Journal of Northeast Forestry University

Cold-resistance pathways that operate in model plants such as Arabidopsis thaliana and Oryza sativa have been studied extensively. It has been found that CBF genes play an important role in plant cold resistance. Liriodendron chinense, a tree known for its graceful tree shape and widely spread in south China, has weak cold tolerance. However, little is known about its response to cold. To further study the function of L. chinense CBF gene family, we started by characterizing all members of this gene family in the L. chinense genome and their expression profiling. Phylogenetic analysis found that 14 CBF genes in L. chinense are more closely related to their homologues in woody plants and A. thaliana than those in O. sativa. Cis-acting elements and GO analysis showed that some LcCBF genes participated in the biological process of cold stress response. The transcriptomic and RT-qPCR data showed that most of LcCBF genes displayed an initially increasing and subsequently decreasing trend during cold stress course and the expression profile of each member was different. Some LcCBF genes exhibited a different abundance in callus, root, stem and leaf tissues. The structure and expression characteristics of LcCBF genes imply that they may have similar and different functions in response to cold stress conditions. The identification and analysis of LcCBF gene family have laid the foundation for future studies into L. chinense cold stress mechanisms and for the cultivation of cold-resistance cultivars.

Eucalypts are important forest resources in southwestern China, and may be tolerant to elevated ground-level ozone (O3) concentrations that can negatively affect plant growth. High CO2 may offset O3-induced effects by providing excess carbon to produce secondary metabolites or by inducing stomatal closure. Here, the effects of elevated CO2 and O3 on leaf secondary metabolites and other defense chemicals were studied by exposing seedlings of Eucalyptus globulus, E. grandis, and E. camaldulensis × E. deglupta to a factorial combination of two levels of O3 (< 10 nmol mol−1 and 60 nmol mol−1) and CO2 (ambient: 370 μmol mol−1 and 600 μmol mol−1) in open-top field chambers. GC-profiles of leaf extracts illustrated the effect of elevated O3 and the countering effect of high CO2 on compounds in leaf epicuticular wax and essential oils, i.e., n-icosane, geranyl acetate and elixene, compounds known as a first-line defense against insect herbivores. n-Icosane may be involved in tolerance mechanisms of E. grandis and the hybrid, while geranyl acetate and elixene in the tolerance of E. globulus. Elevated O3 and CO2, singly or in combination, affected only leaf physiology but not biomass of various organs. Elevated CO2 impacted several leaf traits, including stomatal conductance, leaf mass per area, carbon, lignin, n-icosane, geranyl acetate and elixene. Limited effects of elevated O3 on leaf physiology (nitrogen, n-icosane, geranyl acetate, elixene) were commonly offset by elevated CO2. We conclude that E. globulus, E. grandis and the hybrid were tolerant to these O3 and CO2 treatments, and n-icosane, geranyl acetate and elixene may be major players in tolerance mechanisms of the tested species.

We studied the species diversity of the herb layer and ecological factors in harvest-created gaps in beech stands under a single-tree selection system in Northern Iran. To determine diversity, the number of beech seedlings, and other ecological factors, 16 gaps were selected and subplots of 5 m2 were positioned at the centre and at the cardinal points of each gap. Species richness and Simpson diversity index increased with increasing gap area as did numbers of seedlings. With increasing humus layer thickness, species richness declined but the Hill evenness index increased. Species richness increased with increasing light availability. There was no relationship between crown radii of beech trees and diversity indices. Correlations between environmental factors and numbers of individuals of some species in the herb layer were not significant except in a few cases. The results help explain the effects of man-made gaps on the dynamics of managed beech stands and this benefits evaluation of silvicultural operating plans.

Determining the physical and mechanical properties of soil and its behavior for engineering projects is essential for road construction operations. One of the most important principles in forest road construction, which is usually neglected, is to avoid mixing organic matter with road materials during excavation and embankment construction. The current study aimed to assess the influence of organic matter on the physical properties and mechanical behaviors of forest soil and to analyze the relation between the amount of organic matter and the behavior of forest soil as road material. A typical soil sample from the study area was collected beside a newly constructed roadbed. The soil was mixed with different percentages of organic matter (control treatment, 5, 10, and 15% by mass) and different tests including Atterberg limits, standard compaction, and California bearing ratio (CBR) tests were conducted on these different soil mixtures. The results showed that soil plasticity increased linearly with increasing organic matter. Increasing the organic matter from 0% (control) to 15% resulted in an increase of 11.64% of the plastic limit and 15.22% of the liquid limit after drying at 110 °C. Also, increasing the organic matter content reduced the soil maximum dry density and increased the optimum moisture content. Increasing the organic matter from 0 to 15% resulted in an increase of 11.0% of the optimum moisture content and a decrease of 0.29 g/cm3 of the maximum dry density. Organic matter decreased the CBR, which is used as the index of road strength. Adding 15% organic matter to the soil resulted in a decrease of the CBR from 15.72 to 4.75%. There was a significant difference between the two drying temperatures (60 and 110 °C) for the same organic matter mixtures with lower water content values after drying at 60 °C. The results revealed the adverse influence of organic matter on soil engineering properties and showed the importance of organic matter removal before excavation and fill construction.

Water harvesting is one of main measures to solve water shortage resulting from less precipitation and erratically seasonal distribution in arid and semi-arid areas. Different types of anti-infiltration treatments including mechanical and chemical to micro-catchment and their runoff efficiencies had been reported. This paper, through 5 years experiment from 1992 to 1996, is aimed at studying the impacts of microcatchment water-harvesting system (MCWHS) with microphytic crust treatment on afforestation on semi-arid Loess Plateau. The results showed that after 3 years of crust inoculation, crust had covered majority of MCWHS and the function of water harvesting had also been demonstrated partially, there were significant difference in soil moisture of shallow soil layer in three typical spring stages between crust cover and control treatments (0.05 level), and about 0.9%–6.04% increase of monthly mean soil moisture within 1m soil layer in spring of late 3 years. The impact of severe spring drought can be alleviated effectively. In the meanwhile, as crust developed on the treated surface, there are significant differences (0.05 level) for tree height (H), diameter at breast height (DBH) and diameter at ground level (DGL) at the end of the study period (1996) with the increases by 22.38%, 17.34%, and 20.49% respectively compared with the control treatment. Microphytic crust, as one of biological infiltration-proof materials, may become the optimized option for revegetation in Chinese Great West Development Strategy due to its self-propagation, non-pollution to water qualities, long use duration and relatively cost effective. Further work should be focused on the selection of endemic crust species and their batch-culture in arid environment.

Shelford's law of tolerance is illustrated by a bell-shaped curve depicting the relationship between environmental factor/factors’ intensity and its favorability for species or populations. It is a fundamental basis of ecology when considering the regularities of environment impacts on living systems, and applies in plant biology, agriculture and forestry to manage resistance to environmental limiting factors and to enhance productivity. In recent years, the concept of hormesis has been increasingly used to study the dose–response relationships in living organisms of different complexities, including plants. This requires the need for an analysis of the relationships between the hormetic dose–response model and the classical understanding of plant reactions to environments in terms of Shelford's law of tolerance. This paper analyses various dimensions of the relationships between the hormetic model and Shelford’s tolerance law curve under the influence of natural environmental factors on plants, which are limiting for plants both in deficiency and excess. The analysis has shown that Shelford’s curve and hormetic model do not contradict but instead complement each other. The hormetic response of plants is localized in the stress zone of the Shelford’s curve when adaptive mechanisms are disabled within the ecological optimum. At the same time, in a species range, the ecological optimum is the most favorable combination of all or at least the most important environmental factors, each of which usually deviates slightly from its optimal value. Adaptive mechanisms cannot be completely disabled in the optimum, and hormesis covers optimum and stress zones. Hormesis can modify the plant tolerance range to environmental factors by preconditioning and makes limits of plant tolerance to environmental factors flexible to a certain extent. In turn, as a result of tolerance range evolution, quantitative characteristics of hormesis (width and magnitude of hormetic zone) as well as the range of stimulating doses, may significantly differ in various plant species and even populations and intra-population groups, including plants at different development stages. Using hormetic preconditioning for managing plant resistance to environmental limiting factors provides an important perspective for increasing the productivity of woody plants in forestry.

Communication plays an important role in advancing scientific fields and disciplines, defining what knowledge is made accessible to the public, and guiding policymaking and regulation of public authorities for the benefit of the environment and society. Hence, what is finally published is of great importance for scientific advancement, social development, environmental and public health, and economic agendas. In recognition of these, the goal of a researcher is to communicate research findings to the scientific community and ultimately, to the public. However, this may often be challenging due to competition for publication space, although to a lesser extent nowadays that online-only publications have expanded. This editorial introduces six statistics-related issues in scientific writing that you should be aware of. These issues can lead to desk rejection or rejection following a peer review, but even if papers containing such issues are published, they may prevent cumulative science, undermine scientific advancement, mislead the public, and result in incorrect or weak policies and regulations. Therefore, addressing these issues from the early research stages can facilitate scientific advancement and prevent rejection of your paper.

Swat district is a biodiversity hub of Pakistan. The plant species, especially trees, in the Swat District are exposed to extinction threat from global climate change. Maximum entropy (MaxEnt) modelling of species distribution, using HADCM3 A2a global climate change scenario, predicted a considerable change in the future distribution of Abies pindrow (Royle ex D.Don) Royle. AUC (area under the curve) values of 0.972 and 0.983 were significant for the present and future distribution models of the species, respectively. It is clear that bioclimatic variables such as the mean temperature of the warmest quarter (bio_10) and the annual temperature range (bio_7) contribute significantly to the model and thus affect the predicted distribution and density of the species. The future model predicts that by the year 2080 population density will have decreased significantly. The highest density of the species is recorded in the eastern and western borders of the Valley in the areas of Sulatanr and Mankial. The changes in density and distribution of the species can have considerable impact, not only on the tree species itself, but on the associated subflora as well.

Các mô hình tăng trưởng và sản lượng đã được phát triển cho các cây đơn lẻ và các tổn hợp cây dựa trên 336 lô tạm thời với 405 cây phân tích thân của rừng thông Dahurian (Larix gmelinii (Rupr.) Rupr.) khắp vùng núi Đại Hưng An. Một số phương trình đã được chọn thông qua phân tích hồi quy phi tuyến. Kết quả cho thấy phương trình Richards là mô hình tốt nhất để ước tính chiều cao cây, chiều cao trung bình của tổn hợp và chiều cao thống trị của tổn hợp theo tuổi; Phương trình Power là mô hình tốt nhất để dự đoán thể tích cây dựa trên đường kính khí sinh (DBH) và chiều cao cây; Phương trình thể tích tổn hợp theo logarithmic là tốt nhất để dự đoán thể tích tổn hợp từ tuổi, chiều cao trung bình, diện tích mặt cắt ngang và các biến số khác của tổn hợp. Các mô hình này có thể được sử dụng để xây dựng bảng thể tích, bảng chỉ số vị trí và các bảng lâm nghiệp khác cho các vườn cây thông Dahurian.