4 and C3 graminoid species both directly and indirectly via increasing N availability. The shift towards lower C4:C3 ratios and enhanced dominance by C3 species with their generally higher tissue N concentrations could further change soil nutrient availability and potentially accelerate community succession. Thus, eCO2 has altered the diversity and composition of the understorey plant community in this woodland, with the potential for cascading consequences for trophic interactions and ecosystem function. [ABSTRACT FROM AUTHOR]

* Background and Aims Evolutionary change in developmental trajectories (heterochrony) is a major mechanism of adaptation in plants and animals. However, there are few detailed studies of the variation in the timing of developmental events among wild populations. We here aimed to identify the climatic drivers and measure selection shaping a genetic-based developmental cline among populations of an endemic tree species complex on the island of Tasmania. * Methods Seed lots from 38 native provenances encompassing the clinal transition from the heteroblastic Eucalyptus tenuiramis to the homoblastic Eucalyptus risdonii were grown in a common-garden field trial in southern Tasmania for 20 years. We used 27 climatic variables to model the provenance variation in vegetative juvenility as assessed at age 5 years. A phenotypic selection analysis was used to measure the fitness consequences of variation in vegetative juvenility based on its impact on the survival and reproductive capacity of survivors at age 20 years. * Key Results Significant provenance divergence in vegetative juvenility was shown to be associated with home-site aridity, with the retention of juvenile foliage increasing with increasing aridity. Our results indicated that climate change may lead to different directions of selection across the geographic range of the complex, and in our mesic field site demonstrated that total directional selection within phenotypically variable provenances was in favour of reduced vegetative juvenility. * Conclusions We provide evidence that heteroblasty is adaptive and argue that, in assessing the impacts of rapid global change, developmental plasticity and heterochrony are underappreciated processes which can contribute to populations of long-lived organisms, such as trees, persisting and ultimately adapting to environmental change. [ABSTRACT FROM AUTHOR]

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The advantages of green synthesized iron nanoparticles by plant extracts include simplicity, high efficiency and sustainability. However, there are limitations in our understanding of the formation of Fe NPs. In this report, the synthesized iron nanoparticles by eucalyptus leaf extract (Fe NPs) showed that Cr(VI) removal efficiency reached approximately 100% at volume ratio of leaf extract and iron(III) solution of 2:1 and pH 4. In addition, the morphology, surface and compositions of Fe NPs were characterized by various techniques. The diameter distribution of 95 ± 5 nm with a capping layer was observed, containing polyphenols and aliphatic acids confirmed by FTIR and XRD. XPS indicated that Fe NPs contained iron oxides, as well as a layer covering on Fe NPs created by biomolecules from eucalyptus leaf extract. Furthermore, the biomolecules identified by GC-MS indicated that alcohol phenols and alkylaldehyde acted as reducing agents, while alcohol acids, alkanols, phytols, acetate and aromatic ketones acted as capping agents. It can be concluded that aldehydes, phenols and alcoholic compounds played dominant roles during the synthesis of Fe NPs. Finally, the mechanism for the formation of Fe NPs was proposed, including both that of Fe NPs and capped Fe NPs. [ABSTRACT FROM AUTHOR]

El Inventario Forestal Nacional (IFN) es una valiosa fuente de información sobre los recursos forestales de nuestro país. Sin embargo, su periodicidad de diez años no es suficiente para caracterizar adecuadamente ciertas especies, como son las de crecimiento rápido. El presente estudio aporta una metodología complementaria para actualizar la información sobre estas especies, en periodos de tiempo más cortos que el ciclo de realización del IFN. Además se ha generado dicha información con las herramientas y software más económicos. En este caso, el ámbito del estudio son las masas de eucalipto de la provincia de Lugo. [ABSTRACT FROM AUTHOR]

Laboratory studies have shown that priming effects, caused by inputs of carbon into the rhizosphere, can change the rate of soil organic matter (SOM) decomposition and could have significant impacts on soil carbon cycling. However, there have been few studies in field conditions because of experimental constraints but field data are needed to improve models that forecast the effects of climate change on SOM decomposition rates and the impact of these changing rates on atmospheric CO 2 concentration. In 2009 a fire at a Eucalyptus forest site in Australia killed all standing vegetation. Trenched plots were installed in 2010, approximately 12 months after the fire, and were maintained plant-free for the subsequent year. In 2011, after forest re-growth outside the trenched plots, we compared SOM decomposition rates in the presence of plants (rooted plots) and in the absence of plants (trenched plots) using a natural abundance stable carbon isotope technique with minimal disturbance of the soil. We then compared our results to those obtained in another study conducted at the same time and the same plots using laboratory incubations of sieved soil samples. There was no difference in SOM decomposition rates between the trenched and the rooted plots estimated using our non-disruptive technique. In contrast, laboratory incubations of sieved soils highlighted a two-fold increase in SOM decomposition rates in the rooted plots compared with rates from the trenched plots. Our results suggest that rhizosphere priming may not actively influence soil carbon turnover in the undisturbed soil environment and question conclusions from laboratory incubation studies. We attribute the different findings from laboratory and field studies to the physical disturbance of the soil involved in laboratory incubations causing the release of previously protected substrates, making them available for decomposition. [ABSTRACT FROM AUTHOR]

A mixed-species plantation of Acacia mangium (acacia) and Eucalyptus urophilla x grandis (eucalypt) hybrid was established on the Arenosols of the coastal Congolese plains to improve soil fertility and sustain forest plantation productivity. At one year into the second rotation, some of the acacia started to exhibit yellowing and drying of leaves, resulting in the death of the whole tree. One-third of the pure acacias (100A) and the mixed, 50 % acacia and 50 % eucalypt (50A50E) hybrid, exhibited these characteristics five months later. To limit the damage, the acacias were pruned up to 1.30 meters. The acacias were threatened by a dry season that extended two months longer than during the previous year, probably triggered by sandy textured soils and poor soil fertility (nitrogen < 0.07 % in the 0.05 meters). Soil moisture to a depth of 0.15 meters was higher under eucalypt compared to acacia. It appears that the acacia root structure may have been less tolerant to drought conditions compared with the eucalypts, leading to damage of acacias, which was exacerbated by the acacia's young age, poor soil fertility and sandy soil texture. One year after pruning, acacias in both 100A and 50A50E presented a healthier tree structure. Furthermore, no negative impact on aboveground biomass -i.e., wood, bark, leaves and branch- has been recorded at 12 and 24 months. [ABSTRACT FROM AUTHOR]

This study examines the potential of airborne laser scanning (ALS) to predict diameter distributions in an even-aged plantation of Eucalyptus urograndis in Brazil. The single-species plantation conditions allow different modelling alternatives to be compared without the presence of minor tree species or an understory layer affecting the results. Three modelling alternatives based on the two-parametric Weibull function form; parameter prediction, parameter recovery and distribution matching were tested with a k-nearest neighbour prediction (k-nn) method. We also evaluated a parameter prediction alternative, in which the Weibull distribution was predicted using field attributes. The results showed that ALS information can predict diameter distributions with an error margin of slightly more than 10 per cent of the RMSE of the mean of the third power of diameter, and with error index values between 50 and 60. The degree of accuracy was only slightly improved when the Weibull distribution was predicted using field attributes. According to the accuracy metrics, the differences between modelling alternatives were minor but parameter recovery and k-nn seem to be the most favourable ALS-based prediction methods. To conclude, the results showed a strong relationship between ALS information and diameter distributions in a tropical single-species plantation and we discuss how these results could be applied in other types of forests. [ABSTRACT FROM AUTHOR]

Diseases caused by species of Calonectria (Ca.) represent a serious threat to the growth and sustainability of Eucalyptus plantations in China. Symptoms caused by these fungi mainly include leaf blight on trees in plantations and rotting of stems and leaves in nurseries. Extensive surveys have recently been conducted where Calonectria species were collected in Eucalyptus plantations and nurseries in the FuJian, GuangDong, GuangXi, and YunNan Provinces of South China. Additional isolates were baited from soil samples in the Hong Kong Region. The aim of this study was to identify the 115 Calonectria isolates obtained using comparisons of DNA sequence data for the β-tubulin (tub2), calmodulin (cmdA), histone H3 (his3) and partial translation elongation factor-1α (tef1) gene regions as well as their morphological features. Seven known species were identified, including Calonectria arbusta, Ca. asiatica, Ca. chinensis, Ca. eucalypti, Ca. hongkongensis, Ca. mossambicensis and Ca. pentaseptata. In addition, six novel taxa were collected and are described here as Ca. aciculata, Ca. honghensis, Ca. lantauensis, Ca. pseudoturangicola, Ca. pseudoyunnanensis, and Ca. yunnanensis spp. nov. Overall, the results reflect a high diversity of Calonectria species in China. [ABSTRACT FROM AUTHOR]

Intensively managed plantations account for 1.5% of the world’s forests, but they meet one-third of the demand for wood products. Eucalyptus plantations are among the most productive, with rates of growth depending heavily on genetics, silviculture, and climate. The TECHS Project examines productivity at 36 locations across a 3500 km gradient from Brazil to Uruguay, testing the interacting influences of genetics, temperature and precipitation on stemwood production. Across all sites and genotypes, stemwood production in the middle of the 6-year rotation (the peak period of growth) averaged 22 Mg ha −1 yr −1 . Production varied by fivefold across sites, and by about 2-fold among genotypes within each site. The best clones at each location grew 1.5–4 Mg ha −1 yr −1 more than the average for all clones, underscoring the importance of matching genotypes to local site conditions. Contrary to patterns for natural forests across geographic gradients, Eucalyptus production declined with increasing temperature, dropping by 2.5 Mg ha −1 yr −1 for a 1 °C temperature increase. The temperature effect was likely driven in part by the geographic covariance of temperature and rainfall, as rainfall tended to decline by 78 mm yr −1 for each 1 °C increase in temperature. Stemwood production increased an average of 1.5 Mg ha −1 yr −1 for each 100 mm yr −1 increase in precipitation, but when the covariation of temperature and precipitation were included the apparent influence of precipitation declined to 0.4 Mg ha −1 yr −1 for each 100 mm yr −1 increase in precipitation. Future results will determine if within-site reductions in ambient rainfall have the same apparent influences as the rainfall pattern across the geographic gradient, as well as quantifying the importance of insects and pests in affecting growth. The supply of wood from intensively managed plantations will be strongly influenced by both temperature and precipitation at plantation locations, and with changing climates. [ABSTRACT FROM AUTHOR]

UNESCO's World Heritage Convention provides for the protection of natural and cultural heritage deemed to be of Outstanding Universal Value. The 1031 sites inscribed on World Heritage List are a source of prestige for the countries where they occur. However, conflicts between protection of Outstanding Universal Value and resource extraction can arise within large-scale natural landscapes. The tall-eucalypt forests of the Australian island of Tasmania have been at the heart of such a conflict for over 30 years. The aim of this paper is to analyse how the processes of the Convention respond to contrasting approaches by a State Party. The paper traces the history of the dispute over Tasmania's tall-eucalypt forests through the Convention's processes of evaluation, inscription and boundary modification. In particular, it considers the processes and outcomes pertaining to two diametrically opposed proposals for minor modification to the boundaries of the Tasmanian Wilderness made by consecutive Australian governments in 2013 and 2014: the first was for the purpose of protecting the forests, and the second for opening them to logging in order to fulfil a domestic election promise. In each case, criteria weighted in favour of long-term heritage protection played a critical role. The application of these criteria, combined with strong domestic concern and the ability of UNESCO's World Heritage Committee to prioritize heritage protection, has resulted in the protection of these forests and the enhancement of the ecological resilience of the Tasmanian Wilderness World Heritage Area. The paper concludes that the power of an international treaty can transcend the vicissitudes of domestic politics and provide enduring protection of Outstanding Universal Value, particularly when backed by strong domestic scrutiny and community support. [ABSTRACT FROM AUTHOR]

Forest certification is a practice that has been consolidated worldwide in recent years as a result of certification often being associated with sustainability. However, there is not much research available on the perception of stakeholders and experts of that association. This study evaluates how key stakeholders relate certification to sustainability, and its implications for forest management. A survey was implemented in the eucalyptus plantations of Galicia, northwestern Spain, to assess how forest managers; advisors; environmental organizations; researchers; and members from the FSC (Forest Stewardship Council), PEFC (the Program for Endorsement of Forest Certification), and forest companies and associations, perceive this relationship. The opinions indicate that it should not be assumed that certified plantations are necessarily perceived as the most sustainable ones, that there is always a direct relationship between certification, nor that forest owners and managers certify their woodlands in order to guarantee sustainability. The results also showed that perceptions of certification and sustainability were not influenced by the opinions of different groups of stakeholders. [ABSTRACT FROM AUTHOR]

The Atlantic forest biome in Brazil possesses many suitable tree species for cultivation and restoration purposes. This biome was the most rapidly and extensively exploited forest type in Brazil and it displays areas ill-suited for eucalyptus cultivation. Since tropical tree species usually do not form growth rings and long-term growth data are still not available in Brazil, this study addressed a new approach to diameter growth rate estimation. The approach was developed in order to alleviate the shortage of species-specific growth information for the Atlantic forest biome. The two reasons for developing the approach were: (1) the possibility of increased ecological and economic diversification of plantation forests beyond eucalyptus, and (2) the potential to identify suitable tree species for restoration programs in the biome. Either reason requires growth models with sound biological properties. The data used in this study came from 20 native forest fragments and included six tropical tree species. Forest inventory to assess forest growth was first conducted in 2003, while the re-measurement was conducted in 2008. A non-linear exponential model, containing an asymptote parameter as a function of stand density, was fit to estimate tree species diameter growth rate for each of the six tree species in the study. Additionally, based on the exponential model, a formulation of the time required for each tree species to reach a given diameter was developed. The fitted models exhibited high variability among the six tree species, but they performed well with respect to tree growth behavior. Since the model accounted for stand density, it was possible to predict how different stand densities would affect each tree species growth over time. Finally, the tree species Triplaris gardneriana Weddell, Inga vera Willd. and Xylopia brasiliensis Spreng are recommended as potentially fast-growing tree species in the Atlantic forest biome. These tree species exhibited good growth rates regardless the stand density simulated (1600/ha, 2000/ha, and 2400/ha) to reach a dbh of 10 cm ( Xylopia brasiliensis Spreng - 16 years, 17 years, and 18 years; Triplaris gardneriana Weddell - 15 years, 17 years, and 21 years; Inga vera Willd. - 25 years, 25.5 years, and 26 years) and showed promising potential for both restoration and production programs. The developed approach reveals a unique diameter growth rate prediction method. [ABSTRACT FROM AUTHOR]

Most eucalypt plantations are managed in short rotations (6–8 years) and are established in regions with water and nutritional stresses of varying degrees. The mean annual increment in these regions ranges from 20 to 45 m3ha−1y−1depending on the level of environmental stress. Improving natural resource use efficiency by breeding and matching genotypes to sites and using appropriate site management practices is a key challenge to sustain or increase productivity. Climate change is emerging as a driving force behind many of the current issues facing natural resources, and is likely to intensify the water constraint. The Intergovernmental Panel on Climate Change has predicted significant increases in surface air temperatures and decreases in rainfall (with more erratic rainfall patterns) over the tropics and subtropics, affecting drier regions in particular. To be truly sustainable, forest management practices must be environmentally friendly, prevent or reduce land degradation, improve biodiversity and increase resilience to climate variation and change. The main efforts should address the problems of water scarcity, low soil fertility and reduced biodiversity. Forest growers should take into account the inherent risks of different forest management systems on the regional water availability and consider reducing forest productivity in order to maintain both ecological and social equilibrium. The design and implementation of management techniques should be adapted to the specific production and protection objectives, which depend on the regional and local edaphoclimatic circumstances, water resources management, protection against soil erosion, diseases, pests, bushfires, strong winds and alien species. This paper addresses the basic requirements for integrating genetic and silvicultural strategies to minimise the water constraints in eucalypt plantations and surrounding water and native vegetation resources. We show several examples of effective forest management actions on the scale of forest stand and watershed in use in Brazil. [ABSTRACT FROM PUBLISHER]

The potential energy balance of the sawing logs for Eucalyptus lumber production was determined. Eucalyptus grandis logs (n = 10) were sawn with a band saw, and the planks were re-sawed with a circular saw. The sawing yield was calculated with the volumes of logs, lumbers, and wastes. The consumption of electric energy was measured using a multifunctional meter. The energy stored in the wood was determined by the lower calorific value of wood; the superior calorific value was calculated and converted into the respective active energy (kWh) value. The potential energy balance was calculated using the values of the consumed electricity in the saws and that of the energy stored in the waste. Another energy balance was calculated by considering the energy stored in the timber. The potential energy balance for sawing 1 m3 of log was equal to 1,206 kWh, considering only the energy stored in the waste. When added to energy stored in the timber, the energy balance was 2,671 kWh. The positive results of energy balances demonstrate the potential of energetic self-sufficiency of timber production. [ABSTRACT FROM AUTHOR]

While the eddy covariance technique has become an important technique for estimating long-term ecosystem carbon balance, under certain conditions the measured turbulent flux of CO2 at a given height above an ecosystem does not represent the true surface flux. Profile systems have been deployed to measure periodic storage of CO2 below the measurement height, but have not been widely adopted. This is most likely due to the additional expense and complexity and possibly also the perception, given that net storage over intervals exceeding 24 h is generally negligible, that these measurements are not particularly important. In this study, we used a 3-year record of net ecosystem exchange of CO2 and simultaneous measurements of CO2 storage to ascertain the relative contributions of turbulent CO2 flux, storage, and advection (calculated as a residual quantity) to the nocturnal CO2 balance and to quantify the effect of neglecting storage. The conditions at the site are in relative terms highly favourable for eddy covariance measurements, yet we found a substantial contribution (~40 %) of advection to nocturnal turbulent flux underestimation. The most likely mechanism for advection is cooling-induced drainage flows, the effects of which were observed in the storage measurements. The remaining ~60% of flux underestimation was due to storage of CO2.We also showed that substantial underestimation of carbon uptake (approximately 80gCm-2 a-1, or 25% of annual carbon uptake) arose when standard methods (u* filtering) of nocturnal flux correction were implemented in the absence of storage estimates. These biases were reduced to approximately 40-45 gCm-2 a-1 when the filter was applied over the entire diel period, but they were nonetheless large relative to quantifiable uncertainties in the data. Neglect of storage also distorted the relationships between the CO2 exchange processes (respiration and photosynthesis) and their key controls (light and temperature respectively). We conclude that the addition of storage measurements to eddy covariance sites with all but the lowest measurement heights should be a high priority for the flux measurement community. [ABSTRACT FROM AUTHOR]

Background and aims: Comparing root functioning under contrasting rainfall regimes can help assessing the capacity of plant species to cope with more intense and frequent drought predicted under climate change context. While the awareness of the need to study the whole root system is growing, most of the studies of root functioning through rhizosphere analyses have been restricted to the topsoil. Our study aimed to assess whether the depth in the soil and the rainfall amount affect root functioning, and notably the fate of nutrients within the rhizosphere. Methods: We compared pH and nutrient availability within the rhizosphere and bulk soil along a 4-m deep soil profile in a 5-year-old eucalypt ( Eucalyptus grandis) plantation under undisturbed and reduced rainfall treatments. Results: The exchangeable K concentration and the pH of the bulk soil were not influenced by the reduced rainfall treatment. By contrast, the HO concentration in the rhizosphere was significantly greater than that of the bulk soil, only in the reduced rainfall plot. The concentrations of exchangeable K in the rhizosphere were significantly larger than those of the bulk soil in both treatments but this difference was higher in the reduced rainfall plot, notably below the depth of 2 m. Both exchangeable K and HO concentration significantly increased within the rhizosphere in the reduced rainfall treatment at soil depth down to 4 m. Conclusions: The amount of K brought to the roots by mass flow was estimated and could not explain the observed increase in exchangeable K concentration within the rhizosphere. A more likely explanation was root-induced weathering of K-bearing minerals, partly related to enhanced rhizosphere acidification. Our results demonstrate that root functioning can be considerably altered as a response to drought down to large depths. [ABSTRACT FROM AUTHOR]

Background and aims: Microbial communities and their associated enzyme activities affect the quantity and chemical quality of carbon in soil. We aimed to evaluate the biochemical mechanisms underlying how N-fixing species influences soil organic carbon chemical composition through soil microbial functional groups and enzyme activities. Methods: We examined the effects of N-fixing species mixed with Eucalyptus on soil carbon storage, and the chemical composition of an 8-year-old pure Eucalyptus urophylla plantation (PP) and a mixed E.urophylla and Acacia mangium plantation (MP). Results: The soil carbon stock and recalcitrant carbon chemical component significantly increased in surface soil in MP. The total PLFAs and bacterial PLFAs increased by 29.1% and 27.0% in cool-dry season, while in the warm-wet season, the total PLFAs and bacterial PLFAs increased by 13.1% and 27.3%, respectively. However, the fungal PLFAs decreased significantly in warm-wet season in MP. The total activity of the cellulose-degrading enzyme β-glucosidase was significantly greater with mixed N-fixing species in both dry-cool and wet-warm season. The increase in the Alk-C/O-Alk-C ratio and SOC was strongly associated with both C-acquisition activity and bacterial community. Conclusions: Our findings highlight the importance of N-fixing species in regulating both soil microbial communities and their functioning in association with soil extracellular enzyme activities, which contribute to the increased soil carbon storage and recalcitrant carbon composition in Eucalyptus plantations. [ABSTRACT FROM AUTHOR]

A research group on forest products from School of Agriculture - Sao Paulo State University. Brazil developed a portable hardness tester for wood, which is based on a displacement transducer and an embedded electronic processor for dynamic evaluation of hardness. This paper presents the results of calibration tests of the equipment, carried out on seven species of Eucalyptus. A new methodology for dynamic hardness calculation has been introduced, which relays on the reaction force of the indentation, while the measurements of indentation depth are performed under load. A moderate to strong linear correlation to Janka hardness and its variations were found. This new approach avoids the classical problems of Brinell hardness test in terms of "sinking-in" (causing diffuse edges) and elastic recovery of the indentation. [ABSTRACT FROM AUTHOR]

Sustainable forest management on a regional scale requires accurate biomass estimation. At present, technologically comprehensive forecasting estimates are generated using process-based ecological models. However, isolation of the ecological factors that cause uncertainty in model behavior is difficult. To solve this problem, this study aimed to construct a meliorization model evaluation framework to explain uncertainty in model behavior with respect to both the mechanisms and algorithms involved in ecological forecasting based on the principle of landsenses ecology. We introduce a complicated ecological driving mechanism to the process-based ecological model using analytical software and algorithms. Subsequently, as a case study, we apply the meliorization model evaluation framework to detectEucalyptusbiomass forest patches at a regional scale (196,158 ha) using the 3PG2 (Physiological Principles in Predicting Growth) model. Our results show that this technique improves the accuracy of ecological simulation for ecological forecasting and prevents new uncertainties from being produced by adding a new driving mechanism to the original model structure. This result was supported by ourEucalyptusbiomass simulation using the 3PG2 model, in which ecological factors caused 21.83% and 9.05% uncertainty in model behavior temporal and spatial forecasting, respectively. In conclusion, the systematic meliorization model evaluation framework reported here provides a new method that could be applied to research requiring comprehensive ecological forecasting. Sustainable forest management on regional scales contributes to accurate forest biomass simulation through the principle of landsenses ecology, in which mix-marching data and a meliorization model are combined. [ABSTRACT FROM PUBLISHER]

Irregular growth rings and long-lived leaves present challenges to quantify stem growth and canopy dynamics of evergreen eucalypt trees, which has impeded understanding of seasonal and inter-year biomass allocation in temperate eucalypt forests. To address this knowledge gap, we examined the sub-annual dynamics of stem and canopy growth by tree canopy class of three co-occurring species over 35 months in a temperate eucalypt forest of southeastern Australia. We used dendrometers to monitor basal area increments and daily terrestrial lidar scans to monitor integrated and height-specific canopy dynamics. Associations with concomitant weather data and stand-level carbon fluxes were used to enhance understanding of biomass allocation patterns. Comparisons of growth patterns indicated seasonal asynchronicity of stem and crown growth: the canopy expanded mainly in summer and early autumn, and the stems grew mainly in spring and autumn, but also to a lesser degree in winter. Eucalypts in the dominant crown classes grew all year, with growth allocated to crown expansion and thickening in the summer months, or to stem growth in all other months. Canopy volume was stable during the first part of the study period and subsequently increased by 20%. However, stratum-specific dynamics indicated a distinct seasonality of canopy turnover, characterised by volume gains at the top of the canopy and concurrent volume losses in the middle stratum during summer. Growth patterns, as either canopy expansion or stem increment, were not clearly associated with ecosystem-scale carbon dynamics. In addition, relationships of growth with climatic variables appeared to be associative rather than causative, indicating that allocation dynamics to root growth and nonstructural carbohydrate pools will be essential in explaining ecosystem carbon dynamics in temperate eucalypt forests. [ABSTRACT FROM AUTHOR]

Reticulate evolution by hybridization is considered a common process shaping the evolution of many plant species, however, reticulation could also be due to incomplete lineage sorting in biodiverse systems. For our study we selected a group of closely related plant taxa with contrasting yet partially overlapping geographic distributions and different population sizes, to distinguish between reticulated patterns due to hybridization and incomplete lineage sorting. We predicted that sympatric or proximal populations of different species are more likely to have gene flow than geographically distant populations of the same widespread species. Furthermore, for species with restricted distributions, and therefore, small effective population sizes, we predicted complete lineage sorting. Eastern grey box eucalypt species ( Eucalyptus supraspecies Moluccanae ) provide an ideal system to explore patterns of reticulate evolution. They form a diverse, recently evolved and phylogenetically undefined group within Eucalyptus , with overlapping morphological features and hybridization in nature. We used a multi-faceted approach, combining analyses of chloroplast and nuclear DNA, as well as seedling morphology, flowering time and ecological spatial differentiation in order to test for species delimitation and reticulate evolution in this group. The multiple layers of results were consistent and suggested a lack of monophyly at different hierarchical levels due to multidirectional gene flow among several species, challenging species delimitation. Chloroplast and nuclear haplotypes were shared among different species in geographic proximity, consistent with hybridization zones . Furthermore, species with restricted distributions appeared better resolved due to lineage sorting in the absence of hybridization. We conclude that a combination of molecular, morphological and ecological approaches is required to disentangle patterns of reticulate evolution in the box eucalypts. [ABSTRACT FROM AUTHOR]

Natural dyes are gaining interest due their expected low risk to human health and the environment and biodegradability. In addition, there are ever-growing potential new sources of natural dyes in the form of production waste products that merit consideration for coloration of materials such as textiles. Thus, an innovative approach to waste minimization through source reduction has emerged. In the present study, the potential for using colored liquid waste produced in the steam treatment of eucalyptus wood as a natural coloring matter for textile fabrics was investigated. Specifically, eucalyptus wood extract was used to dye cotton, nylon and wool in an exhaust dyeing process without the addition of the traditional mordanting agents. The resulting dyed fabrics were evaluated for color fastness and it was found that wash fastness of eucalyptus wood processing waste dyed fabrics was very good, while light fastness was typical of natural dyes in the absence of mordants. [ABSTRACT FROM AUTHOR]

Introduction: Land use/land cover change can affect the ecological processes of an area such as hydrological cycle. The change in the condition of water resources of an area could be a good indicator of changes in ecosystem function as a result of altered land use/land cover. Eucalyptus expansion in central Ethiopia is one of the recent land use/land cover changes causing controversy on its potential ecological effect. This study was designed to evaluate effects of three adjacent land uses/land covers, i.e. cultivated land, grassland and Eucalyptus woodlot on surface runoff in Meja River watershed, central Ethiopia. Methods: The rainfall amount at each study catchment was collected using the rain gauge installed to record daily rainfall amount. The three land use/land cover types in each study catchment were selected for comparison as treatments. Four replications of each land use/land cover were used forming a total of 12 runoff plots. The rainfall and runoff data were collected twice a day for 91 days. Results: The study found that land use/land cover significantly affects surface runoff generated from the plots. Higher runoff was recorded from cultivated land. There was no significant difference on runoff volume between grassland and Eucalyptus woodlot. Conclusions: This shows that expansion of Eucalyptus on grassland could not have significant impact on surface runoff generation but if planted on previously farmland could reduce surface runoff. [ABSTRACT FROM AUTHOR]

In this work, liquid nitrogen was used for the first time in the pretreatment of plant biomasses for purposes of enzymatic saccharification. After treatment (cryocrushing), the initial rates of the enzymatic hydrolysis of eucalyptus sawdust and rice hull were increased more than ten-fold. Cryocrushing did not modify significantly the contents of cellulose, hemicellulose and lignin in both eucalyptus sawdust and rice hulls. However, substantial disorganization of the lignocellulosic materials in consequence of the pretreatment could be observed by electron microscopy. Cryocrushing was highly efficient in improving the saccharification of the holocellulose component of the plant biomasses (from 4.3% to 54.1% for eucalyptus sawdust and from 3.9% to 40.6% for rice hull). It is important to emphasize that it consists in a simple operation with low requirements of water and chemicals, no corrosion, no release of products such as soluble phenolics, furfural and hydroxymethylfurfural and no waste generation. [ABSTRACT FROM AUTHOR]

Mulching is an effective post-fire soil erosion mitigation treatment. Experiments with forest residue mulch have demonstrated that it increased ground cover to 70% and reduced runoff and soil loss at small spatial scales and for short post-fire periods. However, no studies have systematically assessed the joint effects of scale, time since burning, and mulching on runoff, soil loss, and organic matter loss. The objective of this study was to evaluate the effects of scale and forest residue mulch using 0.25 m 2 micro-plots and 100 m 2 slope-scale plots in a burnt eucalypt plantation in central Portugal. We assessed the underlying processes involved in the post-fire hydrologic and erosive responses, particularly the effects of soil moisture and soil water repellency. Runoff amount in the micro-plots was more than ten-fold the runoff in the larger slope-scale plots in the first year and decreased to eight-fold in the third post-fire year. Soil losses in the micro-plots were initially about twice the values in the slope-scale plots and this ratio increased over time. The mulch greatly reduced the cumulative soil loss measured in the untreated slope-scale plots (616 g m − 2 ) by 91% during the five post-fire years. The implications are that applying forest residue mulch immediately after a wildfire can reduce soil losses at spatial scales of interest to land managers throughout the expected post-fire window of disturbance, and that mulching resulted in a substantial relative gain in soil organic matter. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the stocks of available P and S, total N, and oxidizable C at depth in an Oxisol cultivated with Eucalyptus in Brazil following different timber harvest intensities and fertilizer application over 12 years. The harvest regimes considered were (i) conventional stem-only harvest (all forest residues were maintained on the soil); (ii) whole-tree harvest (only litter was maintained on the soil--all slash, stemwood, and bark were removed); and (iii) whole-tree harvest + litter layer removal. The site was planted in 2004 considering three timber harvest intensities, some with and some without N and P fertilization. In 2012 the experiment was reinstalled, and all the treatments were reapplied in the each plot. From 2004 to 2016, nutrient accumulation and soil N, P, and S stocks were assessed in the 0-20 cm layer. Also in 2016, soil N, P, S, and oxidizable C stocks were measured to 2 m depth. For each treatment, the net balance of N, P, and S were calculated from soil stocks and harvest outputs during two forest rotations. A reduction in all nutrient stocks was observed in the 0-20 cm layer for all treatments. For N, this reduction was 20% smaller in the stem-only harvest treatment and 40% higher when no N fertilizer was applied, when compared to other treatments. Stem-only harvest treatment was observed to reduce the loss of N, P, and S due to harvest by 300, 30, and 25 kg_ha-1., respectively, when compared to the whole-tree harvest + litter layer removal treatment. [ABSTRACT FROM AUTHOR]

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Context: Edge effects due to habitat loss and fragmentation have pervasive impacts on many natural ecosystems worldwide. Objective: We aimed to explore whether, in tandem with the resource-based model of edge effects, species feeding-guild and flight-capacity can help explain species responses to an edge. Methods: We used a two-sided edge gradient that extended from 1000 m into native Eucalyptus forest to 316 m into an exotic pine plantation. We used generalised additive models to examine the continuous responses of beetle species, feeding-guild species richness and flight-capable group species richness to the edge gradient and environmental covariates. Results: Phytophagous species richness was directly related to variation in vegetation along the edge gradient. There were more flight-capable species in Eucalyptus forest and more flightless species in exotic pine plantation. Many individual species exhibited multiple-peaked edge-profiles. Conclusions: The resource based model for edge effects can be used in tandem with traits such as feeding-guild and flight-capacity to understand drivers of large scale edge responses. Some trait-groups can show generalisable responses that can be linked with drivers such as vegetation richness and habitat structure. Many trait-group responses, however, are less generalisable and not explained by easily measured habitat variables. Difficulties in linking traits with resources along the edge could be due to unmeasured variation and indirect effects. Some species' responses reached the limits of the edge gradient demonstrating the need to examine edge effects at large scales, such as kilometres. [ABSTRACT FROM AUTHOR]

Transforming plantation monocultures into sustainable, mixed-species forests that contain native species is an important goal in South China. The establishment of native species in Eucalyptus plantations is generally considered difficult, however, because of the potential allelopathic effects of Eucalyptus . In this study, a field trial with completely randomized block was conducted to determine the degree to which Eucalyptus litter and Eucalyptus roots limit the establishment of native trees in Eucalyptus plantations. Growth of seedlings of four native tree species ( Schima superba , Michelia macclurei , Cinnamomum burmannii , Cinnamomum camphora ) that were tested was inhibited by Eucalyptus roots. Seedling emergence was less sensitive than subsequent seedling growth to inhibition by Eucalyptus roots. In contrast, litter enhanced the emergence and growth of seedlings of most of the tested species ( Castanopsis chinensis , Elaeocarpus sylvestris , S. superba , Liquidambar formosana , C. burmannii , and C. camphora ), suggesting that retaining litter on the forest floor may promote the establishment and growth of native tree species in Eucalyptus plantations. We propose the following strategies for establishing native tree species in Eucalyptus plantations: (1) direct sowing of the native tree species C. chinensis , Castanea henryi , Erythrophleum fordii , and C. camphora ; (2) transplanting of E. sylvestris , S. superba , and Tsoongiodendron odorum , which had low germination rates but high seedling establishment rates; and (3) the exclusion of Eucalyptus roots via inter-row trenching to enhance the establishment of S. superba , L. formosana , C. burmannii , and C. camphora . [ABSTRACT FROM AUTHOR]

Background: The optimal allocation of resources to sexual signals and other life history traits is usually dependent on an individual's condition, while variation in the expression of sexual traits across environments depends on the combined effects of local adaptation, mean condition, and phenotypic responses to environment-specific cues that affect resource allocation. A clear contrast can often be drawn between natural habitats and novel habitats, such as forest plantations and urban areas. In some species, males seem to change their sexual signals in these novel environments, but why this occurs and how it affects signal reliability is still poorly understood. Results: The relative size of sexual traits and level of immune responses were significantly lower for male palmate newts Lissotriton helveticus caught in pine and eucalyptus plantations compared to those caught in native forests, but there was no habitat-dependent difference in body condition (n = 18 sites, 382 males). The reliability with which sexual traits signalled body condition and immune responses was the same in all three habitats. Finally, we conducted a mesocosm experiment in which males were maintained in pine, eucalypt or oak infused water for 21 days. Males in plantation-like water (pine or eucalypt) showed significantly lower immune responses but no change in body condition. This matches the pattern seen for field-caught males. Unlike field-caught males, however, there was no relationship between water type and relative sexual trait size. Conclusions: Pine and eucalyptus plantations are likely to be detrimental to male palmate newt because they are associated with reduced immune function and smaller sexual traits. This could be because ecological aspects of these novel habitats, such as high water turbidity or changes in male-male competition, drive selection for reduced investment into sexual traits. However, it is more probable that there are differences in the ease of acquisition, hence optimal allocation, of resources among habitats. Our mesocosm experiment also provides some evidence that water toxicity is a causal factor. Our findings offer insights into how plantations affect amphibian life histories, and how novel habitats might generate long-term selection for new resource allocation strategies in native species. [ABSTRACT FROM AUTHOR]

Mitigation of climate change via increased plant productivity and soil carbon (C) sequestration during land use change can be a powerful driver of the net greenhouse gas emissions of a sustainable production system. Yet the net climate change mitigation of managed forests is affected by both tradeoffs between C sequestration and non-renewable C emissions and assessment methodology. As a case study, we measured ecosystem stocks to determine the potential C implications of converting pasture to managed eucalyptus forest and compared them with the eucalyptus production system's non-renewable C emissions. The forest border was chosen as the system boundary and operations spanned from forest establishment activities to harvested wood placed at the forest perimeter. Eucalyptus biomass C was 57.2 ± 4.2 Mg C ha−1and soil C stock (to ∼1 m depth) was approximately an order of magnitude greater. By the prevalent method for bulk density-based determination of C stock, conversion of pasture to eucalyptus forest significantly increased soil C stock by 17.5 ± 8.0%. However, no significant change was detected by the equivalent soil mass method, a less prevalent but more accurate approach to detecting differences in soil C stock due to land use or management changes. A 7-year eucalyptus production cycle generated 1.0 Mg C ha−1in non-renewable emissions, which was far exceeded by the tree biomass C. Thus, even without significant soil C sequestration, this system provided a substantial climate change mitigation service by offsetting non-renewable energy use and C emissions associated with wood production, and providing opportunities for biofuel and bioenergy products to displace fossil fuel products. [ABSTRACT FROM AUTHOR]

While the eddy covariance technique has become an important technique for estimating long-term ecosystem carbon balance, under certain conditions the measured turbulent flux of carbon at a given height above an ecosystem does not represent the true surface flux. Profile systems have been deployed to measure periodic storage of carbon below the measurement height, but have not been widely adopted. This is most likely due to the additional expense and complexity, and possibly also the perception - given that net storage over intervals exceeding 24 hours is generally negligible - that these measurements are not particularly important. In this study, we used a three year record of net ecosystem exchange of carbon and simultaneous measurements of carbon storage to ascertain the relative contributions of turbulent carbon flux, storage and advection (calculated as a residual quantity) to the nocturnal carbon balance, and to quantify the effect of neglecting storage. The conditions at the site are in relative terms highly favourable for eddy covariance measurements, yet we found a substantial contribution (~ 40%) of advection to nocturnal turbulent flux underestimation. The most likely mechanism for advection is cooling-induced drainage flows, the effects of which were observed in the storage measurements. The remaining ~ 60% of flux underestimation was due to storage of carbon. We also showed that substantial underestimation of carbon uptake (approximately 80 gC m-2 a-1, or 25% of annual carbon uptake) arose when standard methods of nocturnal flux correction were implemented in the absence of storage estimates. These biases were much larger than quantifiable uncertainties in the data. Neglect of storage also distorted the relationships between the carbon exchange processes (respiration and photosynthesis) and their key controls (light and temperature, respectively). We conclude that addition of storage measurements to eddy covariance sites with all but the lowest measurement heights should be a high priority for the flux measurement community. [ABSTRACT FROM AUTHOR]

Well-drained, aerated soils are important sinks for atmospheric methane (CH4) via the process of CH4 oxidation by methane oxidising bacteria (MOB). This terrestrial CH4 sink may contribute towards climate change mitigation, but the impact of changing soil moisture and temperature regimes on CH4 uptake is not well understood in all ecosystems. Temperate eucalypt forests in south-eastern Australia are predicted to experience rapid and extreme changes in rainfall patterns, temperatures and wild fires. To investigate the influence of environmental drivers on seasonal and inter-annual variation of soil-atmosphere CH4 exchange we measured soil-atmosphere CH4 exchange at high temporal resolution (< 2 hr) in a dry temperate eucalypt forest in Victoria (Wombat State Forest, 870 mm yr-1) and in a wet temperature eucalypt forest in Tasmania (Warra LTER, 1700 mm yr-1). Both forest soil systems were continuous CH4 sinks of -1.79 kg CH4 ha 1 yr-1 in Victoria and -3.83 kg CH4 ha-1 yr-1 in Tasmania. Soil CH4 uptake showed substantial temporal variation and was strongly controlled by soil moisture at both forest sites. Soil CH4 uptake increased when soil moisture decreased, and this relationship explained up to 90% of the temporal variability. Furthermore, the relationship between soil moisture and soil CH4 flux was near identical at both forest sites when soil moisture was expressed as soil air-filled porosity (AFP). Soil temperature only had a minor influence on soil CH4 uptake. Soil nitrogen concentrations were generally low, and fluctuations in nitrogen availability did not influence soil CH4 uptake at either forest site. Our data indicate that soil MOB activity in the two forests was similar and that differences in soil CH4 exchange between the two forests were related to physiochemical differences in soil properties influencing soil gas diffusivity. The differences between forest sites and the variation in soil CH4 exchange over time could be explained by soil air-filled porosity as an indicator of soil moisture status. [ABSTRACT FROM AUTHOR]

Key message : Log-end splitting is one of the single most important defects in veneer logs. We show that log-end splitting in the temperate plantation species Eucalyptus nitens varies across sites and within-tree log position and increases with time in storage. Context : Log-end splitting is one of the single most important defects in veneer logs because it can substantially reduce the recovery of veneer sheets. Eucalyptus nitens can develop log-end splits, but factors affecting log-end splitting in this species are not well understood. Aims : The present study aims to describe the effect of log storage and steaming on the development of log-end splitting in logs from different plantations and log positions within the tree. Methods : The study was conducted on upper and lower logs from each of 41 trees from three 20-22-year-old Tasmanian E. nitens plantations. Log-end splitting was assessed immediately after felling, after transport and storage in a log-yard, and just before peeling. A pre-peeling steam treatment was applied to half the logs. Results : Site had a significant effect on splitting, and upper logs split more than lower logs with storage. Splitting increased with tree diameter breast height (DBH), but this relationship varied with site. The most rapidly growing site had more splitting even after accounting for DBH. No significant effect of steaming was detected. Conclusion : Log-end splitting varied across sites and within-tree log position and increased with time in storage. [ABSTRACT FROM AUTHOR]

Fertilization increases productivity in Eucalyptus plantations, but losses in productivity associated with soil fertility continue at operational scales. In this study, we evaluated the fertilization response (FR), light use efficiency (LUE) and growth efficiency (GE), i.e., the amount of wood biomass accumulated per unit of light absorbed (LUE) and per unit of leaf area index of Eucalyptus plantations. We used a "twin plot" approach, with 161 blocks representing 52,700 ha of planted forests that spanned a broad range of edaphoclimatic conditions in southeastern Brazil. The normal plots (NP) were part of a permanent inventory network, whereas the twin plots (TP) received extra high levels of fertilization and extra weed control after fertilization. The intensive management (twin plots) led to a large increase of 5.3 Mg· ha–1· year–1 of wood increment. The region without dry periods and with soils with high clay content was most responsive to fertilization, with a 15% increment in the LUE and 10% increase in the GE of the TPs compared with those of the NPs. Our results suggested that water availability was the primary element affecting productivity and potential response to fertilization. With this information, decisions can be made on which regions should receive priority fertilization investments. However, more research is required to determine the most limiting nutrient in each type of environment. [ABSTRACT FROM AUTHOR]

Questions: Climate change-type drought (the combination of drought and heatwave) has become a widely documented driver of forest dieback yet, to date, limited measurement of post-event forest dynamics has been reported. Can climate change-type drought trigger structural and/or compositional changes in a forest type which is usually highly resilient to other disturbances? Location: Mixed Eucalyptus forest in southwestern Australia. Methods: Forest areas that were severely and minimally affected by drought were measured repeatedly at 3, 6, 16, 26 and 49 mo post-event for changes in forest structure and composition of the two dominant tree species (Eucalyptus marginata/ Corymbia calophylla). Means and dispersal from pre-drought conditions were analysed for each structural variable among drought severity classes and between measurement periods. Resprouting, the predominant resilience mechanism in Eucalyptus, was assessed at 6 and 16 mo, while regeneration type and density were determined at 16 mo post-drought. Results: Structural changes were observed after 49 mo on plots severely but not minimally affected by drought, including a 30% increase in stem density (P < 0.0001) and reduction in tree diameter (23%; P < 0.01), basal area (33%; P < 0.0001), canopy height (40%; P < 0.0001) and live biomass (36%; P = 0.01). On severely affected plots, all structural variables plateaued at levels different from pre-drought conditions. Large, old trees on severely affected plots were replaced by high densities of small stems (1-10 cm DBH). Resprouting among drought affected trees (P < 0.001) and tree regeneration (P = 0.02) were higher on severely affected plots. No significant shifts in the proportional abundance of the two dominant species, E. marginata and C. calophylla, were observed for structural attributes or regeneration after 49 mo. Conclusion: Climate change-type drought can cause structural shifts in a resproutingmediterranean-type forest, providing evidence for a shift to an alternate state, particularly with repeated disturbance. While the study area showed low structural resistance and resilience, tree species composition was resilient to change, as E. marginata is likely to remain dominant in the future due to its resprouting capacity. Findings support the view that climate change-type drought will drive replacement of large trees with short,multi-stemmed individuals, transforming ecosystem structure. [ABSTRACT FROM AUTHOR]

Over the past decades, wildfires have affected vast areas of Mediterranean ecosystems leading to a variety of negative on- and off-site environmental impacts. Research on fire-affected areas has given more attention to sediment losses by fire-enhanced overland flow than to nutrient exports, especially in the Mediterranean region. To address this knowledge gap for post-fire losses of phosphorus (P) by overland flow, a recently burnt forest area in north-central Portugal was selected and instrumented immediately after a wildfire. Three slopes were selected for their contrasting forest types (eucalypt vs. pine) and parent materials (granite vs. schist). The selected study sites were a eucalypt site on granite (BEG), a eucalypt site on schist (BES) and a maritime pine site on schist (BPS). Micro-plots were monitored over a period of six months, i.e. till the construction of terraces for reforestation obliged to the removal of the plots. During this 6-month period, overland flow samples were collected at 1- to 2-weekly intervals, depending on rainfall. Total P and PO 4 -P losses differed markedly between the two types of forests on schist, being lower at the pine site than at the eucalypt site, probably due to the presence of a protective layer of pine needle cast. Parent material did not play an important role in PO 4 -P losses by overland flow but it did in TP losses, with significantly lower values at the eucalypt site on granite than that on schist. These differences in TP losses can be attributed to the coarser texture of granite soils, typically promoting infiltration and decreasing runoff. The present findings provided further insights into the spatial and temporal patterns of post-fire soil nutrient losses in fire-prone forest types during the initial stages of the window-of-disturbance, which can be useful for defining post-fire emergency measures to reduce the risk of soil fertility losses. [ABSTRACT FROM AUTHOR]

Current theory presumes that natural selection on vascular traits is controlled by a trade-off between efficiency and safety of hydraulic architecture. Hence, traits linked to efficiency, such as vessel diameter, should show biogeographic patterns; but critical tests of these predictions are rare, largely owing to confounding effects of environment, tree size and phylogeny. Using wood sampled from a phylogenetically constrained set of 28 Eucalyptus species, collected from a wide gradient of aridity across Australia, we show that hydraulic architecture reflects adaptive radiation of this genus in response to variation in climate. With increasing aridity, vessel diameters narrow, their frequency increases with a distribution that becomes gradually positively skewed and sapwood density increases while the theoretical hydraulic conductivity declines. Differences in these hydraulic traits appear largely genotypic in origin rather than environmentally plastic. Data reported here reflect long-term adaptation of hydraulic architecture to water availability. Rapidly changing climates, on the other hand, present significant challenges to the ability of eucalypts to adapt their vasculature. [ABSTRACT FROM AUTHOR]

The growth of intact plants and coppice of juvenile plants of eight eucalypt clones (3 × 3 m spacing) was evaluated in the savanna region, Brazil (17°36′09″S and 46°42′02″W), aiming for biomass production for energy in short rotations. The treatments included intact plants and juvenile plant coppice (cut at 13 months of age). Coppice was managed either with thinning to two sprouts/stump at 9 months after harvesting or without sprout thinning. The diameter of the intact plants was greater than that of coppice for clones 58, GG100, 26 and 8B, and no differences were noted between treatments for the other clones. Yield did not differ between the thinned and unthinned sprouts for most clones. At younger ages, the coppice yield was greater than that of the intact plants for most clones. Later, there was a decline in the coppice yield, and intact plants surpassed coppice. Then, the maximum coppice mean annual increment was achieved at younger ages than for the intact plants, which resulted in coppice rotation age shortening. The greatest differences between the coppice and intact plants yield was between 38 and 40 months, when the coppice yield was 59, 56, 127, 149 and 75 % greater than that of the intact plants, for the clones 58, GG100, 1000, 36 and 910, respectively. Clone GG100 revealed the highest yield estimation among the intact and coppice plants. The results indicate that by coppicing juvenile eucalypt clone plants, in dense stands, it is possible to produce biomass for energy, without sprout thinning, if rotation age is shortened. [ABSTRACT FROM AUTHOR]

We examined the change in spatial structures of Eucalyptus plantations across different types of silvicultural treatments over a full rotation. Clonal and seed-origin Eucalyptus plots applied with differing levels of fertilization (high vs. traditional) and irrigation (irrigated vs. non-irrigated) treatments were investigated. Additionally, for the clonal plots, uniform vs. heterogeneous stand structure treatments were created using staggered planting dates. The heterogeneous structure of the clonal plots aimed to mimic the seed-origin plots. Spatial structures were characterized by assessing the spatial autocorrelations of diameters, heights, and biomass. We also applied two distance-based neighborhood structures to look at the degree of change in spatial autocorrelations with different numbers of neighboring trees being defined as neighbors. The results suggest that spatial autocorrelations of diameters, heights, and biomass of Eucalyptus plantations were mostly insignificant at an alpha level of 0.05 over the rotation. However, spatial autocorrelations in most plots after the middle of the rotation were predominantly negative, indicating the occurrence of size differences among neighboring trees. In particular, general declining patterns from positive to negative spatial autocorrelations in diameters and biomass, except for plots with the heterogeneous stand structures, were noted at plots treated with high levels of fertilizer. This suggests that high fertilization may have influenced the realizations of microsite effects in the early stage of stand development. General trends in spatial autocorrelations between the two neighborhood structures considered were mostly similar except for several plots differing in intensities of spatial autocorrelations over the rotation. [ABSTRACT FROM AUTHOR]

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In this study, systematic variation in tree morphology across a rainfall gradient in Australia's tropical savanna biome and its implications for carbon stocks and dynamics were quantified. The aim was to support efforts to manage fire regimes to increase vegetative carbon stocks as a greenhouse gas mitigation strategy. The height of trees for a given trunk diameter declines with decreasing rainfall from 2000 to 300 mm and increasing dry season length across the Australian savanna biome. It is likely that increasing dry season length is the main driver of this decline rather declining rainfall per se. By taking account of the response of total basal area to rainfall and soil type, stand structure, and tree height and diameter relationships, the carbon stocks in live trees were estimated to decline from about 34 t ha−1 in the wetter savannas to 6 t ha−1 in the drier savannas. These values are broadly consistent with field-based estimates. Because of the declining ratio of height to trunk diameter, trees of a given diameter in drier regions will be more likely to be killed by fires of a given intensity than trees in wetter regions. Thus single fires of given intensity are likely to have a greater proportionate impact on live tree carbon stock in drier savannas, but a much greater absolute impact in wetter savannas due to the greater total carbon stock. Projected decreases in early wet season rainfall under climate change scenarios, despite projections of little change in total precipitation in northern Australia, may lead to decreased carbon stock in live trees through two mechanisms: a reduction in total basal area and decreases in tree height for given trunk diameters. [ABSTRACT FROM AUTHOR]

The major focus of ecological restorations has been on understanding local factors. However, landscape factors such as dispersal limitation of individuals or propagules across the surrounding matrix can also constrain the restoration progress. We investigated to what extent native woody species colonize and thrive in plantations, focusing on both the role of local factors such as grazing and canopy cover as well as on landscape factors. We recorded all native tree and shrub species in 60 small Eucalyptus plantations embedded in an open agricultural landscape at 0.1-12 km from a remnant continuous forest in central Ethiopia. We found a total of 1,571 individuals of native woody plants belonging to 55 species. Number of such species in a plantation increased significantly with the height of the grass sword indicating their sensitivity to grazing. Moreover, the number of woody species in the patches decreased significantly with distance to the forest. Our results illustrate the need for regulating the grazing pressure for a successful regeneration of native species in Eucalyptus plantations. In addition, sowing or planting native trees will be necessary in most plantations, as only few remnant natural forests that could act as seed sources occur across the Ethiopian highlands. Another main obstacle might be the prohibition of selling timber of native trees, which indirectly discourage farmers from letting native trees regenerate. Thus, the increasing cover of Eucalyptus seen across the country will not automatically foster a recovery of native woody plant biodiversity, even if managed to optimize local environmental conditions. [ABSTRACT FROM AUTHOR]