Main Principles and Methods of Identification of High Conservation Value Forests in the Conditions of Mountainous Relief： Case of Armenia

Armenia is a small mountainous country with remarkable biodiversity. The forest cover of Armenia makes up 11.17% of the total territory of Armenia. The forests of Armenia make important habitat for numerous biological objects. They also provide important ecosystem services, including key services to forest adjacent population. Deforestation and forest degradation are serious threats in Armenia. In the result of special studies the principles and criteria for identification of HCVFs （high conservation value forests） in the conditions of Armenia were developed. They are based on the guidelines for identification and management of HCVFs, but adapted to the conditions of mountainous forests of Armenia as a small country. Out of six generic types of HCVFs, it is suggested to define five types of HCVFs with respective sub-types. Proper protection of such forests shall ensure conservation of biological diversity and maintenance of ecosystem services provided by forests.

Analysis of Fragmentation Processes in High-Mountain Forests of the Centre of Mexico

High-mountain forests (>3500 masl) are the main supplier of environmental services to Mexico City and its metropolitan area. Taking as a study case the Nevado de Toluca National Park, this article focuses on the considerable reduction on the density of its forest cover, characterised by disturbances in the structure and dynamics of Pinus hartwegii. This specie is located towards the upper limits of the altitudinal gradient (3500 - 4100 masl) constituting the only pine species in the world capable to be established in those extreme environmental conditions. The information was collected through the implementation of 30 Sampling Plots (SP) of 20 × 50 mts (1000 m2) in three forest density categories: dense, semi-dense and fragmented. For each forest category, all trees ≥2.5 cm DBH were measured in 10 SPs. The measurement variables were DBH, total and commercial height, forest health and forest extraction. The results show the abundance of dense, semi-dense and fragmented forest (336, 202 and 150 trees/Ha-1), with extraction percentages of 11%, 20% and 33% respectively. The horizontal structure distribution shows the shape of an inverted J for the three conditions. However, the phytosanitary conditions of the semi-dense forests (83% infested trees) and fragmented (63% infested trees), do not guaranties the survival of the adult trees, implying an intensification of the fragmentation process for the next decade;given the reduction of the regeneration patterns due to the lack of healthy tree breeding.

Comparative Research on Zoning of High Conservation Value Forest and Ecological Forest

High conservation value forest(HCVF) theory has aroused wide concerns among related forestry sectors in China,but the zoning and identification of HCVF only have been implemented in a few forest management units(FMUs). As there is no quantitative indicator for identifying and zoning HCVF in China,most FMUs are unable to have an exact zoning result. This paper introduced the concepts of HCVF and ecological forest,and compared their similarities and differences in terms of identification criteria,zoning methods and application scope. With four Chinese FMUs as case studies,some suggestions were proposed for establishing a zoning scheme of HCVF so as to promote the development of HCVF in China.

Analysis of forest structural complexity using airborne LiDAR data and aerial photography in a mixed conifer–broadleaf forest in northern Japan

Determining forest structural complexity,i.e.,a measure of the number of different attributes of a forest and the relative abundance of each attribute,is important for forest management and conservation.In this study,we examined the structural complexity of mixed conifer–broadleaf forests by integrating multiple forest structural attributes derived from airborne Li DAR data and aerial photography.We sampled 76 plots from an unmanaged mixed conifer–broadleaf forest reserve in northern Japan.Plot-level metrics were computed for all plots using both field and remote sensing data to assess their ability to capture the vertical and horizontal variations of forest structure.A multivariate set of forest structural attributes that included three Li DAR metrics(95 th percentile canopy height,canopy density and surface area ratio) and one image metric(proportion of broadleaf cover),was used to classify forest structure into structural complexity classes.Our results revealed significant correlation between field and remote sensing metrics,indicating that these two sets of measurements captured similar patterns of structure in mixed conifer–broadleaf forests.Further,cluster analysis identified six forest structural complexity classes includingtwo low-complexity classes and four high-complexity classes that were distributed in different elevation ranges.In this study,we could reliably analyze the structural complexity of mixed conifer–broadleaf forests using a simple and easy to calculate set of forest structural attributes derived from airborne Li DAR data and high-resolution aerial photography.This study provides a good example of the use of airborne Li DAR data sets for wider purposes in forest ecology as well as in forest management.

Carbon sequestration capability of Fagus sylvatica forests developing in the Majella National Park (Central Apennines,Italy)

Terrestrial ecosystems represent a major sink for atmospheric carbon(C) and temperate forests play an important role in global C cycling, contributing to lower atmospheric carbon dioxide(CO2) concentration through photosynthesis. The Intergovernmental Panel of Climate Change highlights that the forestry sector has great potential to decrease atmospheric CO2concentration compared to other sectoral mitigation activities. The aim of this study was to evaluate CO2sequestration(CO2S)capability of Fag us sylvatica(beech) growing in the Orfento Valley within Majella National Park(Abruzzo,Italy). We compared F. sylvatica areas subjected to thinning(one high-forest and one coppice) and no-management areas(two high-forests and two coppices). The results show a mean CO2S of 44.3 ± 2.6 Mg CO2ha-1a-1,corresponding to 12.1 ± 0.7 Mg C ha-1a-1the no-managed areas having a 28% higher value than the managed areas. The results highlight that thinning that allows seed regeneration can support traditional management practices such as civic use in some areas while no management should be carried out in the reserve in order to give priority to the objective of conservation and naturalistic improvement of the forest heritage.

Effects of single-tree selection harvesting on hymenopteran and saproxylic insect assemblages in the canopy and understory of northern temperate forests

Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels （selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies） between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels （order, family and subfamily）. Similarly, richness and abundance at the lowest-taxon level （braconid morphospecies） were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance （for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies） and richness （for braconid morphospecies） in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.

Mapping Glitches of Juniper Forests in Lebanon under Natural Conditions and Anthropogenic Activities

In 1965, the first forest map of Lebanon was produced. It is the oldest spatial distribution representation of junipers. Landcover maps of 2002 and 2010 are the most detailed spatial distribution that spatially shows forests. Juniper forests are found in Lebanon as mainly as clear to low density coverage. High-density juniper forests are rarely found and only on Mount-Lebanon. Juniper forests are also mixed with oaks on the Eastern flank of Mount-Lebanon. Mapping juniper forests have demonstrated high degree of complexity, especially because of their low density and being mixed. The spatial representation of juniper forests was compared between the 1965 forest map and the landcover maps of 2002 and 2010. GIS environment was used to extract juniper forests from all maps. The degree of matching between juniper forests was investigated regarding the total area and spatial overlapping. Juniper forests were examined to their spatial locations, comparing the three maps. Spatial changes and anthropogenic effect were obtained, using Google Earth facilities. Google earth had satellite images acquired since 2014. Landcover maps of 2002 and 2010 have spatially matched forest map of 1965 by about 90% and 50% respectively. Spatial coverage of juniper forests were about 12,000, 26,000 and 28,000 ha on the 1965 forest map, landcover maps of 2003 and 2010 respectively. Anti-Lebanon juniper forests were not well represented on both landcover maps. Anthropogenic activities were mainly agriculture that affected juniper forests. Cultivations have replaced about 2% of the spatial coverage of 1965 Juniper forests. Quarries and urban existed inside juniper forests but in very limited areas. Juniper forests delineation did not completely match neither between the available maps, nor to the ground. Some juniper forests were not spatially represented on all maps or existing maps represented only portion of juniper forests. Juniper forest mapping requires more consideration and field investigation. High spatial resolution satellite images are among the solutions but delimiting juniper would require extensive fieldwork and specific remote sensing treatments. Being centuries old forests and characterized by High Mountain elevations, these important conifer forests are needed to be mapped with higher accuracy for better statistics and conservation.

Dominant Factors of the Nature Regulating CO2 Release from Boreal Forest Land

Temperature is often considered as a primary factor for microbial decomposition of soil organic carbon. Boreal forests are the large terrestrial carbon pool: if carbon stored in this region is transferred to the atmosphere as CO2 by a warming-induced acceleration of its decomposition, there will be positive feedback to global warming. It is reported that real issue regarding the release of carbon from soils to the atmosphere is how natural factors interact to influence decomposition of soil organic matter, so we observed mass losses (indicating decomposition rates) from litter and litterfall in a Northern Fennoscandia forest over 3 years under natural conditions. Our field survey has demonstrated that mass losses from most kinds of sample had moderate correlation with the temperature. Of the various samples, the canopy-gap litter alone had a greater rate (~70%) of mass loss. It is at least necessary to make a clear distinction of monitoring sites (under the canopy and in the canopy gap) when discussing the effect of climate on soil CO2 release from high-latitude forests. Though temperature, soil moisture and soil properties are prioritized in the issue of soil CO2 release, our results suggest that the fungi/bacteria rate and the wind-related mix/fragmentation are also important factors to be considered;however, this speculation is just tentative, and more detail research is called for.

高氮负荷森林生态系统对大气氮沉降降低的响应研究进展

大气氮沉降对全球生物多样性和生态系统功能构成严重威胁。过去50多年,由于减排措施的实施,欧美国家率先出现大面积区域的氮沉降降低,中国从2010年开始趋于稳定,氮沉降的未来变化趋势可能因全球各地而异。本研究采用文献检索方法和综合分析方法,综述了国内外氮沉降恢复的方法,分析了森林生态系统土壤(酸化和溶液化学)、结构(植被-微生物多样性)与功能(生产力和碳吸存)对氮沉降降低的响应。随着氮沉降的降低,植被物种组成、土壤微生物群落和土壤过程可能恢复缓慢,而一些土壤参数(如pH、硝酸盐和铵浓度等)对氮输入减少的响应相对较快。当氮沉降降低时,可在某种程度上减轻土壤酸化,促进树木生长,但也可能因环境氮沉降速率依然很高并保持土壤酸化,林木的活力仍在恶化。植被多样性的恢复可能存在恢复障碍并在短期内难以维持富营养化的恢复,但促进了贫营养型物种的增加。森林生态系统恢复响应对减排政策存在延迟,且氮沉降增加存在遗留效应,致恢复相当缓慢,但恢复只是时间问题。因此,高氮负荷生态系统的恢复是一个长期缓慢的过程,进一步加强减排尤为重要。

Response of saproxylic insect communities to logging history, tree species, stage of decay, and wood posture in the central Nearctic boreal forest

Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest management.We used a split-plot ANOVA design to analyze differences in selected saproxylic insects（all arthropod orders and dipteran and parasitic hymenopteran families） emerging from dead wood of sites with different logging histories（horse-logged,mechanically-logged and unlogged）,tree species（Populus and Picea）,stage of decay（early-and late-decay stages） and posture（standing and downed logs） in the boreal forest of central Canada.No clear effects of logging history were seen for the studied taxa; however,interaction between logging history and other dead wood features was apparent.Cecidomyiidae consistently emerged more from Populus than from Picea dead wood.Most of the studied saproxylic families were more abundant in late-decay than in early-decay wood.Dipterans of the Cecidomyiidae,Ceratopogonidae,Empididae,Mycetophilidae and Sciaridae families,and hymenopterans of the Diapriidae and Ichneumonidae families were significantly more abundant in downed than in standing dead wood.In contrast,Mymaridae was most abundant in standing dead wood.Our study provides evidence that some insects at high taxonomic levels respond differently to dead wood quality,and this could inform future management strategies in the boreal forest for the conservation of saproxylic fauna and their ecological functions.

乡村振兴背景下森林康养特色旅游高质量发展探讨

乡村振兴战略,其根本在于推进乡村产业发展,森林康养特色资源的挖掘,为解决乡村发展难题提供了有效路径。作为新型旅游业态,森林康养品牌的打造,要坚持高质量发展规划,将产业资源整合、保护与开发衔接起来,挖掘地方资源禀赋,优化完善相关配套设施,重视现代康养医疗技术与旅游产业链的跨界发展,促进森林康养产业成为推动乡村经济转型升级的新的增长点。

落实习近平总书记建设森林城市指示 推进城市绿化事业高质量发展

建设森林城市是我国推进城市生态系统修复和改善人居环境的重要手段,是习近平总书记亲自指导推动的一项生态事业,取得了巨大成效,是经过实践证明符合中国国情的城市生态建设之路,需要久久为功的坚持下去。在我国进入建设人与自然和谐共生现代化和美丽中国的时代背景下,继续贯彻落实习近平总书记建设森林城市指示要求,保持建设森林城市的战略定力,对推进城市绿化事业高质量发展至关重要。本文从历史维度系统梳理了习近平总书记为森林城市建设定方向、明思路、促推广和提质量的发展脉络及精神实质;从北京维度围绕习近平总书记对北京森林城市建设提出的科学育林、延续乡愁、提升颜值和覆盖全域的新要求,阐述了其深刻内涵和努力方向;从全国维度总结提出了持续推进森林城市建设的10点建议。

新质生产力赋能森林食品产业高质量发展:逻辑机理、现实挑战与实现进路

森林食品产业高质量发展对于贯彻大食物观、保障国家粮食安全具有重要意义。新质生产力作为传统生产力的质变跃迁,为森林食品产业高质量发展带来了新动能。文中阐释了新质生产力赋能森林食品产业高质量发展的逻辑机理,认为发展新质生产力可以为森林食品产业高质量发展提供绿色底色、动力引擎、资源保障和产业支撑;但在具体赋能过程中面临着森林食品产业产品附加值不高、资源开发利用效率低、产业营销理念落后、高素质人才“量质齐缺”等现实挑战。据此,提出了新质生产力赋能森林食品产业高质量发展的实现进路:1)加强面向现代化产业体系的人才队伍建设,充分发挥森林食品产业新型人才创造力;2)激发产业创新活力,促进森林食品全产业链创新发展;3)完善政策引导机制,加快培育森林食品产业新型经营主体。

政策性森林保险高质量发展时空演进及影响因素分析

在全球气候变化加剧和我国经济高质量发展的关键交织时期,政策性森林保险实现高质量发展对提高林业适应气候变化能力与深化集体林权制度改革具有重要意义。文章基于2013—2021年面板数据,利用赋权法和核密度估计,定量化测度政策性森林保险高质量发展水平并分析其时空演变特征,然后利用双向固定效应模型探讨政策性森林保险市场需求与市场集中度对其高质量发展的影响,验证政府财政保费补贴的调节效应。研究发现:第一,随着时间的推移,我国政策性森林保险高质量发展水平具有缓慢提升的趋势,全国平均值稳定在0.20~0.30之间,但仍处于低发展水平阶段。第二,我国政策性森林保险高质量发展的区域不平衡较为明显,西部地区的平均值(0.40)高于东中部地区(0.26),存在两极分化的现象,“马太效应”愈加明显,但地区不平衡性逐渐得到缓解。第三,目前政策性森林保险高质量发展的主要驱动力仍是“量的扩张”(0.54),“质的提升”(0.46)未来发展潜力巨大。第四,森林保险市场需求扩张和市场集中度降低是政策性森林保险实现高质量发展的内生动力,同时财政保费补贴的调节效应较为明显,强化了市场需求对其高质量发展的正向影响,但未削弱市场集中度的负向作用。基于此,文章提出引导林业经营主体主动投保、鼓励政策性森林保险市场适度竞争以及实施差异化保费补贴政策等政策启示。

广西南亚热带不同森林类型土壤细菌群落多样性及其与土壤化学性质相关分析

【目的】探究不同森林类型土壤细菌群落的多样性和组成,以及土壤细菌群落与土壤因子间的相关性,为掌握华南地区森林生态系统土壤细菌群落结构提供参考依据。【方法】采用高通量测序技术结合土壤理化性质试验,对土壤细菌群落结构进行分类鉴定,测定土壤pH、含水率、有机质(OM)、碱解氮(AN)、速效磷(AP)、速效钾(AK)、钙(Ca)、镁(Mg)、总酚、复合态酚及水溶性酚等理化指标;分析桉树林、马尾松林、马尾松石栎针阔混交林及桂花林土壤细菌群落多样性差异。【结果】通过测序从4种森林类型土壤样品中共得到内生细菌有效序列731289条,注释得到6320个操作分类单元(OTUs),共有2界36门85纲116目136科152属57种。其中,优势细菌门分别是变形菌门(Proteobacteria,33.16%)、放线菌门(Actinobacteria,30.24%)、酸杆菌门(Acidobacteria,16.83%)及绿弯菌门(Chloroflexi,6.71%),优势菌属分别是红游动菌属(Rhodoplanes,7.72%)、分枝杆菌属(Mycobacterium,2.82%)、Candidatus_Solibacter(1.57%)、慢生根瘤菌属(Bradyrhizobium,0.91%)及伯克霍尔德氏菌属(Burkholderia,0.67%)。不同森林生态系统中,桂花林的土壤细菌群落丰富度和多样性均最高,其次是桉树林和马尾松林,针阔混交林最低。冗余分析结果显示pH(r=0.943)、AK(r=0.861)对细菌群落结构均有极显著影响(P<0.01),其中,细菌在门分类水平上影响程度排序依次为p H>AK>复合态酚>总酚>Ca>Mg>AP>水溶性酚>OM>AN,在属分类水平上排序依次为pH>AK>Ca>Mg>AP>总酚>复合态酚>AN>水溶性酚>OM。【结论】4种森林类型土壤细菌群落多样性和丰度受土壤化学性质中pH和AK影响最大,部分门分类水平细菌受土壤酚类物质的影响较大。

三沙湾大黄鱼野生和养殖群体的幽门盲囊微生物群落结构比较分析

大黄鱼(Larimichthys crocea)幽门盲囊呈半封闭结构,保留了部分早期孵化阶段的微生物特征,是用于野生和养殖群体溯源的理想部位。本研究采用高通量测序技术,对三沙湾大黄鱼野生和养殖群体的幽门盲囊微生物的α多样性、核心菌群相对丰度、网络关系等进行分析,构建随机森林模型进行群体溯源分析。结果显示,养殖群体的幽门盲囊微生物有着更多特有操作分类单元(Operational Taxonomic Unit,OTU),其α多样性显著高于野生群体。幽门盲囊微生物的优势菌群有变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)、放线菌门(Actinobacteria)及酸杆菌门(Acidobacteria),且各菌群在野生和养殖群体中的相对丰度差异显著。微生物网络分析结果显示,野生和养殖群体的幽门盲囊微生物群落结构差异明显,野生群体拥有更高的负边缘/正边缘比率和模块性以及更少的节点数和连接数。基于此,我们构建了随机森林分类群体溯源预测模型,其准确率(Accuracy,ACC)达92.31%,Kappa系数为0.8452,ROC曲线下面积为0.9524,利用此模型识别三沙湾大黄鱼野生和养殖群体的准确率分别可达91.67%和92.86%。综上所述,三沙湾大黄鱼野生和养殖群体的幽门盲囊微生物群落结构差异显著,利用幽门盲囊微生物追踪鱼类来源的方法是可行且有效的,研究结果为区分三沙湾大黄鱼野生和养殖群体提供了新思路。

闽楠高效栽培技术

闽楠作为珍贵用材树种,具有适应性强、分布范围广和林木蓄积量高的特点,是主要的商品材树种之一,开发利用前景广阔。本文从闽楠的生物生态学习性、良种选择、壮苗培育、造林技术和抚育管理等方面介绍了该树种的高效栽培技术,为闽楠人工造林和开发利用提供参考。

高质量视域下长三角城市韧性特征及影响机制

长三角地区作为全国高质量经济发展重要的增长极,其城市韧性的提高对推动该地区高质量协同发展和构建城市安全具有重要意义。借助熵值法、泰尔指数、随机森林等方法,使用2010—2020年面板数据并探讨该地区城市韧性特征及影响因素。结果表明:①长三角高质量城市整体韧性、城市韧性发展水平、城市韧性创新指数均呈上升趋势,且创新指数增长率最快,为196%;②研究区内泰尔指数、Gini系数减小,说明该区城市韧性差异整体缩小了;③空间演进上,研究区内呈明显分异,其城市韧性等级结构沿中心区向外呈递减特征,并在空间分布上形成以上海和苏州等市为HH集聚区,以皖北和苏北地区为LL特征;④政府政策、创新科技、区域经济发展等主体是高质量城市韧性发展的影响机制,主要包括人才集聚、企业发展及政策环境等。

基于NGO-CNN-SVM的高标准农田灌溉工程施工成本预测

为提高高标准农田项目施工成本的预测精度,控制施工成本在合理范围,减少投资风险,该研究从单体灌溉工程施工成本预测角度出发,通过随机森林(random forest,RF)筛选出高标准农田灌溉工程施工成本的关键影响因素,结合卷积神经网络(convolutional neural networks,CNN)和支持向量机(support vector machine,SVM)两种模型的优点,通过北方苍鹰优化算法(northern goshawk optimization,NGO)对模型里的惩罚因子和核参数进行寻优,构建基于NGO-CNN-SVM的施工成本预测模型。通过辽宁省2018—2023年高标准农田工程中灌溉工程的施工成本数据,选取样本决定系数R^(2)、平均绝对误差MAE、平均绝对百分比误差MAPE和均方根误差RMSE作为精度指标进行分析,结果表明:基于NGO-CNN-SVM的施工成本预测模型在渠道工程中MAE低于0.615万元,RMSE低于0.512万元,R^(2)达到0.968以上,相对误差小于4.210%;在进水闸工程中MAE低于0.610万元,RMSE低于0.536万元,R^(2)达到0.966以上,相对误差小于4.410%;在桥涵工程中MAE低于0.494万元,RMSE低于0.477万元,R^(2)达到0.970以上,相对误差小于3.548%,并相比较于反向传播神经网络,CNN和CNN-SVM模型,NGO-CNN-SVM模型的预测结果均最优。通过特征选择、模型融合、算法优化以及不同模型对比表明NGO-CNN-SVM模型具有更高的预测准确率和泛化性,可为高标准农田灌溉工程施工成本预测提供理论依据。

毛竹入侵杉木林对土壤真菌群落多样性的影响

为揭示凤阳山毛竹入侵杉木林后土壤真菌群落结构组成和多样性的变化,采用Illumina Miseq测序技术,分析杉木纯林、毛竹纯林及毛竹入侵后的杉木林真菌群落结构特征。结果表明:3种林型的土壤真菌类群为26门60纲113属415 OTU,子囊菌门和担子菌门是绝对优势的两个菌门。两者的丰度占真菌总量80.80%~83.92%,在3种林型间均不存在显著差异。识别出的1%以上的优势菌纲有8个,为古根菌纲、伞菌纲、粪壳菌纲、锤舌菌纲、银耳纲、球囊菌纲、散囊菌纲和酵母菌纲。古根菌纲和伞菌纲占真菌总量的50.82%~75.40%。古根菌纲在毛杉混交林的相对丰度显著高于毛竹纯林(P<0.05),与杉木纯林无显著差异。Archaeorhizomyces为优势菌属(20.07%~51.51%)且在毛杉混交林中最高、在毛竹纯林最低,毛杉混交林中全氮、碱解氮和速效钾含量均显著低于杉木纯林和毛竹纯林。土壤真菌优势菌属水平丰度与土壤环境因子的斯皮尔曼相关性分析表明,全磷与Meliniomyces、毛壳菌属、Hodophilus、瓶霉属、Heterocephalacria呈显著正相关(P<0.05),与Wickerhamomyces呈极显著正相关(P<0.01)。毛竹入侵杉木林后土壤理化性质变化显著,全磷、有效磷、pH、速效钾和碳磷比是影响土壤真菌群落结构的主要环境因子,研究结果可为控制毛竹扩张,维护生态稳定和多样性提供科学依据。