Spruce-fir Forests Research Articles

川西米亚罗自然保护区森林地上碳储量遥感估算

PDF HTML阅读 XML下载 导出引用 引用提醒 川西米亚罗自然保护区森林地上碳储量遥感估算 DOI: 10.5846/stxb201807281610 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 四川省科技厅应用基础项目（2017JY0155）；四川省中医药管理局重大专项（2018PC005） Estimation of forest aboveground carbon storage in Sichuan Miyaluo Nature Reserve based on remote sensing Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:研究米亚罗自然保护区的森林地上碳储量，有利于掌握高山峡谷区森林植被碳储量的分布特点，对区域森林资源的有效科学管理和维护森林生态环境具有重要意义。通过对保护区内的7个主要树种分别构建模型来初步估测森林地上碳储量，利用实地调查的样地数据与同期Landsat 8遥感卫星影像，得到波段信息、植被指数、主成分分析、纹理特征、地形因子、植被生长六大类共80个因子，用以构建乔木层不同树种地上碳储量的多元线性逐步回归模型，而灌木层的碳储量则由生物量密度法估算得出。研究结果表明：①模型预测值与实测值相关系数在0.675-0.775之间，精度较高，预测结果可靠；②米亚罗自然保护区森林地上碳储量为5.861 Tg，其中乔木层5.632 Tg，灌木层0.229 Tg。云冷杉林是研究区分布最广的林分类型，其碳储量为5.098 Tg，占森林地上碳储量总量的86.98%，在维持区域碳平衡方面发挥着重要作用。③研究区森林平均碳密度为53.138 t/hm2，其中冷杉的碳密度最高，达到74.467 t/hm2。④区域内森林地上碳储量以杂谷脑河流域及支流为中心，以一定缓冲距离呈树枝状发散分布，海拔3000-4000 m区域的森林植被碳储量最大，且阴坡的碳储量明显高于阳坡。 Abstract:The Miyaluo Nature Reserve is an important carbon sequestration region in Western Sichuan. Study of aboveground forest carbon storage in Miyaluo Nature Reserve is necessary for elucidating the distribution characteristics of forest vegetation carbon storage in alpine gorge areas. Furthermore, it is of great significance to the scientific management of forest resources and the maintenance of forest ecological environments in the nature reserves. In this study, carbon storage models were established for seven main tree species to estimate the carbon storage on forest land. Firstly, 897 samples were obtained from a field survey, and sample biomass and carbon storage were calculated based on the volume-derived biomass method. Secondly, Landsat 8 satellite remote sensing data were used to obtain image characteristics of forest vegetation. Thirdly, combined with forest survey data, 80 factors were determined that were classified into six categories (band information, vegetation index, principal component analysis, texture features, topographic factors, and vegetation growth). Moreover, the correlation between these factors and the biomass of different tree species was analyzed, according to the order of Pearson's correlation coefficient, the significant correlation factors were then introduced into the multiple linear stepwise regression equation as independent variables, and the estimation models of aboveground carbon storage of different tree species in the tree layer were established. Finally, the aboveground carbon storage of the arbor layer was calculated by the estimation model, and the carbon storage in the shrub layer was calculated using the average biomass density method. The results showed that ① the accuracy of models for carbon storage estimation was within the margin of error, and the correlation coefficient between the measured value and the predicted value of the model was 0.675-0.775. ② The total carbon storage in the forest in the Miyaluo Nature Reserve was 5.861 Tg, of which the aboveground carbon storage in the arbor layer was 5.632 Tg, and the carbon storage in the shrub layer was 0.229 Tg. The order of the aboveground carbon storage of the prominent species was Abies faberi > Picea asperata > Tsuga chinensis > Larix gmelimi > Quercus acutissima > Betula chinensis > Pinus tabulaeformis > Pinus armandi; The total carbon storage of fir trees was 5.098 Tg, accounting for 86.98% of the aboveground carbon storage in the study area. The spruce-fir forest was the most widely distributed forest type in the Miyaluo Nature Reserve, and it played an important role in maintaining the carbon balance. ③ The average carbon density in the forest in Miyaluo Nature Reserve was 53.138 t/hm2, and the carbon density of Chinese fir species was higher than the average. The carbon density of fir was much higher than that of other tree species and was 74.467 t/hm2. ④ The spatial distribution characteristics of aboveground forest carbon storage in the study area were obtained by overlapping the Digital Elevation Model (DEM) with carbon storage. Taking the Zagunao River and its tributaries as the center, the carbon storage spatial distribution data were extended to the surrounding area by a given buffer distance in the whole region, similar to arborization. The largest area of forest vegetation carbon storage was distributed in regions with elevation of 3000-4000 m. The aboveground carbon storage on shady slopes was higher than that on sunny slopes. 参考文献 相似文献 引证文献

Tall herb dark coniferous forests as modern refugia of biological diversity of Northern Eurasia (on example of Pechora-Ilych Nature Reserve)

Reconstruction of prehistoric forests can be based on restoring the areas of key species of plants and animals in those still preserved in refugiua which include tall herb forests. The main characteristic of unique boreal tall herb spruce-fir forests (association of Aconito septentrionalis-Piceetum obovatae) is presented in comparison with green moss spruce-fir forests (Eu-Piceetum abietis) that dominate in the taiga zone. Using the example of tall herb forests in the Pechora-Ilych Nature Reserve, we identified the following signs of intact forests of the Northern Eurasia: high diversity of vascular plant and moss species; full set of microsites connected with a tree-falls, well-defined gap-mosaic; diversity of ecological-coenotic groups; uneven-aged structure of tree species populations; fertile soil and rich soil biota; presence of broad-leaved forest markers such as ephemeroids (Corydalis solida, Anemone spp., Gagea spp., etc.); presence of broad-leaved tree species in paleo-spectra. The northern dark coniferous forests may also be regarded as historic refugiua because they were less disturbed by humans and probably less exposed to fire. Such model reconstructions will form the basis for developing methods for restoring the pre-anthropogenic dark coniferous (taiga) forests of Northern Eurasia.

Aerial spraying of bacterial insecticides to control spruce budworm defoliation leads to reduced carbon losses

AbstractSpruce budworm (SBW) outbreaks are a major natural disturbance in boreal forests of eastern North America. During large‐scale infestations, aerial spraying of bacterial insecticides is used to suppress local high‐density SBW populations. While the primary goal of spraying is the protection of wood volume for later harvest, it should also maintain carbon stored in trees. This study provides the first quantitative analysis of the efficacy of aerial spraying against SBW on carbon dynamics in balsam fir, spruce, and mixed fir–spruce forests. In this study, we used the TRIPLEX‐Insect model to simulate carbon dynamics with and without spray applications in 14 sites of the boreal forest located in various regions of Québec. We found that the efficacy of aerial spraying on reducing annual defoliation was greater in the early stage (<5 yr since the outbreak began) of the outbreak than in later (5–10 yr since the outbreak began) stage. Our results showed that more net ecosystem productivity is maintained in balsam fir (the most vulnerable species) than in either spruce or mixed fir–spruce forests following spraying. Also, average losses in aboveground biomass due to the SBW following spraying occurred more slowly than without spraying in balsam fir forests. Our findings suggest that aerial spraying could be used to maintain carbon in conifer forests during SBW disturbances, but that the efficacy of spray programs is affected by host species and stage of the SBW outbreak.

РАСТИТЕЛЬНОСТЬ ООПТ «БОЛЬШЕСИТОВСКОЕ БОЛОТО» (ПЕРМСКИЙ КРАЙ)

The results of studying the vegetation of the specially protected natural area "Bolshesitovskoe swamp" are presented. Several types of forest, meadow, and bog associations were identified on the territory of the surveyed area. The predominant types of forests in this area are light-coniferous (pine forests): green moss pine forests (lingonberry pine forests and blueberry pine forests), sphagnum pine forests, small areas of moss-lichen pine forests are noted. Dark coniferous forests are represented by green moss spruce forests, horsetail spruce forests, sphagnum spruce forests, large-fern fir-spruce forests, and green moss fir-spruce associations. Pine-spruce green moss forests are found. Mixed forests are represented by pine-birch and birch-pine forests, spruce-birch herb and horsetail associations. Swamps are represented by upland, low-land and transitional types. Meadow vegetation is present only in areas disturbed by humans and in the floodplain of the river. Yaiva (very small areas of floodplain meadows). Depending on the degree of mois-ture in disturbed areas, barren meadows and boggy meadows (close to lowland or raised bogs) are formed.

Runoff components of small catchments in Sikhote-Alin: summarizing the results of field measurements and tracer modeling

The article summarizes results of the systematic study of the streamflow formation of two small catchments in the upper part of the Ussuri River. The study was carried out by the hydrograph separation technique (using detailed data of the hydrochemical and hydrological monitoring) and the use of a tracer mixing model in conjunction with EMMA. Performed in the period from 2011 to 2016 the studies allowed to calculate the river runoff components of the summer-autumn period at 3 gauge-stations and evaluate their mutual dynamics at different time scales. It is shown that in the case of landscape uniformity of the catchment (the Medvezhiy Creek), the river flow can be represented as a result of 3 sources mixing. This, the most common, scheme for the hydrograph separation includes following sources: a direct rainfall flow, an organic soil water component, and an underground baseflow. If the catchments landscape structure is clearly heterogeneous (the Elovy Creek), the river flow can be represented as a result of 4 sources mixing. In this case, the fourth source appears as a result of the separation of soil water component into individual components organic and mineral. This separation is due to the spread in the basin of the cold upper belt of fir-spruce forests, whose soils are characterized by a lower rate of organic matter destruction and a deeper illuviation process of DOC. Statistically significant dependencies of the some runoff components proportions against river discharges were identified, systematization of which makes them promising for practice in hydrological monitoring and forecasting.

Biotopic Association of Earthworms in Intact Forests of Teberda Nature Reserve

Contribution of micromosaic structure of high mountain forests to ecological diversity of earthworms have been assessed. Intact forests of Arkhyz section of Teberda Nature Reserve were studied. The dominant types of forests have been recognized for the first time based on eco-coenotic classification. The ecological conditions of their functioning have been studied. Earthworm numbers have been studied in the recognized forest types. Diversity of earthworms was studied in soils under crowns, under fallen trees, and in mosses growing on rocks. 16 species of Lumbricidae have been found, with 4 of them being discovered for the first time. Full complexes of Lumbricidae were associated with biotopes of forest types of increased soil moisture content, low acidity, availability of nitrogen and pronounced litter. The largest abundance, diversity and biomass of Lumbricidae have been found in nitrophilous tallgrass gray alder forests. The lowest have been found in xeromesophytic pine forests with fir, spruce and birch. The most widespread dark coniferous forest with beech were inhabited by seven species of Lumbricidae, dominated by the epigeic species. There were few epi-endogeic and anecic species. The endogeic group of earthworms was represented by Crimea and Caucasus subendemic Dendrobaena schmidti. Diversity and biomass of earthworms in dark coniferous forests with beech were higher than in spruce-fir forests. During summer, dead fallen trees served as a microsite preferential for epigeic and endogeic species, while mosses growing on rocks were preferred by endogeic species.

Acidic Deposition and Climate Warming as Drivers of Tree Growth in High-Elevation Spruce-Fir Forests of the Northeastern US

Acid rain in eastern North America contributed to the widespread decline of red spruce in high-elevation spruce-fir forests. With recent reductions in acid deposition and a warming climate, resurgence of red spruce growth has been reported in some mountain areas. Based on an extensive tree-ring sampling network established across elevations (600 to 1200 m above sea level) in spruce-fir forests on 10 mountains in the northeastern US (New York, Vermont, New Hampshire, and Maine), we investigated whether this resurgence was specific only to red spruce or if it occurred also in the codominant balsam fir. Furthermore, we tested if tree growth changes for both species were related to recent trends in acidic deposition and climate. Sharply increasing growth rates of red spruce were evident at all elevations and most closely correlated with increasing rainwater pH. Although climate of the previous year (cool July and warm November) explained higher spruce growth in certain years, recent trends in climate did not drive observed increases in spruce growth. In contrast, balsam fir exhibited no regional growth surge during the period of spruce recovery. Thus, spruce growth resurgence appears to be mediated primarily by declining acid deposition and not climatic changes or stand dynamics that would also impact fir growth. Although high-elevation forests may ultimately be at risk for future warming-related heat and drought stress, the observed recent dramatic resurgence of spruce growth illustrates the benefits of policy-driven reductions in acidic deposition for the health and productivity of northeastern US forests.

Above-ground carbon stock in merchantable trees not reduced between cycles of spruce budworm outbreaks due to changing species composition in spruce-fir forests of Maine, USA

Disturbances are a primary force regulating the successional development and associated carbon cycling in forest ecosystems, but our understanding of these dynamics is based on studies mostly limited to relatively homogeneous and high intensity forest disturbances such as harvesting and wildfire. Contrarily, extensive insect defoliations such as that caused by spruce budworm (SBW; Choristoneura fumiferana (Clem.)) often are species-specific and vary greatly in their intensities and consequent influences on forest carbon dynamics over large spatial and temporal extents. In this study, we applied an individual tree growth model across a large forested area in the state of Maine, USA to simulate the impact of SBW outbreaks on above-ground carbon stock in merchantable trees, which is the primary carbon pool of interest in forest management and its associated downstream industries. The model, the Acadian Variant of the Forest Vegetation Simulator (FVS-ACD), provides the necessary resolution needed to capture the spatio-temporal variability in SBW defoliation and its impacts on the mixed species, structurally complex spruce-fir (Picea-Abies) forests of Maine. Our evaluation of two 40-year SBW outbreak cycles (1975–2015 and 2017–2057) indicates that, due primarily to changing species composition (particularly significant increases of hardwood species), this carbon stock of spruce-fir forests was not reduced and not significantly different than what it would be without an outbreak at the end of either cycle. However, there were temporary decreases in carbon growth immediately following these outbreaks. These decreases were at smaller scales in the 40-year cycle starting 2017 where significant increases of hardwood species along with decreases of SBW's primary host species were observed. As this trend of changing species composition continues in this region, a future SBW outbreak would cause less reduction in carbon growth and less likely to result in a decrease of carbon stock in spruce-fir forests. Overall, the utilized tree-level modeling framework may prove useful for assessing the influence of complex disturbances like insect defoliation in other regions.

Vegetation pattern of Northeast China during the special periods since the Last Glacial Maximum

Since the Last Glacial Maximum (LGM), the global climate has experienced several stages, such as cold and warming events, which provide an ideal model for evaluating climate change in the future. Based on the pollen records in Northeast (NE) China, the vegetation pattern during special periods since the LGM was reconstructed in this work. During the LGM (approximately 18,000 cal yr BP), the steppes expanded rapidly in NE China, and a cold-dry meadow-steppe developed on the Songnen Plain. The Liaohe Plain and the Hulun Buir Plateau were occupied by a steppe-desert, with forest-steppe vegetation grown in the central and southern plains; there were cold-dry coniferous forests and mixed conifer-broadleaf forests in mountainous areas. In the early Holocene (10,000–9,000 cal yr BP), Changbai mountain (CBM) forests thrived in the eastern hilly area and the Sanjiang Plain, while the central region was dominated by steppes, and warm-temperate broadleaf forests developed northward. During the Holocene warm period (approximately 6,000 cal yr BP), CBM forests and cold-temperate coniferous forests developed in the north, while spruce-fir forests developed in the eastern Xiao Hinggan Mountains and the Sanjiang Plain. The distribution centre of deciduous broadleaf forests migrated to the south of the Changbai Mountains and the Liaodong Peninsula. The isolated woodlands increased on the Songnen Plain and the meadow-steppes expanded to the Liaohe Plain. Therefore, the increase in temperature leads to the increase of monsoon precipitation in NE China, which is beneficial to the development of warm-temperate forest vegetation. The increase of summer monsoons and precipitation caused by climate warming may be the main reason for the improved plant load.

Environmental Conservation in Western Himalayas: Sustainable Management of Spruce and Silver Fir Forests. By Prof. R.V. Singh, IFS (Retd.)

Environmental Conservation in Western Himalayas: Sustainable Management of Spruce and Silver Fir Forests. By Prof. R.V. Singh, IFS (Retd.)

The Role of Microsites in the Natural Regeneration of Trees in Boreal Tall-Herb Dark Coniferous Forests of the Northern Urals

This paper presents the results of research into the role of various types of microsites (flat under- and intercrown areas, stumps, fallen logs, mounds, and pits) in the natural regeneration of trees in uneven-aged dark coniferous boreal tall-herb spruce–fir forests of the northern Urals. Areas of microsites of various types have been identified; a general description of natural tree regeneration is provided; the association of undergrowth of various tree species with different microsites was determined; and the undergrowth distribution by ontogenetic states has been assessed. The lowest undergrowth density was registered on flat sites occupying the major part of the community area, while the highest density was detected on elevated microsites (fallen logs, stumps, and mounds) the total area of which is pretty small. The highest density of the undergrowth of all species was observed on stumps. On mounds and fallen logs, it was 4.3 and 3.0 times lower, respectively. It is shown that elevated microsites (stumps, fallen logs, and mounds) are required for successful survival of the undergrowth of various tree species in boreal tall-herb forests.

Initial Stages of Recovery of Soil Macrofauna Communities after Reduction of Emissions from a Copper Smelter

Analysis of natural recovery of communities after reduction of industrial emissions is important for gaining an insight into their stability. However, there is obvious deficit in observations on the course of this recovery; in particular, no data on direct comparisons of the state of communities before and after reduction of emissions are available for soil macroinvertebrates. We have studied the structure of soil macrofauna communities at the level of supraspecific taxa in southern taiga spruce-fir forests in the region exposed to emissions from the Middle Ural Copper Smelter (MUCS; Revda, Sverdlovsk oblast). The data over three periods—high, reduced, and almost terminated emissions (1990–1991, 2004, and 2014–2016, respectively)—have been compared to test the hypothesis that the communities do not recover rapidly. The results partly confirm this hypothesis. On the one hand, the response of pedobionts to pollution at a qualitative level has remained basically unchanged: in each of the three periods, their total abundance (and that of the majority of groups) decreased abruptly as the MUCS was approached, with dominance shifting from saprophages to phyto- and zoophages. On the other hand, signs of recovery have appeared during the last period: the abundance of pedobionts has increased, and pollution-sensitive groups (earthworms, enchytraeids, and mollusks) have approached closer to the MUCS. This is most likely explained by decrease in the toxicity of metals due to normalization of soil pH. Rapid recolonization of defaunated territory may be accounted for by the presence in it of microsites with more favorable conditions, compared to the surrounding area, which allow low-mobile forms to survive beyond the boundaries of their main distribution area.

Timber Losses from West Fork Complex Fire in Southwest Colorado

Abstract This article provides an assessment of fire effects on timber burned in the West Fork Complex fire area, located in the San Juan Mountains of Colorado. The West Fork Complex fire burned 109,615 acres in 2013, and suppression costs alone totaled $33.2 million. Much of the fire occurred in spruce–fir forests that were previously affected by spruce beetle (Dendroctonus rufipennis). Several timber sales were actively occurring within the fire footprint, and more were anticipated to begin in subsequent years. To provide a more accurate valuation estimate, base log stumpage data from 2003 through 2017 were included in this study to show high degrees of variation over time. With base log stumpage values determined, estimates of total hundred cubic feet of each significant species were calculated using geospatial and forest inventory analysis data. This study determined the timber value loss resulting from the coupled disturbance events of the spruce beetle epidemic and a wildland fire to be $19,083,102. This estimate will allow for a more accurate valuation of the actual damage resulting from the West Fork Complex fire. This study may also be useful in supporting the literary basis for salvage and fuels management after a beetle outbreak to prevent such timber value losses from occurring.

四川省森林植被固碳经济价值动态

PDF HTML阅读 XML下载 导出引用 引用提醒 四川省森林植被固碳经济价值动态 DOI: 10.5846/stxb201809292123 作者: 作者单位: 四川农业大学林学院,重庆大学经济与工商管理学院,四川农业大学林学院,四川农业大学林学院,四川农业大学林学院,四川农业大学林学院 作者简介: 通讯作者: 中图分类号: 基金项目: 长江上游生态安全协同创新中心开放基金项目；成都市森林碳储量及增汇潜力研究（2017-Y2500W-17） Economic value dynamics of carbon sequestration in forest vegetation of Sichuan Province Author: Affiliation: college of forestry，Sichuan Argicultural University,Chongqing University,college of forestry，Sichuan Argicultural University,college of forestry，Sichuan Argicultural University,college of forestry，Sichuan Argicultural University,college of forestry，Sichuan Argicultural University Fund Project: the Foundation of cooperative innovation center of ecological security in the upper reaches of the Yangtze River;Study on forest carbon storage and potential in Chengdu 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:正确估算森林植被固碳经济价值可为森林生态系统的生态效益评价提供基础数据。利用1997年和2014年两期四川省森林资源清查数据，依据不同森林类型的生物量与蓄积量回归方程和支付意愿法，估算了四川省两个时期森林植被的固碳经济价值。结果表明，从1997年到2014年，四川省森林植被固碳经济价值由703.17亿元增长到865.75亿元，净增长162.58亿元，年均增长9.56亿元，年均增长率为1.36%；在两个时期，云冷杉林的固碳经济价值比重最大，分别占总固碳经济价值的54.82%和46.62%，表明云冷杉森林植被类型在全省森林植被固碳经济价值中占有重要的地位；四川省天然林和人工林植被的固碳经济价值均呈增加趋势，并且人工林植被固碳经济价值年均增长速率（7.42%）明显高于天然林（1.03%）；四川省森林植被固碳经济价值总体上随林龄的增加而增加。研究结果说明，实施包括天然林保护工程在内的森林保护和经营管理措施对提高森林植被的固碳经济价值具有重要的作用。 Abstract:Correctly estimating the economic value for the sequestration of carbon in forest vegetation can provide basic data for the evaluation of eco-benefits in forest ecosystems. We used forest resource inventory data of Sichuan Province from 1997 and 2014 to estimate the economic value of forest carbon sequestration in Sichuan Province in two periods. The results show that from 1997 to 2014, the economic value of forest carbon sequestration in Sichuan Province increased from 70.317 billion yuan to 86.575 billion yuan. The net increase was 16.258 billion yuan and the average annual growth was 0.956 billion yuan, with an average annual growth rate of 1.36%. In 1997 and 2014, spruce fir forest had the largest economic value, which accounted for 54.82% and 46.62% of the total carbon sequestration economic value, respectively. This indicates that spruce fir forest plays an important role in the economic value of forest carbon sequestration in the province. The economic value of carbon sequestration in natural forests and planted forests in Sichuan Province showed an increasing trend, and the economic value in planted forests (7.42%) was significantly higher than that in natural forests (1.03%). The economic value of forest carbon sequestration in Sichuan Province generally increased with the increase of forest age groups. The results show that the implementation of forest protection and management measures, including natural forest protection projects, played an important role in improving the economic value of forest carbon sequestration. 参考文献 相似文献 引证文献

Influences of stand, soil and space factors on spatial heterogeneity of leaf area index in a spruce-fir valley forest in Xiao Hinggan Ling, China

Influences of stand, soil and space factors on spatial heterogeneity of leaf area index in a spruce-fir valley forest in Xiao Hinggan Ling, China

Effects of decay level of fallen trees and their formed microsite types on soil physicochemical properties in a spruce-fir forest.

To reveal the effects of decay level of fallen trees and their formed microsite types on soil physicochemical properties, the differences in soil physicochemical properties (bulk density, capillary porosity, total porosity, capillary water holding capacity, saturated moisture capacity, soil organic carbon, total nitrogen, total phosphorous, available phosphorous, available potassium, and pH) and stoichiometry (C/N, N/P, and C/P) among different decay levels of treefalls and between different microsite types in the formed gaps by fallen trees were analyzed in a spruce-fir fore-st in a valley of Liangshui National Nature Reserve in Xiaoxing' an Mountains. The results showed that the effects of the decay levels of fallen trees on soil physical properties was not significant. In contrast, we found significant effects of the formed microsite types in soil physical properties. Except for saturated soil water holding capacity, the other soil physical properties were the best under the fallen trees and the worst in the pit bottom. Except of available phosphorus, the contents of the other soil nutrients exhibited a significant increase trend with the increasing decay levels of fallen trees. Among three microsites, the contents of soil nutrients were the lowest and pH were highest in the pit. As for the shallow soil layer, C/N, N/P and C/P of three microsites decreased with the increasing decay levels of fallen trees, while C/N in mound top and in pit bottom increased, N/P and C/P decreased, and the variation of C/P was consistent with that of available phosphorus. In conclusion, with the increasing decay levels of fallen trees, the contents of soil nutrients were signifi-cantly increased. There are significant differences of soil nutrients among different microsites, with the lowest values in the pit.

Density has more influence than drought on spruce budworm (Choristoneura fumiferana) performance under outbreak conditions

Eruptive insect pests have significant impacts on the structure and function of forest ecosystems. Outbreaks of spruce budworm (Choristoneura fumiferana) (Clem.), for instance, occur approximately every 35–40 years, resulting in the loss of millions of hectares of spruce–fir forests in eastern North America. In addition to the density-dependent relationships that drive insect outbreaks, rising populations often coincide with drought events, which are expected to increase in both frequency and intensity in response to climate change. However, as populations approach the eruptive phase, consequences of intraspecific competition may outweigh the benefit of host water stress. The objective of our study was to quantify defoliation and insect performance responses to the interactive effects of drought and density of spruce budworm. To test for these interactions, we established a manipulative field experiment in a mature, balsam fir-dominated forest stand using a combination of single-tree rainout shelters and sleeve-caged insect larvae at four different densities: 0, 25, 50, or 100 individuals.Defoliation of 1-year old shoots, but not current-year shoots, significantly increased in response to higher insect densities. Density also had a significant, negative effect on budworm percent survival, although the total number of recovered adults remained highest in the high density treatment. Adult female body mass was significantly reduced in response to increased density, but only on droughted trees. Lastly, male wing length was significantly decreased in response to increased density. Overall, our results demonstrate that across a broad range of outbreak densities, rain exclusion had a minor impact. Accordingly, we anticipate that as insect pest populations approach epidemic levels, the influence of density on defoliation, insect survival, and body condition is likely to outweigh the impact of moderate drought stress.

Socioecological Impacts of Multiple Forest Insect Outbreaks in the Pinaleño Spruce–Fir Forest, Arizona

Socioecological Impacts of Multiple Forest Insect Outbreaks in the Pinaleño Spruce–Fir Forest, Arizona

Records of Tengmalm’s Owl (Aegolius funereus) from the Šar Mts, Republic of Macedonia

Three localities of the Tengmalm’s owl (Aegolius funereus) were recorded during a field trip in the Šar Mts, North-western Republic of Macedonia. The study was conducted in October, 2015. The species was found to inhabit spruce and spruce-fir forests at altitudes between 1436 and 1848 m a.s.l. That finding is the first evidence of the presence of the Tengmalm’s owl in the Macedonian part of the Šar Mts and one of the very few published records for the occurrence of the species in the Republic of Macedonia.

Soil mesofauna and diversity of vegetation: Collembola in pristine taiga forests (Pechora-Ilych Biosphere Reserve, Russia)

Unique 600-year-old tall herb taiga forests are located in the European North-East of Russia at the foothills of the Middle Urals and are characterized by extremely diverse and vertically differentiated vegetation. This study addresses how vegetation parameters such as net primary productivity and diversity influence the community structure of Collembola in fir forests of different ages. Sample plots were arranged along diversity and biomass gradients of vegetation: Vaccinium-moss, short herb-moss, and nitrophilous tall herb fir–spruce forests. Plants and collembolans were compared with respect to their species richness, abundance, species structure and traits. The number of species of vascular plants, mosses and liverworts along the studied gradient increased by about double, whereas the species richness of collembolans did not differ significantly. The biomass of vascular plants increased, whereas that of mosses declined, and the abundance of collembolans remained approximately consistent. Despite sharp differences in ground vegetation, in all phytocenoses the dominant Collembola species were widespread. However, the collembolan community of old-growth tall herb forests showed a trend of more complex structure reflected by greater evenness of abundances compared to younger ecosystems with less diverse ground vegetation. In conclusion, the springtail communities in forests that have developed spontaneously for over 600 years appeared to be no more complex than those in 200-year-old stands. Multi-species ground vegetation did not increase collembolan diversity and abundance indices. Thus, soil mesofauna (in this case, springtails) appeared to be relatively independent of long-term spontaneous development in vegetation in the studied area.