Hasil untuk "Forestry"

A. Meharg

Jonathan D. Burnett, Kristin L. Jaeger, Sherri L. Johnson et al.

Abstract Accurate mapping of headwater streams and their flow status has important implications for understanding and managing water resources and land uses. However, accurate information is rare, especially in rugged, forested terrain. We developed a streamflow permanence classification model for forested lands in western Oregon using the latest light detection and ranging‐derived hydrography published in the National Hydrography Dataset. Models were trained using 2,518 flow/no flow field observations collected in late summer 2019–2021 across headwaters of 129 sub‐watersheds. The final model, the Western Oregon WeT DRy model, used Random Forest and 13 environmental covariates for classifying every 5‐m stream sub‐reach across 426 sub‐watersheds. The most important covariates were annual precipitation and drainage area. Model output included probabilities of late summer surface flow presence and were subsequently categorized into three streamflow permanence classes—Wet, Dry, and Ambiguous. Ambiguous denoted model probabilities and associated prediction intervals that extended over the 50% classification threshold between wet and dry. Model accuracy was 0.83 for sub‐watersheds that contained training data and decreased to 0.67 for sub‐watersheds that did not have observations of late summer surface flow. The model identified where predictions extrapolated beyond the domain characterized by the training data. The combination of spatially continuous estimates of late summer streamflow status along with uncertainty and extrapolation estimates provide critical information for strategic project planning and designing additional field data collection.

Zhen Liu, Jing Li, Ruixing Hou et al.

Soil salinisation has been considered a substantial ecosystem issue with negative effects on sustainable agricultural practices. Practices of vegetation restoration are widely conducted for coping with saline soil degradation, especially in saline-alkali abandoned farmland. Compared with bulk soils, the rhizosphere soils of plants have different microbial community structures. However, how associations and functions of microbes vary in the rhizosphere and bulk soils of salt-tolerant plants remains unclear, limiting the successful implementation and efficacy of vegetation in restoring saline-alkali lands. Here, we analysed the fungal community composition, functional guilds, and co-occurrence networks in both rhizosphere and bulk soils of typical plant species in the abandoned farmland of the Yellow River Delta, China. Not all plant species had significantly different fungal community compositions and relative functional guild abundances between the rhizosphere and bulk soil. Soil nutrient concentrations explained more variance in the soil fungal community. Network analyses indicated that the rhizosphere fungal network had more nodes and links, more negative links, and higher modularity; however, fewer species were involved in the meta-module than those in the bulk soil network, indicating a more complex topology and niche differentiation therein. More generalist species and indicator taxa essential for carbon and nitrogen cycling (e.g., Sordariomycetes and Dothideomycetes) were identified in the salt-tolerant plant rhizosphere network. Overall, the salt-tolerant plants’ rhizosphere had a more stable fungal co-occurrence network and recruited more keystone species compared to the bulk soil, which could benefit soil nutrient cycling and soil restoration in abandoned farmlands.

Emilija Beniušytė, Ieva Čėsnienė, Vaida Sirgedaitė-Šėžienė et al.

Due to temperature changes, forests are expected to encounter more stress than before, both in terms of biotic factors, such as increased insect attacks, and abiotic factors, such as more frequent droughts. Priming trees to respond to these changes faster and more effectively would be beneficial. Induced systemic resistance (ISR) is a mechanism that is turned on when plants encounter unfavorable conditions. Certain elicitors, such as jasmonic acid (JA) are known to induce plants’ metabolic response. However, even though studies on ISR in herbaceous species are common and varied ISR elicitors can be used in agriculture, the same cannot be said about trees and forestry enterprises. We aimed to investigate whether JA used in different concentrations could induce metabolic changes (total phenol content, total flavonoid content, photosynthesis pigment content, antioxidant enzyme activity) in <i>Pinus sylvestris</i> seedlings and how this varies between different pine half-sib families (genotypes). After six weeks with a single application of JA, pine seedlings in several pine genetic families exhibited increased antioxidant enzyme activity, total phenol content and carotenoid content that correlated positively with JA concentrations used. Results from other genetic families were varied, but in many cases, there was a significant response to JA, with a noticeable increase as compared to the unaffected group. The impact on chlorophyll content and flavonoids was less noticeable overall. A positive effect on seedling growth parameters was not observed in any of the test cases. We conclude that JA can induce systemic resistance after a single application exogenously in <i>P. sylvestris</i> seedlings and recommend that the use of JA needs to be optimized by selecting appropriate concentrations.

Mustamu N E, Tampubolon K, Alridiwirsah et al.

Adaptation test of local maize plants under drought stress requires early selection at the seedlings stage through Poly Ethylene Glycol (PEG-6000). This study aimed to identify local varieties of maize plants from North Sumatra under drought stress with several doses of PEG-6000. This study was conducted from July to November 2022 using a completely randomized design with two factors and three replications. The sixteen local maize (L) and a hybrid variety (H) of maize as a comparison were used as the first factor. The PEG doses were 0; 100; 200; 300; 400; and 500 g L-1 as the second factor. Data were analyzed using analysis of variance and duncan's multiple range test at P<0.05. The results showed that the LSB5 and LSB4 of local maize from Serdang Bedagai had the greatest number of seeds germinated and water content of seedlings at 40.17 seeds and 74.43%, respectively. The higher PEG dose of 500 g L-1 inhibited the number of seeds germinated and water content of local maize seedlings to 32.27 and 11.45%, respectively. The interaction of local varieties with PEG doses were insignificant effects on both characteristics of local maize.

Yu Wu, Yu Wu, Wen Hui Huang et al.

IntroductionTilia miqueliana is an endemic species whose population is declining. The permeability barrier and mechanical constraint of the pericarp (seed coat) are important causes of its seed dormancy. Although there has been considerable research on this subject, questions remain regarding how the permeability barrier and mechanical constraint of the seed coat are eliminated during dormancy release and how water enters the seed. Therefore, protecting the species by improving its germination/dormancy breaking in the laboratory is urgentMethodsIn this study, the changes in the cellular structure, mechanical properties, and components of the Tilia miqueliana seed coat after an H2SO4-gibberellic acid (GA3) treatment were analyzed during dormancy release. Various analyses (e.g., magnetic resonance imaging, scanning electron microscopy, and paraffin section detection) revealed the water gap and water channel.ResultsThe H2SO4 treatment eliminated the blockage at the micropyle and hilum of the seeds. Water entered the seeds through the water gap (micropyle) rather than through the hilum or seed coat, after which it dispersed along the radicle, hypocotyl, and cotyledon to the endosperm. During the cold stratification period, the cellular structure was damaged and an increasing number of holes appeared on the inner and outer surfaces of the seed coat. Vickers hardness tests showed that GA3 decreased the seed coat hardness. Additionally, the seed coat lignin and total phenol contents continuously decreased during the cold stratification period. Notably, the Liquid chromatography–mass spectrometry (LC–MS) analysis of the seed coat detected polyethylene glycol (osmoregulator), which may have destabilized the water potential balance inside and outside the seed and increased the water content to levels required for germination, ultimately accelerating seed dormancy release.DiscussionThis sophisticated and multi-level study reveals how H2SO4 and GA3 eliminate the permeability barrier and mechanical constraints of the seed coat during dormancy release of Tilia miqueliana seeds. This will be beneficial to artificially assist the natural regeneration and population expansion of Tilia miqueliana.

Kaimeng Ding, Shiping Chen, Jiming Yu et al.

Aiming at the deficiency that blockchain technology is too sensitive to the binary-level changes of high resolution remote sensing (HRRS) images, we propose a new subject-sensitive hashing algorithm specially for HRRS image blockchains. To implement this subject-sensitive hashing algorithm, we designed and implemented a deep neural network model MultiRes-RCF (richer convolutional features) for extracting features from HRRS images. A MultiRes-RCF network is an improved RCF network that borrows the MultiRes mechanism of MultiResU-Net. The subject-sensitive hashing algorithm based on MultiRes-RCF can detect the subtle tampering of HRRS images while maintaining robustness to operations that do not change the content of the HRRS images. Experimental results show that our MultiRes-RCF-based subject-sensitive hashing algorithm has better tamper sensitivity than the existing deep learning models such as RCF, AAU-net, and Attention U-net, meeting the needs of HRRS image blockchains.

M Masihpoor, A.A. Darvishsefat, R. Rahmani et al.

Climate change and human interventions as a whole have had negative and remarkable effects on the quantity and quality of forests. Beside the change in the forests extent, which has always been considered and monitored, its phenological changes have also been investigated in the last decade. The NDVI Vegetation Index derived from satellite data is an appropriate proxy for quantifying and expressing forest status including phenological changes. This study aimed to characterize the trend of start, end, and length of growing season using NDVI satellite time series dataset over 18-year time periods and then assess their relationship with precipitation and temperature parameters. This study was carried out over the southern Zagros forests using MODIS-NDVI time series with temporal and spatial resolution of 16-day and 250 meters, respectively. The precipitation and temperature datasets were also collected from regional synoptic meteorological stations. After preprocessing steps, 414 NDVI images during 2000-2017 were analyzed pixel by pixel to extract the start, end, and length of the growing season using Midpoint method, considering 50% and 35% thresholds of NDVI annual amplitude for start and end of the growing season, respectively. Then, the statistical significance of phenological metrics was assessed. Based on the results, the mean dates for the start and the end of growing season were 16th March and 15th August, respectively, with the mean length of growing season of 151 days in the study period from 2000 to 2017. Considering 35% of NDVI annual amplitude for the end of growing season, the mean date for the end of growing season was 8th September and the mean length of growing season was 190 days. The seasonal trend showed that the start and the end of growing season has occurred respectively 0.02 and 1.04 days earlier per year in the southern Zagros forests during 2000-2017. The length of growing season has been shortened 1.02 day per year. However, variation in the start and the end dates and the length of growing season have not been significant in 93%, 81% and 81% of the region, respectively, at 90 % confident level. Generally, the change in the occurrence of the end of growing season was greater than the start of growing season. A weak correlation was observed between phenological changes and climate parameters like temperature and precipitation in the study area.

Yiqun Ji, Zhendong Yan, Chaojun Tang et al.

Research on the classical analogy of asymmetric Fano resonances has gained momentum in recent years, owing to the steep dispersion of the Fano-like profile in classical systems, such as plasmonic nanostructures and metamaterials, which has numerous applications. We studied the double Fano-like resonances arising in a waveguide structure made of a periodic array of gold nanospheres placed on the top surface of an indium tin oxide (ITO) film, which is deposited on a silica substrate. These resonances emanate from the interference coupling between the dipolar surface plasmon mode of the individual gold nanospheres and the zero-order transverse electric (TE) and transverse magnetic (TM) waveguide modes within the ITO film. Increasing the array period of the gold nanospheres or thickness of the ITO film shifted the resonance peaks towards the low-frequency side corresponding to the excitation frequencies of the zero-order TE and TM waveguide modes, which were red-shifted. Additionally, the double Fano-like resonance profiles were approximated using an analytical Fano interference model.

مازیار حیدری, مهدی پورهاشمی

سابقه و هدف: محصولات غیرالواری جنگل شامل کالاهای غیر از چوب با منشاء بیولوژیکی از جنگل‌ها، درختزارها و درختان خارج از محدوده جنگل است. بنه یکی از درختان ارزشمند جنگل‌های زاگرس از نظر اکولوژیکی و اقتصادی است که محصولات غیرالواری متعددی از این درختان برداشت می شود. در شهرستان بانه استان کردستان، جوامع محلی از درخت بنه استفاده‌های مختلفی می‌کنند و دانش سنتی قابل‌توجهی در این زمینه دارند که کمتر به آن‌ها پرداخته شده‌است. با توجه به درختان بنه در شهرستان بانه و تنوع محصولات غیرالواری این درختان، هدف این پژوهش شناسایی و معرفی محصولات الواری و غیرالواری مربوط به این گونه در بخش نمشیر (روستاهای زیویه و بیلو) شهرستان بانه در استان کردستان بود.مواد و روش ها: جهت گردآوری اطلاعات بهره برداری‌های محصولات غیرالواری درختان بنه، از مصاحبه‌های ساختارنیافته و نیمه‌ساختاریافته و مشاهده مستقیم استفاده شد. از روش نمونه‌برداری گلوله‌برفی (Snowball sampling) برای مصاحبه‌های نیمه‌ساختاریافته با افراد کلیدی استفاده شد. در این پژوهش، 60 اطلاع‌رسان از سامان‌های عرفی مورد پژوهش انتخاب شدند و در قالب 28 مصاحبه با متوسط یک ساعت و 10 دقیقه (برای هر مصاحبه) داده‌ها جمع‌آوری شد. یافته‌ها: نتایج نشان داد که بنه در سامان عرفی روستاهای بیلو و زیویه به ترتیب 1/4 و 8/8 درصد از ترکیب گونه‌ای درختی را شامل شده و سهمی معادل 09/2 و 56/2 درصد در اقتصاد خانوار دارد (درآمد خالص خانوار در دو روستای فوق به ترتیب 07/34 و 12/41 میلین تومان در سال است). در هر دو روستا به طور متوسط 19/4 میلیون تومان درآمد از طریق منابع طبیعی حاصل می شود و میانگین درآمد حاصل از هر درخت بنه در روستای زیویه (یا 8/109 هزارتومان) بیشتر از روستای بیلو (با 5/96 هزار تومان در سال) است. محصولات الواری و غیرالواری درختان بنه در دسته‌های شامل کاربرد دارویی ( برداشت شیره بنه و عرق بنه)، غذایی (استفاده از میوه بنه برای معطر سازی دوغ، تهیه خوراک (آش)، ترشی بن، روغن بنه و عرق بنه، معجون گوژمه)، صنایع دستی (تولید تسبیح و تخته نرد)، انرژی (تولید ذغال و چوب سوختی)، ساختمانی (بکار گیری در ساختمان سازی) و دامداری (استفاده از برگ در تعلیف دام‌های کوچک (بره‌ها) تقسیم‌بندی شدند. برداشت شیره بنه با 8/62 درصد سهم از کل برداشت‌ها به‌عنوان مهم‌ترین برداشت سنتی از درختان بنه شناسایی شد و پس از آن استفاده از میوه درختان بنه با 33 درصد سهم در درجه بعدی قرار دارد. از طرفی 3/33 و 3/8 درصد از محصولات درخت بنه در بازارهای استانی و بین المللی راه می یابد و و باقی برداشت‌های سنتی مصرف خانوار در شهرستان بانه دارند. عمده بهره‌برداری‌ غیراصولی شیره بنه شامل برداشت‌های سالانه، تیغ‌زنی و کاسه‌گیری غیرمتناسب با توان درختان بنه، برداشت سقز از درختان مسن و تنه‌تهی و استفاده از کاسه‌های پلاستیکی هستند.نتیجه گیری: درمجموع، نتایج این پژوهش مؤید وجود دانش‌های سنتی متعددی در ارتباط با درخت بنه بود، اما تأکید می‌شود که این دانش‌ها باید با اصول مدیریت پایدار جنگل سازگار شوند. برای کاهش اثرات منفی برداشت شیره بنه از درختان بنه راهکارهایی همانند افزایش دوره بهره‌برداری به پنج سال، عدم سقزگیری از درختان مسن و سرخشکیده، عدم استفاده از کاسه‌های پلاستیکی پیشنهاد شد.

Rima D. Lucardi, Lisa E. Wallace, Gary N. Ervin

The spatial expansions of invasive organisms in the novel range are generally expected to follow an isolation-by-distance relationship (IBD) if the invasion is biologically driven; however, many invasions are facilitated anthropogenically. This research focused on the extant expansion patterns of cogongrass (<i>Imperata cylindrica</i>). Cogongrass is a widespread invasive species throughout the southern United States (US). Patterns of infestation vary among US states. Cogongrass is pyrogenic, and its invasion threatens softwood (<i>Pinus</i> spp.) plantations, a substantial economic market for this US region. Over 600 individuals were sampled from seven invaded US states, using amplified fragment length polymorphisms (AFLPs) to assess genetic diversity and population structure. We suspected that differences in historical management efforts among US states influenced differences in genetic diversity and structure. We detected two genetic lineages at the highest level of analysis. One genetic lineage was locally restricted, whereas the other was found throughout the study region. Admixed individuals were found in all US states and consistently co-occurred with the dominant lineage, suggesting that secondary contact and hybridization may have facilitated expansion. The widespread prevalence of only one of the two detected genetic lineages suggests a primary genetic lineage responsible for on-going population expansion in the US.

Alexandra C. Morel, Alexandra C. Morel, Mark Hirons et al.

Cocoa yields in Ghana remain low. This has variously been attributed to low rates of fertilizer application, pollinator limitation, and particularly dry growing conditions. In this paper we use an African forest-agriculture landscape dominated by cocoa (Theobroma cacao) to develop an ecological production function, allowing us to identify key ecological and management limits acting on cocoa yields simultaneously. These included more consistent application of fertilizers inter-annually, distributing rotting biomass throughout the farm and reducing the incidence of capsid attacks. By relaxing these limits, we estimate plausible increases in yields and, by extension, farm incomes. Our analysis reveals that resulting increases in cocoa yields requiring both ecological and intensive management interventions could be significant (113 ± 60%); however, benefits are disproportionately realized by the wealthiest households. We found that wealthier households benefited proportionally more from ecological intensification methods (e.g., leaving more rotting biomass in their farms) and the poorest households benefited proportionally more from capital-intensive intensification methods (e.g., pesticide and fertilizer applications). We treated poverty as multi-dimensional, and show that only certain dimensions of poverty (school attendance, assets, and food security) are significantly related to cocoa incomes, while several other dimensions (access to clean water, sanitation and electricity, and infant mortality) are not. We explore how increased household cocoa incomes could impact different dimensions of poverty. Our findings suggest, that if all households adopted the optimal level of each of these management options, and in so doing had similar poverty profiles to those households already managing optimally, we would see the community-averaged probability: a child of a household misses school decrease from 47 to 31%, a household would be able to acquire assets increase from 40 to 59% and a household would have access to an adequate amount of food increase from 62 to 79%.

Jishan Fan, Bessem Samet, Yong Zhou

In this paper, we first establish a regularity criterion for the strong solutions to the density-dependent incompressible MHD system with zero resistivity in a bounded domain. Then we use it and the bootstrap argument to prove the global well-posedness provided that the initial data u0 and b0 satisfy that (d-2)||∇u0 || L2+||b0||w1,p are sufficiently small with . We do not assume the positivity of initial density, it may vanish in an open subset (vacuum) of Ω.

Vida Stravinskienė, Edmundas Bartkevičius, Jolita Abraitienė et al.

Trees are often grown alongside roads in urban areas for their aesthetic and ecological values but are exposed to an array of natural and man-made stresses that impact on their overall health. The aim of this study was to determine the health of Scots pine (Pinus sylvestris L.) trees growing in urban forests alongside the Vilnius–Kaunas–Klaipėda highway in Lithuania. Long-term monitoring was conducted between 1998 and 2014, when health indicators were evaluated in 714 trees at different distances from the highway. The decrease of crown defoliation, amount of dead branches and foliage discolouration at all distances from the roadbed was detected. The results showed that trees furthest (450–500 m) from the roadbed were in better health than those growing close to the highway, exhibiting lowest crown defoliation (25.8 ± 1.6% in 1998, 12.3 ± 1.6% in 2014) compared with trees growing close to highway (47.2 ± 1.6% in 1998; 25.1 ± 1.7% in 2014), lowest foliage discolouration (14.8 ± 1.2% in 1998, 9.8 ± 0.8% in 2014), a lower amount of dead branches (14.8% ± 1.2% in 1998, 9.8% ± 0.8% in 2014) and a longer needle retention (3.2 ± 0.03 years in 2014 comparing with to 1.9 ± 0.02 close to the highway). The condition of the tree tops was good throughout the study period, with 77% of assessed trees being healthy. Statistically significant improvement in tree health was observed between 1998 and 2014, indicating an improvement in the overall health of the environment. Keywords: Urban forests, Highway edges, Pinus sylvestris L., Condition, Health indicators

Bruña-García X, Marey-Pérez Manuel F

Stakeholder participation in decisions related to forest planning is essential to get long-lasting and viable solutions. Nowadays, public participation is necessary to reach consensus in natural resource management and in citizen governance of land. It is a key element in a forest planning on a strategic level. However, only the first steps are being taken to include public participation in forest planning within the forestry sector. This paper proposes a review of public participation processes in forest planning as a reference for the development of new methodologies in areas with no previous experience in participative processes. The assessment of the existing scientific literature and its use in different models and countries show a high diversity of responses to the challenge of including social aspects and integrating them with methodological proposals.

Steven P. Brady

Despite theoretical understanding and empirical detection of local adaptation in natural environments, our knowledge of such divergence in fragmented habitats remains limited, especially in the context of microgeographic spatial scales and contemporary time scales. I used a combination of reciprocal transplant and common garden exposure experiments to evaluate potential microgeographic divergence in a pool-breeding amphibian occupying a landscape fragmented by roads. As indicated by reduced rates of survival and increased rates of malformation, I found evidence for maladaptation in road adjacent populations. This response is in direct counterpoint to recently described local adaption by a cohabiting species of amphibian. These results suggest that while divergence might commonly follow habitat modification, the direction of its outcome cannot be generalized even in identical habitats. Further, maladaptive responses can be associated with a more generalized depression effect that transcends the local environment. Alongside recent reports, these results suggest that maladaptive responses may be an emerging consequence of human-induced environmental change. Thus future studies should carefully consider the population unit as a key level for inference.

L. Fortmann, James William Bruce

G. Waller

Mikko Vastaranta

A. Heinemeyer, M. Wilkinson, R. Vargas et al.

Quantifying soil organic carbon stocks (SOC) and their dynamics accurately is crucial for better predictions of climate change feedbacks within the atmosphere-vegetation-soil system. However, the components, environmental responses and controls of the soil CO₂ efflux (<i>R</i>_s) are still unclear and limited by field data availability. The objectives of this study were (1) to quantify the contribution of the various <i>R</i>_s components, specifically its mycorrhizal component, (2) to determine their temporal variability, and (3) to establish their environmental responses and dependence on gross primary productivity (GPP). In a temperate deciduous oak forest in south east England hourly soil and ecosystem CO₂ fluxes over four years were measured using automated soil chambers and eddy covariance techniques. Mesh-bag and steel collar soil chamber treatments prevented root or both root and mycorrhizal hyphal in-growth, respectively, to allow separation of heterotrophic (<i>R</i>_h) and autotrophic (<i>R</i>_a) soil CO₂ fluxes and the <i>R</i>_a components, roots (<i>R</i>_r) and mycorrhizal hyphae (<i>R</i>_m). <br><br> Annual cumulative <i>R</i>_s values were very similar between years (740 &plusmn; 43 g C m⁻² yr^&minus;1) with an average flux of 2.0 &plusmn; 0.3 μmol CO₂ m⁻² s⁻¹, but <i>R</i>_s components varied. On average, annual <i>R</i>_r, <i>R</i>_m and <i>R</i>_h fluxes contributed 38, 18 and 44%, respectively, showing a large <i>R</i>_a contribution (56%) with a considerable <i>R</i>_m component varying seasonally. Soil temperature largely explained the daily variation of <i>R</i>_s (<i>R</i>² = 0.81), mostly because of strong responses by <i>R</i>_h (<i>R</i>² = 0.65) and less so for <i>R</i>_r (<i>R</i>² = 0.41) and <i>R</i>_m (<i>R</i>² = 0.18). Time series analysis revealed strong daily periodicities for <i>R</i>_s and <i>R</i>_r, whilst <i>R</i>_m was dominated by seasonal (~150 days), and <i>R</i>_h by annual periodicities. Wavelet coherence analysis revealed that <i>R</i>_r and <i>R</i>_m were related to short-term (daily) GPP changes, but for <i>R</i>_m there was a strong relationship with GPP over much longer (weekly to monthly) periods and notably during periods of low <i>R</i>_r. The need to include individual <i>R</i>_s components in C flux models is discussed, in particular, the need to represent the linkage between GPP and <i>R</i>_a components, in addition to temperature responses for each component. The potential consequences of these findings for understanding the limitations for long-term forest C sequestration are highlighted, as GPP via root-derived C including <i>R</i>_m seems to function as a C "overflow tap", with implications on the turnover of SOC.