Hasil untuk "Forestry"

Adi Firmanzah, Sri Mustafa, Salju Sanuddin

The purpose of this study was to determine, analyze and assess which sectors are the leading sectors in the four regions in Tana Luwu with the Location Qoutient (LQ) analysis approach. It was concluded that the economic potential of each region is different. East Luwu Regency has a base sector in mining and quarrying. North Luwu Regency has base sectors in agriculture, forestry and fisheries; electricity and gas procurement; government administration, defense and social security; and educational services. Palopo City has a base sector in electricity and gas procurement; water supply, waste management, waste and recycling; construction; wholesale and retail trade; car and motorcycle repair; transportation and warehousing; financial services; real estate; government administration, defense and social security; and health services and activities. And Luwu District has base sectors in Agriculture, Forestry and Fisheries; electricity and gas procurement; real estate;Government Administration, Defense and Social Security; health services and social activities.

Anthony H. D. Brown, M. Clegg, A. Kahler et al.

Oa Us Epa

Ojs Jki

D. M. Smith

Lingxu Zhi, Ruixin Li, Baosheng Zhang et al.

Global climate change is pushing insects into colder regions. Understanding their cold tolerance is important for predicting population dynamics. During overwintering, <i>Streltzoviella insularis</i> larvae activate the AMPK signaling pathway. This suggests that energy metabolism plays a key role under cold stress. In this study, we used enzyme activity assays, LC-MS-based targeted metabolomics, and transcriptome sequencing. We focused on six key enzymes in glycolysis and the TCA cycle. We also measured related metabolites and regulatory genes. Hexokinase (HK) and citrate synthase (CS) activities were highly sensitive to temperature. HK increased then markedly decreased; CS was significantly downregulated. Pyruvate kinase (PK), isocitrate dehydrogenase (IDH), and α-ketoglutarate dehydrogenase (KGD) showed trends that matched changes in larval cold tolerance, exhibiting an up–down–up expression trend. Glycolytic metabolites (glucose-6-phosphate, fructose-6-phosphate, 1,6-fructose-diphosphate, phosphoenolpyruvic acid) peaked at −10 °C. TCA intermediates (citrate, acetyl-CoA, α-ketoglutaric acid, and isocitrate) were more abundant at 0–4 °C. Pyruvate increased significantly. PYR content showed a significant increase followed by a decrease, peaking at 0 °C. It was converted into lactate and acetyl-CoA. ATP levels dropped and then increased, reaching their lowest level at 0 °C. These results suggest a shift from aerobic to mixed aerobic–anaerobic metabolism. Transcriptome data showed differential expression of key metabolic genes such as <i>phosphoenolpyruvate carboxykinase</i>, <i>phosphoglycerate kinase</i>, and <i>ATP synthase subunit beta</i>. These gene changes supported the trends in enzymes and metabolites. Our findings reveal a coordinated metabolic and transcriptional response to cold. This provides a basis for understanding the cold adaptation and potential range expansion of <i>S. insularis</i>.

Faisal Ismail Musa, Uttam Kumar Sahoo

Lagerstroemia speciosa (L.) Pers (Lythraceae family), called pride of India, is an important ornamental and medicinal plant having a very high demand for its fruits. Six presowing treatments, that is, hot water, cold treatment, cow dung, H2SO4, gibberellic acid (GA3), and scarification, were used to evaluate the effect of treatments on seed germination, mean germination time, and germination energy and monitor the growth performance of seedling as well as seedling quality index of L. speciosa. Among the different treatments, hot water recorded the highest germination percentage (51.95%). However, minimum mean germination time was achieved by H2SO4 treatment (21.17 days). Additionally, a significant difference (p<0.05) was observed in germination rate among treatments and the number of seeds germinated per day among treatments. The mean seedling height of L. speciosa reached a maximum height of 104 cm and a diameter of 10.67 mm in 1 year. We found a strong relation between seedling height and soil temperature (r=0.56) and between seedling characteristics and biomass parameters, while there was a negative correlation with the total percentage of water content. The Dickson quality index of the seedlings was found to be 2.68. Our findings recommend hot water as the best treatment for ensuring quality seedlings, and seedlings of 1 year is sufficiently robust for large-scale afforestation and reforestation programs.

Zhiyi Su, Wanhong Lu, Haoyang Cao et al.

Abstract Artificial hybridization remains the most effective method for genetic improvement of eucalypt, though limited research exists on the genetic basis of heterosis for interesting traits in Chinese eucalypt. We attempted to use Python in combined with SAS and SPSS to explore the relationship between parental combining ability and heterosis in controlled pollination populations of eucalypt. Our results indicated that E. urophylla had the highest general combining ability (GCA). The special combining ability (SCA) of U3423 × 3327, 06H16 × LL131, and H0733 × U6 were the highest. H0733 × U6, H0733 × P9060, and (E. urophylla × E. grandis) × 06H241 had the strongest mid-parent heterosis (MPH). U3423 × 3327, U952 × C2232, and (E. urophylla × E. grandis) × 06H241 had the strongest high-parent heterosis (HPH). We found that completely controlled by non-additive effects were (E. tereticornis × E. urophylla) × (E. urophylla), E. urophylla or (E. urophylla × E. grandis) × (open pollination). Fully controlled by additive effects were (E. tereticornis × E. urophylla) × E. camaldulensis or E. grandis, (E. urophylla) × (E. pellita × E. tereticornis), (E. urophylla × E. grandis) × E. pellita or E. tereticornis. All the findings in the present research explained the genetic basis of heterosis in eucalypt growth, and enriched the theory of hybrid breeding in eucalypt.

Fulei Wei, Xianzhi Zuo, Faxin Jin et al.

Abstract Salinity adaptation is an important issue in aquaculture. Understanding the immediate-early response to salinity stress helps in comprehending this process. In vitro experiments using cell lines can explain cell-independent reactions without the involvement of hormones in vivo. In this study, salinity stress experiments were conducted using cell line derived from the gills of Gymnocypris przewalskii (GPG cell line) to isolate immediate-early response-related genes and miRNAs using transcriptomics, followed by bioinformatics analysis. The results showed that intracellular free Ca2+ appeared to be a key factor in cell sensing and initiating downstream cell signaling in response to external salinity. Additionally, cell apoptosis was the most common feature of salinity stress, with multiple signaling pathways involved in salinity-induced cell apoptosis. Furthermore, MiRNAs played a crucial role in the rapid response to salinity stress by selectively inhibiting the expression of specific genes. Additionally, for the first time in the G. przewalskii genome, Tf2 and TY3 families of transposons were found to have responsive roles to the external salinity stress. This study contributes to a better understanding of osmotic sensing in G. przewalskii and provides theoretical assistance for improving salinity adaptation in aquaculture fish species.

Wenli Zhu, Jiannan Zhou, Guo Chen et al.

Most bamboo composites are designed referring to the specifications of wood structures. However, this approach is inadequate due to the volume difference between bamboo bundles and other fibers. Previous studies have investigated the effects of strand size of parallel strand bamboo (PSB) in tension and compression. Here, to investigate the impact of varying span-height ratio on the flexural characteristics of PSB, specimens with five different section heights were designed. Numerical simulations were performed to reveal the deformation, the failure process, and the load carrying ability of the PSB beams. The first-order anisotropic beam theory was applied to predict the internal forces. The results show that the bending property of the PSB is closely related to the section height. It is recommended that the dimension of length × width × height (300 mm × 20 mm × 30 mm) should be the most appropriate specimen size for the bending experiment. The error between the theoretical value and the test value was only about 0.4%. These endeavors can facilitate the establishment of bending test standards for bamboo structures.

Mayra del C. Fragoso-Medina, Armando Navarrete-Segueda, Eliane Ceccon et al.

Tropical rainforests offer a diverse array of real or potential forest products (FP). However, the ongoing conversion of these forests to agriculture raises concerns about the future availability and sustainability of FP. In this study, we examined the changes in availability (tree density and above-ground biomass) and species richness of native trees, recognized by local communities as sources of FP, with the forest-to-agriculture conversion in a Mesoamerican tropical rainforest region. Specifically, we tested hypotheses on whether species with FP had a higher, equal, or lower reduction in the availability, diversity, and probability of persistence than species without FP with the forest conversion. We interviewed landowners to identify tree species with FP and documented management practices and regulations for using these species. In fourteen 1 km2 landscapes, encompassing the entire range of forest-to-agriculture conversion (from 0 % to ∼100 % old-growth forest cover), we analyzed changes in the availability and richness of species with and without FP. In each landscape, we randomly established 30 plots (each 706.8 m2, totaling 420 plots and 29.7 ha sampling area) covered by old-growth forest, secondary forest, or agricultural fields (mostly cattle pastures). Over four years, we surveyed all trees with a diameter at breast height ≥ 10 cm in these plots. With the forest conversion, assemblages of tree species with FP exhibited a higher reduction in aboveground biomass than species without FP. However, assemblages of species with FP exhibited a significantly lower reduction in abundance, species richness, and a higher probability of persistence than assemblages of species without FP. Furthermore, we found evidence of implementing forest management practices favoring the preservation of species with FP in agricultural lands. Thus, we conclude that people intentionally foster the persistence of valuable species in their agricultural fields, which could have important implications for the structure and composition of future regenerating forests on abandoned agricultural lands. In the long term, this might lead to an overabundance of locally valuable species, as observed in old-growth tropical rainforests that native people ancestrally managed.

Jianghua Ye, Qi Zhang, Pengyuan Cheng et al.

Aviation mutagenesis is a fast and efficient breeding method. In this study, we analyzed the effect of aviation mutagenesis on volatile compounds and odor characteristics in Dahongpao fresh leaves and gross tea for the first time. The results showed that aviation mutagenesis significantly increased the total volatile compounds of Dahongpao fresh leaves and gross tea. Aviation mutagenesis most critically significantly increased the content of beta-myrcene in Dahongpao fresh leaves, prompting its conversion to beta-pinene, cubebol, beta-phellandrene, zingiberene, (<i>Z</i>,<i>Z</i>)-3,6-nonadienal, and 6-pentyloxan-2-one after processing, which in turn enhanced the fruity, green, spicy, and woody odor characteristics of the gross tea. This study provided a reference for further exploration of aviation mutagenic breeding of <i>Camellia sinensis</i>.

MA Hongxiu, SUN Quan, LU Haitao et al.

【Objective】 The movement of irrigation water in soil is an important parameter in irrigation design. It is affected by many factors. This paper investigates the impact of initial soil water on infiltration of subsurface irrigation water in an aeolian sandy soil. 【Method】 The outdoor experiment was conducted in tanks repacked with the sandy soil, with the initial soil water content controlled at 5.1%, 11.5%, 16.8%. The movement of the wet zone in each treatment was monitored visually. Infiltration processed was simulated by different analytical models. 【Result】 The wet zone in all treatments was approximately elliptical, with the center located at the perfusion pipe. Increasing initial soil water content accelerated the movement of the wetting front but reduced the cumulative infiltration amount and infiltration rate. The cumulative infiltration amount increased with infiltration time in a power-law function, and the infiltration index increased with the initial water content. Comparison with measured data revealed that the R2 of the Kostiakov model, Philip model, empirical model and Horton model was 0.783, 0.785, 0.923 and 0.943, respectively. When the initial water content was 5.1%, 11.5% and 16.8%, the burial depth of the irrigation pipe should not exceed 10, 20 and 30 cm, respectively, and the associated pipe spacing not exceed 30, 60 and 90 cm, respectively. 【Conclusion】 Increasing initial soil water content in aeolian sandy soil allows the irrigation pipes to be buried deeper and spaced widely. These findings are helpful for designing subsurface irrigation in aeolian sandy soil which is common in northwestern China.

Fang Liu, Zong-sheng Yuan, Zhi-hao Zeng et al.

Abstract To study the characteristics of bacterial community structure in high-yield and low-yield moso bamboo (Phyllostachys edulis) forests, we collected bamboo rhizome, rhizome root, stem, leaf, rhizosphere soil, and non-rhizosphere soil from high- and low-yield forests in Yong'an City and Jiangle County of Fujian Province, China. The genomic DNA of the samples was extracted, sequenced and analyzed. The results show that: the common differences between the high-yield and low-yield P. edulis forest samples in the two regions were mainly in bacterial community compositions in the bamboo rhizome, rhizome root, and soil samples. Differences in the bacterial community compositions in the stem and leaf samples were insignificant. The bacterial species and diversity in rhizome root and rhizosphere soil of high-yield P. edulis forests were less than those of low-yield forests. The relative abundance of Actinobacteria and Acidobacteria in rhizome root samples of high-yield forests was higher than that in low-yield forests. The relative abundance of Rhizobiales and Burkholderiales in bamboo rhizome samples in high-yield forests was higher than that in low-yield forests. The relative abundance of Bradyrhizobium in bamboo rhizome samples in high-yield forests was higher than that in low-yield forests in the two regions. The change of bacterial community composition in P. edulis stems and leaves showed little correlation with high- or low-yields of P. edulis forests. Notably, the bacterial community composition of the rhizome root system was correlated with the high yield of bamboo. This study provides a theoretical basis for using of microbes to enhance the yields of P. edulis forests.

Ana M. Leiva, Juan M. Pardo, Warren Arinaitwe et al.

Abstract Cassava witches' broom disease (CWBD) is a devastating disease of cassava in Southeast Asia (SEA), of unknown etiology. Affected plants show reduced internodal length, proliferation of leaves and weakening of stems. This results in poor germination of infected stem cuttings (i.e., planting material) and significant reductions in fresh root yields and starch content, causing economic losses for farmers and processors. Using a metagenomic approach, we identified a fungus belonging to the Ceratobasidium genus, sharing more than 98.3–99.7% nucleotide identity at the Internal Transcribed Spacer (ITS), with Ceratobasidium theobromae a pathogen causing similar symptoms in cacao. Microscopy analysis confirmed the identity of the fungus and specific designed PCR tests readily showed (1) Ceratobasidium sp. of cassava is strongly associated with CWBD symptoms, (2) the fungus is present in diseased samples collected since the first recorded CWBD outbreaks in SEA and (3) the fungus is transmissible by grafting. No phytoplasma sequences were detected in diseased plants. Current disease management efforts include adjustment of quarantine protocols and guarantee the production and distribution of Ceratobasidium-free planting material. Implications of related Ceratobasidium fungi, infecting cassava, and cacao in SEA and in other potential risk areas are discussed.

Dong-Hak Kim, Sungwon Son, Ji-Young Jung et al.

AbstractThis study characterizes the growth conditions of Cypripedium japonicum Thunb. (Korean lady’s slipper), a rare and endangered plant, across three different sites in its natural habitat. The three natural habitats of C. japonicum had different canopy densities that influenced the relative light intensity and quality (R/FR ratio) on the forest floor, the values of which, decreased with the increase in canopy density. The leaf mass per area of C. japonicum increased with an increase in canopy openness, and the difference in growth due to increased light availability was further confirmed by the chlorophyll content. Higher values of the average daily photosynthetic activity, transpiration rate, and stomatal aperture were recorded in C. japonicum growing in natural habitats that received a higher frequency of sunflecks. The activities of the photosystem and carbon fixation of the plants growing in the three habitats were compared through the light-response and A–Ci curves, and it was found that their photosynthetic capacity decreased in a low light environment. The growth and physiological characteristics of C. japonicum growing in different habitats were dependent on the light conditions in the stand, and therefore, increasing the light availability by control of canopy density may improve the propagation of C. japonicum. We believe that the findings of our study will facilitate the prediction of population dynamics and the long-term conservation and restoration of C. japonicum.

Wengang Hu, Jilei Zhang

Abstract The static lateral load–slip behavior of a single-shear plywood-to-plywood single-staple connection (SPSC) was investigated experimentally. A mechanics-based approach was used to develop mechanical models for deriving estimation equations for critical lateral loads of SPSCs based on failure modes of staple legs and connection member materials developed during static lateral loading process. Experimental results indicated that the static lateral load–slip behavior of SPSCs can be characterized with three major stages. This experiment provided the evidence that the ultimate lateral load capacity of SPSCs was partially governed by staple direct withdrawal load capacity in main members. The proposed mechanical models were verified experimentally as a valid means for deriving estimation equations for critical lateral loads of SPSCs evaluated in this study.

Joanne C. White, Margaret Penner, Murray Woods

Airborne laser scanning (ALS; LiDAR) data are an increasingly common data source for forest inventories, and approaches integrating ALS data with field plot measurements have become operational in several jurisdictions. As technology continues to evolve, different LiDAR sensors can provide new opportunities to incorporate LiDAR data into forest inventory workflows. Single photon LiDAR (SPL) enables efficient, large area data acquisition and merits further investigation for forest inventory applications. Herein, we investigated the capacity of leaf-on SPL data, combined with 269 field plots, for estimating forest inventory attributes in the Great Lakes–St. Lawrence mixedwood forests of southern Ontario, Canada. Inventory attribute estimates were validated at the stand level using independent reference data acquired for 27 intensively sampled stands. Top height, Lorey’s height, gross total volume for merchantable stems, merchantable stem volume, basal area, quadratic mean diameter, and total aboveground biomass were estimated with a relative RMSE of 13.52%, 7.24%, 14.61%, 16.27%, 14.42%, 12.25%, and 11.72%, respectively. Relative bias was < 1% for all attributes except top height (10.34%), merchantable volume (3.37%), and basal area (1.68%). Accuracy and bias varied by forest type and stand-level validation was important for assessing model performance in different stand conditions. SPL data can be used to generate accurate, area-based forest inventories in mixedwood forests that have a multitude of tree species and complex forest management histories.

Pierangelo Freschi, Simonetta Fascetti, Francesco Riga et al.

The present study was aimed to deepen the knowledge on diet and on feeding preferences of the Italian roe deer. The research was carried on in the Castelporziano Presidential Estate, a protected area of Latium coast. Quadrat method was used to assess plant frequency, whereas diet composition was determined by fecal micro-histological analysis. A total of 143 plant species were identified in the site and 109 of them were found in the feces of the <i>Capreolus capreolus italicus</i>. All over the year, most of the <i>taxa</i> were ingested in low percentages (≤5%) and the most utilized plant species were <i>Quercus suber</i>, <i>Prunus spinosa</i>, <i>Rubia peregrina</i>, and <i>Crateaegus monogyna</i>. Fagaceae and Rosaceae plant families represented the bulk of the diet and were positively selected. In addition, a positive selection on Fabaceae and Oleaceae families was found in wet season but not in dry one. In both periods the Italian roe deer showed a positive selection for deciduous woody plants and evergreen woody plants, instead avoided wild forbs and wild graminoids. Our results confirmed that this subspecies behaved as a generalist highly selective feeder.

Claude Husson

En France métropolitaine, les frênes, dans l’environnement forestier ou non, sont affaiblis depuis une dizaine d’années par une nouvelle maladie épidémique de grande ampleur appelée chalarose. Elle est causée par un champignon pathogène exotique nommé Hymenoscyphus fraxineus (forme anamorphe Chalara fraxinea) introduit en Europe et détecté pour la première fois en France en 2008 dans le nord-est de la France où les premiers flétrissements et mortalités de Frêne commun (Fraxinus excelsior) ont été signalés. L’agent pathogène s’est ensuite progressivement dispersé vers l’ouest et le sud, notamment là où le Frêne commun est bien implanté. Dans ce cas de figure, l’interaction hôte-pathogène-environnement du triangle parasitaire est optimale. Chacun de ces trois éléments est décrit ici pour comprendre comment la chalarose est devenue en France une maladie émergente causée par un pathogène invasif.