Fully mechanized timber harvesting systems are generally characterized by a high operational performance being widespread and used across many regions. Such systems are adaptable to different levels of operational integration, enabling also the recovery of energy wood, but given integration configurations affect their performance. A production study was carried out in a Norway spruce clear-cut aiming to investigate the performance of a mid-sized harvester-forwarder system in general, and the effect that fuelwood recovery from tree tops may have on its performance. Data was collected in the field during 11 days of observation using state-of-art equipment and software. Harvester’s operations were monitored using a digital camera. Data refined from 27.5 filmed hours that accounted for 1045 felled and fully processed trees was used to model and compute its performance indicators. In addition, fuel consumption data was sampled in the field. The results indicated that a delay-free cycle time consumption was affected by variables characterizing the tree size. The net production rate was estimated to about 26.5 m3 ∙ h-1, being substantially affected by supplementary tree-top processing. Forwarding operations were monitored using a handheld computer and a Global Positioning System unit. The delay-free cycle time consumption was affected by forwarding distance and the amount of loaded wood, resulting in a net production rate of about 19.2 m3 ∙ h-1. Under these circumstances, the forwarding performance matched the harvester’s outputs for an extraction distance of about 100 m, indicating that the supplementary processing of the tree-tops had no effect on the system’s productive performance in the studied conditions. Most likely, it affected the harvester’s fuel consumption given its proportion of 9% in the delay-free harvester’s cycle time. The results also indicated a mean fuel consumption of about 1.7 l ∙ m-3 for the studied harvesting system.

Dipteryx alata (Fabaceae) is a threatened tropical tree of the Brazilian Savanna. Due to deforestation of its biome, many individuals and populations are now spatially isolated in forest fragments, pastures, and along roads. Plans for in situ and ex situ conservation of the species are urgently needed. To support conservation, the mating system and pollen dispersal patterns must be better understood as they determine the levels of genetic diversity, inbreeding, and effective size of seed generations. Microsatellite were used to investigated the mating system, pollen dispersal, genetic diversity, spatial genetic structure (SGS), and inbreeding in isolated trees in pastures and along roads from two populations with different densities in the Brazilian Savanna. Our aim is to determine the potential of these trees to contribute to seed collection for genetic conservation. We found that the species presents a mixed mating system, strong individual variation in outcrossing rate (0.01-1.0), and non-random mating. Low population density resulted in lower levels of outcrossing (tm = 0.45) and mating among relatives (tm - ts = 0.12), but longer pollen dispersal distances (δ = 6,572 m) than in the higher density populations (tm = 0.90, tm - ts = 0.26, δ = 1,395 m). Mating among relatives was explained by SGS detected in the populations, associated with near-neighbor pollinator foraging behavior. Correlated mating indicates that a low effective number of pollen donors (1.5-10.3) fertilized the trees. Thus, open-pollinated seedling families present mixtures of different levels of relatedness and inbreeding. Our results are discussed in light of strategies for in and ex situ conservation.

Height–diameter (H–D) and stem volume equations are indispensable tools for forest management and have a wide use in forestry, however they are lacking for Lebombo-ironwood. Based on a dataset of 1144 Lebombo-ironwood trees destructively measured for height and stem volume, H–D and stem volume models were fitted using mixed-effects and dummy variables models. Random-effects and dummy variables were the different growing sites, as they affect H–D relationships and therefore stem volume models. Different model forms were compared to each other with regard to the sources of errors. The error due to uncertainty in the model parameter estimates was insignificant for mixed-effects models, whilst the error due to model misspecification was relatively larger for dummy variables H–D functions when compared to the mixed-effects ones. However, both mixed-effects and dummy variables models were similar in terms of error due to residual variability around model prediction. Overall, mixed-effects and dummy variables models did not differ in terms of predictive ability and accuracy.

Stable carbon and nitrogen isotopes can be influenced by a multitude of factors including elevation, precipitation rate, season, and temperature. This work examined the variability in foliar stable carbon (δ13C) and nitrogen (δ15N) isotope ratios of koa (Acacia koa) for 17 sites on Hawai’i Island delineated by elevation and precipitation gradients. Sites were identified and grouped with respect to mean annual precipitation (MAP), mean annual temperature (MAT) and position along three elevation ranges. Analysis of the resultant δ13C and δ15N isotope ratios from multiple individuals at these sites indicated that certain sites showed a demonstrated correlation between carbon and/or nitrogen content, isotope ratios, precipitation, and elevation however many sites showed no correlation. We used publicly available temperature and moisture data to help eliminate confounding effects by climatic drivers and capture possible points of contention. At sites where the temperature, precipitation, and elevation data were not significantly different we compared stable isotope information to determine if additional variables could have contributed to the lack of more correlative data. Our results note several areas within the Waiakea Forest Reserve and Volcanoes National Park where, based on isotope results, reforestation efforts could be most successfully initiated.

Lidar (light detection and ranging) remote sensing technology provides promising tools for 3D characterization of the earth’s surface. In ecosystem studies, lidar derived structural parameters relating to vegetation and terrain have been extensively used in many applications and are rapidly expanding. Yet, most of the lidar applications have focused on tall, woody vegetation in forested environments and less research attention is given to non-forest, short stature vegetation dominated ecosystems. Similar to the lidar developments in forestry, novel methodological approaches and algorithm developments will be necessary to improve estimates of structural and biophysical properties (i.e. biomass and carbon storage) in non-forested short stature environments. Under changing climate scenarios, the latter is particularly useful to improve our understanding of their future role as terrestrial carbon sinks. In an attempt to identify research gaps in airborne lidar remote sensing application in short stature vegetation studies, in this review article we provide a comprehensive overview on the current state of airborne lidar applications. Our focus is mainly on the levels of accuracies and errors reported, as well as the potentials and limitations of the methods applied in these studies. We also provide insights into future research needs and applications in these environments.

The importance of this study consists in the knowledge of the ecological attributes characteristic to mixed forestry habitats and how they affect the structure of the lichen species abundances. The field activities were performed within five forest habitat types from Moldavia Province, characterised mainly by oak mixed forests, riparian mixed forests and mixed beech forests. The habitat variables, tree variables and the lichen species abundances were analysed to get informations on the structural disimilarities, on the one hand, and relationships on the other hand. Within this study no significant disimilarities were found out from abundance lichen species point of view. The lichen species abundances are a result of interactions between components of their microhabitat and macrohabitat. The correlation analysis pointed out the preferences of lichen species to their host trees, especially Quercus and Fraxinus, altitude and tree level variables as are aspect and mosses coverage. The regression analysis has highlighted that the changes in lichen species abundances are caused by macrohabitat level predictors such as host trees represented by Fraxinus. This study demonstrates that, structure of lichen species is influenced by attributes of mixed forest habitats; therefore maintaining the diversity of tree species and ensuring the continuous occurrence of forestry land is necessary for lichen and their habitat conservation.

The occurrences of phenological events are important variables in the evaluation of the influence of climate change on terrestrial ecosystems. Changes in climate can cause significant changes in the timing and duration of phenological events. Information related to large-scale phenology is therefore useful for exploring the seasonal and inter-annual variability in vegetation-climate interactions. This study aimed to obtain the timing and temporal pattern of the onset of green-up and dormancy (OG and OD) and length of growing season (LGS) using the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) for Forest, Grassland, and Desert steppe in Mongolia over the 10-year period from 2000 to 2009. Results demonstrated that phenological events can be differentiated by multi-temporal NDVI and EVI data and that the timing ascribed to OG and OD is slightly different between the two indices. In general, NDVI and EVI agreed that the OG of forest varied from late May to middle July. The OG of grassland and desert steppe suggested by NDVI were from late May to middle July and from middle May to middle July respectively, however EVI suggested an earlier timing of OG. NDVI and EVI also showed similar variation for the timing of OD from early September to early October. The derived LGS showed the least variation for forest, highest variation for desert steppe, and only moderate variation for grassland. Grassland and desert steppe experienced high positive and negative variations in the OG and LGS during the years from 2000 to 2009. These regions might be vulnerable to global change and are likely to be strongly affected by meteorological changes.

Teak (Tectona grandis) is one of the highly demanded timber species in Sri Lanka. When buying teak logs, customers assess their quality by visual appraisal of surface characteristics such as visible defects. Hence, the buyers’ preference for logs with desired attributes is reflected by the price achieved in the market. In this study, we examined the influence of visually observable quality attributes of plantation grown teak logs on their market price. A set of 650 randomly selected teak logs were assessed for dimensions, shape defects, surface defects and end-defects. Length of the log, mid-circumference (under bark), diameter at top-end and butt-end, number of knots per meter, average diameter of the knots, bend fraction, percentage of heartwood, shape of the log, presence of buttress, position of the hollows, presence of felling damages, splits and heart rot were recorded using standard methods. Selling prices of logs were obtained from the records of log storing facilities. By using the multiple linear regressions, a price-quality model was developed to explain the impact of quality attributes on sellingprice. The regression model achieved a strong coefficient of determination (R2) of 0.87. Accordingly, the length, mid-circumference, number of knots per meter, bend fraction, hollow position, presence of buttresses and presence of heart rot were found to have a significant influence on the price. The relative price reduction due to presence of a specific log defect was further examined using the derived price-quality model. The presence of high number of knots had the highest detrimental impact on price, followed by the higher bend fraction, presence of hollows at top end and/or middle of the log, presence of heart rot and presence of buttresses respectively. These findings have implications in the improved management of teak plantations.

The pioneer tree black locust (Robinia pseudoacacia L.) is a drought-resistant tree and, in symbiosis with Rhizobium, able to fix dinitrogen from the atmosphere. It is, therefore, an interesting species for marginal lands where soil amelioration is sought in addition to economic gain. However, the interaction between soil water availability, carbon allocation and nitrogen fixation is important for a successful establishment of trees on marginal lands and has not yet been investigated for black locust. Twoyear-old trees were grown under various soil water conditions and drought cycles. The stable isotopic composition of C (δ 13C) and N (δ 15N) of the leaves was used to identify i) the effective drought condition of the treatments and ii) the portion N accrued from the atmosphere by the biological nitrogen fixation. Drought-stressed plants significantly reduced their total aboveground biomass production, which was linearly linked to tree transpiration. The shoot:root ratio values changed from 2.2 for the drought-stressed to 4.3 for the well-watered plants. Our investigation shows that drought stress increases the nodule biomass of black locust in order to maintain biological nitrogen fixation and to counteract the lower soil nitrogen availability. The biological nitrogen fixation of drought-stressed trees could be maintained at relatively higher values compared to the well-watered trees. The average leaf nitrogen content varied between 2.8% and 3.0% and was not influenced by the drought stress. Carbon fixation, carbon allocation, and biological nitrogen fixation are to some extent balanced at low irrigation and allow Robinia to cope with long-term water constraints. The combination of black locust’s ecophysiological and morphological plasticity make it interesting as a biomass source for bioenergy and timber production, even in nutrient-limited and drought-affected areas of Europe.

Medinilla formosana Hayata, a beautiful endangered shrub of the family Melastomataceae endemic in Taiwan of China, is recalcitrant for micropropagation in vitro until now. And tissue browning after cutting generally occurred in the tissue culture of Medinilla species was considered to be the greatest obstacle. To avoid the serious cut-browning, immature ovaries in 0.3 cm diameter of M. formosana were taken as initial explants in this study, and its aseptic plantlets were obtained for the first time. The highest survival level (12.7 plantlets per ovary) after 3 months of culture were observed on 1/2 MS supplemented with 0.5 g l-1 active carbon and 0.4 g l-1 casein hydrolysate (pH 5.5). Furthermore, β-mercaptoethanol proved to be an effective inhibitor for its browning response of M. formosana in vitro. And 1/2 MS media supplemented with 6.67 μM BA, 0.11 μM NAA, 0.5 mM β-Met and 0.2 g l-1 AC proved appropriate for its multiplication. Finally rooted plantlets were transplanted into the greenhouse after acclimatization, and the micropropagation system of M. formosana was successfully established. This report first details an efficient method for the in vitro micropropagation of Medinilla plants.