Many aquatic habitats in coastal Oregon have been impacted by historic land use practices that led to losses of in-stream wood and associated degraded fish habitats. Many of these streams are now bordered by stands of dense second growth forests (30–80 years) that are incorporated into riparian buffer zones with low wood recruitment and storage. Thinning in riparian zones is one management option to increase the rate of large tree growth and eventually larger in-stream wood, however, it raises concern about impacts on current wood recruitment, among other issues. Using a forest growth simulation model coupled to a model of in-stream wood recruitment, we explore riparian management alternatives in a Douglas-fir plantation in coastal Oregon. Alternatives included: (1) no treatment, (2) single and double entry thinning, without and with a 10-m buffer, and (3) thinning combined with mechanical introduction of some portion of the thinned trees into the stream (tree tipping). Compared to no treatment, single and double entry thinning on one side of a channel, without a 10-m buffer, reduce cumulative in-stream wood volume by 33 and 42 %, respectively, after 100 years (includes decay). Maintaining a 10-m buffer reduces the in-stream wood loss to 7 % (single entry thin) and 11 % (double entry). To completely offset the losses of in-stream wood in a single entry thin (on one or both sides of the stream), in the absence or presence of a 10-m buffer, requires a 12–14 % rate of tree tipping. Relative to the no-treatment alternative, cumulative in-stream wood storage can be increased up to 24 % in a double-entry thin with no buffer by tipping 15–20 % of the thinned trees (increased to 48 % if thinning and tipping simultaneously on both sides of the stream). The predicted increases in in-stream wood that can occur during a thin with tree tipping may be effective for restoring fish habitat, particularly in aquatic systems that have poor habitat conditions and low levels of in-stream wood due to historic land use activities.

The objective was to evaluate the performance of the co-management of Nishorgo Support Project at Chunati Wildlife Sanctuary in Bangladesh. I adopted the Focus Groups Discussion method for opinion survey and applied the SWOT-AHP technique for data analysis. Local people did not participate in the decision-making process of forest management and they perceived co-management as a threat to their livelihoods. Moreover, mistrust and misunderstanding among different stakeholders, political and ethical conflicts, lack of property rights of tribal communities, and lack of accountability and transparency were identified as the drawbacks of co-management.

Platycladus orientalis is one of the most popular afforestation species and greening species for water management in arid and semi-arid regions of northern China. We applied various models to estimate and validate artificial P. orientalis forest evapotranspiration features with the goal of accurately estimating the water use of a P. orientalis plantation. The American Society of Civil Engineers Evapotranspiration–Penman–Monteith model (APM) and FAO56–Penman–Monteith model (FPM) are extensively applied for vegetation evapotranspiration estimation because their reliability has been validated by many scholars. The Priestley–Taylor model (PT) and Hargreaves model (HS) require only the daily maximum temperature, daily minimum temperature and solar radiation to estimate evapotranspiration and are thus widely applied to grasslands but not to forests. We used the Energy Balance Bowen Ratio (EBBR) system to validate the accuracy of the four models. The results indicated that: (1) Compared to the EBBR measurement annual value, APM was the most accurate, followed by FPM, and PT; (2) During the year, the accuracies of the four models varied. APM and FPM underestimated evapotranspiration during June, July and August, whereas PT and HS overestimated evapotranspiration during this period. In the rest of the year, the estimation accuracies were reversed; (3) An analysis of the possible reasons indicated that wind speed, air temperature and precipitation were the most important contributors. High temperatures were measured in June, July and August, which led to an overestimation by PT and HS because these two models only calculated the temperature and radiation without vegetation information. Underestimation also occurred when a low temperature was recorded. Though APM and FPM addressed both meteorological and vegetation factors, slight deviations still existed; and (4) The two models were modified based on EBBR-measured data. Relative humidity was introduced into PT, and parameter “A” in the HS estimation model was amended to 1.41. The accuracy of the modified models significantly increased. The study highlighted the application, comparison and improvement of four models in estimating evapotranspiration and offers more approaches to assess forest hydrological functions.

The prediction of the distribution of quantitative variables in a forest stand is of great interest to forest managers, for the evaluation of forest resources and scheduling of future silvicultural treatments. The aim of this research was to model the distribution of quantitative variables for Quercus persica in open forests in Iran. To investigate the probability distribution of trees in natural stands, 642 trees were selected for measurement using a systematic random sampling method. Selected trees were measured and data were analyzed. Gamma, beta, normal, lognormal, exponential and Weibull probability distributions were fitted to the height distribution of trees. Variables of distribution functions were estimated using the maximum likelihood estimation method. Actual probability and probability which derived from functions was compared using Kolmogorov–Smirnov and Anderson–Darling tests. Beta, Weibull and Weibull probability distributions explained the distributions of tree height, DBH and crown area.

In the context of global carbon cycle management, accurate knowledge of carbon content in forests is a relevant issue in contemporary forest ecology. We measured the above-ground and soil carbon pools in the dark-coniferous boreal taiga. We compared measured carbon pools to those calculated from the forest inventory records containing volume stock and species composition data. The inventory data heavily underestimated the pools in the study area (Stolby State Nature Reserve, central Krasnoyarsk Territory, Russian Federation). The carbon pool estimated from the forest inventory data varied from 25 (t ha⁻¹) (low-density stands) to 73 (t ha⁻¹) (highly stocked stands). Our estimates ranged from 59 (t ha⁻¹) (low-density stands) to 147 (t ha⁻¹) (highly stocked stands). Our values included living trees, standing deadwood, living cover, brushwood and litter. We found that the proportion of biomass carbon (living trees): soil carbon varied from 99:1 to 8:2 for fully stocked and low-density forest stands, respectively. This contradicts the common understanding that the biomass in the boreal forests represents only 16–20 % of the total carbon pool, with the balance being the soil carbon pool.

Microbe communities in rhizosphere ecosystems are important for plant health but there is limited knowledge of them in the rhizospheres of genetically modified (GM) plants, especial for tree species. We used the amplitude sequencing method to analyze the V4 regions of the 16S rRNA gene to identify changes in bacterial diversity and community structure in two GM lines (D520 and D521), one non-genetically modified (non-GM) line and in uncultivated soil. After chimera filtering, 468.133 sequences in the domain Bacteria remained. There were ten dominant taxonomic groups (with >1 % of all sequences) across the samples. 241 of 551 genera (representing a ratio of 97.33 %) were common to all samples. A Venn diagram showed that 1.926 operational taxonomic units (OTUs) were shared by all samples. We found a specific change, a reduction in Chloroflexi, in the microorganisms in the rhizosphere soil planted with poplars. Taken together, the results showed few statistical differences in the bacterial diversity and community structure between the GM line and non-GM line, this suggests that there was no or very limited impact of this genetic modification on the bacterial communities in the rhizosphere.

Chitosan is a natural biopolymer, derived from chitin, which is used for wood modification. Polyethylene glycol (PEG) was reacted with wood to provide possible fixation of the chitosan to wood. Wood blocks were treated with chitosan and PEG, as well as pre-treatment with the PEG at different temperatures and further reaction with the chitosan. The samples were soaked in water to study leaching of the chemicals, water absorption, swelling, as well as anti-swelling efficiency. Any prior reaction of the wood with PEG provided better reaction to the chitosan. Bulking was increased after the treatment of the wood with PEG. Swelling was reduced in the PEG-treated wood blocks as well as the pre-treated samples. Chitosan was not able to protect wood against water penetration: the treated samples showed more water absorption and swelling. However, pre-treatment of the samples decreased swelling in the wood, and the density was not noticeably affected by the treatments. Heating during the treatment caused more reduction in swelling for PEG–chitosan treated samples.