Forest Nature Reserve Research Articles

Assessment and Mapping of Land Cover/Use Aided by Remote Sensing and GIS Techniques in Elnour Natural Forest, Blue Nile State, Sudan

The main aim of this study was to assess and mapping of land cover (LC) / land use (LU), using Remote Sensing (RS) and Geographical Information System (GIS) techniques in Elnor natural forest reserve, Blue Nile state, Sudan. The study also attempted to update some information in the study area such as LC and contour map by using different methods of data transformation and analysis such as Normalized Different Vegetation Index (NDVI), interpolation and supervised classification. Thematic Mapper (TM), Landsat Enhanced Thematic Mapper (ETM+) and Landsat8 images were used in LCLU changes and supported by field observation. The study area was affected by cutting the mother trees and overgrazing. Closed forests during 2000, 2010 and 2019 decreased from 36.9%, 28.5% and 18.7% respectively. Moreover, the total area of bare soil increased by about 14.4%, 47.2% and 39.7% in 2000, 2010 and 2019 respectively. The open forest (grassland) decreased from 48.7% in (2000) to 41.7% in (2019). A Digital land cover map was produced using LCCS software; depending on the fieldwork data, they were found in four Classes. Mixed Woodland Single Layer, Semi-Deciduous Shrub land with Open Herbaceous, Open Grassland, Single XII Layer and Hardpans. The study revealed that there are some indicators of land degradation during the last 20 years (2000, 2010 and 2019) and is expected to continue increasing unless serious measures are carried out to reduce it.

Assessing the Fragmentation, Canopy Loss and Spatial Distribution of Forest Cover in Kakamega National Forest Reserve, Western Kenya

Kakamega National Forest Reserve is a tropical forest ecosystem at high risk of irreplaceable biodiversity loss due to persistent human-induced pressures. The aim of this paper is to assess the effect of fragmentation and forest cover loss on forest ecosystems in Kakamega National Forest Reserve, with the objectives: (1) to quantify the forest cover loss and analyse fragmentation in the Kakamega forest ecosystem and (2) to analyse the effect of forest cover loss on the spatial distribution of the Kakamega forest ecosystem at different timescales. Hansen global forest change data was used as an input training dataset on the Google Earth Engine platform (GEE) to estimate the area of forest cover loss by aggregating the sum of pixel values, and to provide a time series visualization of forest change by the extent of cover loss using Sentinel-2 and Landsat 7 false colour composites (RBG) in QGIS software. Fragmentation analysis was performed using reclassified forest loss and distribution data from the Hansen product as binary raster input in Guidos software. Total forest cover loss over 20 years was estimated at 826.60 ha. The first decade (2000–2010) accounted for 146.31 ha of forest cover loss, and the second decade (2010–2020) accounted for 680.29 ha of forest cover loss. Forest area density (FAD) analysis depicted an increase in the dominant layer by 8.5% and a 2.5% decrease in the interior layer. Morphological spatial pattern analysis (MSPA) illustrated a change in the core layer of 96% and a 14% increase in the openings class layer. Therefore, this study demonstrates that forest cover loss and landscape pattern alteration changed the dynamics of species interaction within ecological communities. Fragmented habitats adversely affected the ecosystem’s ability to recover the loss of endemic species, which are at risk of extinction in the backdrop of climate change. Anthropogenic drivers i.e., the clearing of natural forest and conversion of forest land for non-forest use, have contributed significantly to the loss of forest cover in the study area.

Tree biomass, carbon stock characteristics and ground beetles (Coleoptera: Carabidae) diversity in the Uzungwa Scarp Forest Nature Reserve, Tanzania.

Reducing carbon emission from Deforestation and forest Degradation (REDD+) has drawn attention and remain one of the main options for climate change mitigation. However, the extent to which conservation for carbon may enhance biodiversity conservation in both disturbed and relatively undisturbed (control) environment remain unclear in most forest types. The extent to which anthropogenic disturbances affect carbon stock and ground beetle diversity is also far from clear. This paper addressed these knowledge gaps using data based on ground beetles, carbon stock in live trees and tree species sampled in Uzungwa Scarp Nature Forest Reserve (USNFR). All trees with a diameter at breast height (DBH) ≥ 5 cm were measured for height and DBH in twelve clusters of 1 ha in size. In the same clusters, ground beetles were sampled using pitfall traps, active night search and active day search. The species diversity of ground beetles differed significantly between control sites and disturbed sites (p < 0.05). The mean total biomass and carbon stock in live trees were high in disturbed sites (323.72 t/ha) when compared to control sites (289.72 t/ha) but the difference was not statistically significant (U = 14, p > 0.05). Carbon in live trees and ground beetle diversity showed a weak positive correlation, while richness and abundance showed weak negative in control sites. Results show that REDD+ related activities in a tropical forest may enhance ground beetle diversity and carbon stock if ground beetles conservation is explicitly taken into account. Thus forest conservation planning that pursues both carbon storage and ground-dwelling invertebrate diversity is recommended.

Cultivating Cannabis in a paraguayan nature reserve: Incentives and moral justification for breaking the law

Paraguay has become the main cannabis producer in South America and one of the largest exporters in the world. Some investigations about the cultivation of marijuana in the country portray a cruel environment in which peasants are exploited in “almost feudal” conditions by intermediaries who buy their crops at unreasonably low prices. However, a group of peasants who use the Mbaracayú Forest Nature Reserve as their labour area have created a safe and profitable ecosystem for developing their business. Based on interviews with key informants and visits to the area, the article describes the constraints and incentives that lead those peasants to engage in criminal activities, the strategies they have used to establish protective barriers, and the moral justifications that emerge as a result of their success in doing business. Although there are violent practices and extortion, we claim that the decision-making process to get involved in illegal markets is a free action influenced by alternative moral understandings that provide reasons and justifications for breaking the law. The moral map of these cannabis growers goes far beyond the mere economic justification of generating material resources and is related to economic, institutional, and social premises linked to a generalized aspiration of dignity and a life worth living. The functioning of informal institutions learned through previous interactions with state and non-state actors who regulate and protect the market, the perceived social approval/legitimation of the activity by referent groups, and the awareness of the capacity and skills necessary to successfully conduct the business have a crucial importance in the moral reformulation.

Changes in Forest Stand and Stability of Uropodine Mites Communities (Acari: Parasitiformes) in Jakubowo Nature Reserve in the Light of Long-Term Research

The current study has been conducted for over 40 years (between 1981 and 2022) in a natural forest reserve in Jakubowo (western Poland). The material for the analysis was collected in three permanent monitoring ground plots with different vegetation cover, humidity and degree of shade. The major aim of the study was to analyze the changes in the species composition and abundance in uropodine (Acari: Parasitiformes) mite communities that occurred in the three ground plots in Jakubowo over 40 years. The second goal was to assess the stability of the species composition and the number of Uropodina mites in the examined communities. The most important phenomenon observed during the research period was a considerable decrease in the abundance of Uropodina in ground litter and soil, and the second was the loss of stenotopic and rare species. Similar observations are also presented in previous studies, which embraced 36 years of research period (between 1978 and 2013). Now, this unfavorable trend, which is caused by anthropogenic disturbances in the environment, has become permanent.

Export and bioaccumulation of methylmercury in streams draining distinct soils in the Central Brazilian Amazon, 2012-2013

BackgroundUpland forest streams of the Central Amazon are unique aquatic systems.These small streams have short, unpredictable and multimodal flood-pulses that are influenced by local rainfall. The biogeochemical cycles in these systems are almost unknown. This study investigated the role of soil type on the export and bioaccumulation of methylmercury (MeHg) in upland forest streams of the Central Amazon during a complete annual cycle. Basic ProceduresLimnological measurements and water samples for MeHg analyses were collected monthly from October 2012 to October 2013 in two headwater streams drained by different soil types, spodzol (Campina Stream) and oxisol (Barro Branco Stream), in natural forest reserves. Shrimp and fish were collected for total mercury (THg) in April 2013 in both streams. Main findingsMeHg in water varied from 0.04 to 0.50 ng/L in the Campina Stream and between <detection limit and 0.04 ng/L in Barro Branco Stream. Physical characteristics of soils and the interaction between mercury and organic matter influenced the methylation of mercury and its export to the streams. In both streams, MeHg export was highest during the rainy season, probably due to soil leaching, lateral flooding and soil hydromorphism during this period, processes conducive to mercury methylation and export. THg in shrimps (omnivores) and carnivorous fish, which fed on aquatic food items, reflected the MeHg differences between streams while those in insectivorous fish, feeding on allochthonous food items, did not. Principal ConclusionsMeHg dynamics in streams were influenced by the physical characteristics of basin soils and by local seasonal rainfall.

SYNOPTIC REVIEW OF FORESTRY AND FOREST PRODUCTS TRADE AND PRODUCTION IN AFRICA

Aims to valuate Africa's forestry and forest products, namely Wood Forest Products (WFPs) and Non-wood Forest Products (NWFPs) in the sixteen (16) West African countries.The study identified a systematic assessment of the most common forest products (wood and non-wood forest products) considering the available data on the national forest reserves of the selected countries in West Africa. The study also revealed the need for biodiversity conservation of the available forest reserves to help mitigate the impact of global warming targeting the United Nation’s Sustainable Development Goal 13- Climate Action. This is focused on integrating climate change mitigation, adaptation, impact reduction, and early warning signs into the national policies, improving forest planning and management education, awareness-raising, and institutional capacity within the sub-region. Keywords: Forestry; Forest Management; Forest Products; Land-Use; West Africa.

Food security and Sustainable Forest Management (SFM) implementation at the Forest Management Unit (FMU) level: A case study in Salarom Taka, Nabawan, Sabah

The forest managed under Sustainable Forest Management (SFM) could contribute to food security, especially for vulnerable communities living in the forest’s vicinity. This study was conducted to determine the local community’s perception of the SFM implementation and food security in Salarom Taka, Nabawan. The interrelation between forest and community’s food security was assessed based on the availability and utilisation of various food resources from four accessible areas: natural forest reserve, forest plantation, alienated land, and resources purchased from the market. The food resources are mainly available and accessible through purchasing, followed by alienated land, forest reserve and forest plantation. Forest contributions are significant, with most communities utilising forest resources for direct food consumption and using fuelwood for food processing. The community depends on the forest to intensify their agricultural production to sustain their food security. The community are less aware of the SFM implementation in their area, but agree with better access to clean water sources, health and education facilities, and more employment opportunities. The roles of forests are strengthened through SFM policy which ensures the forest is managed sustainably, enhancing economic and environmental values that could benefit current and future generations.

Microhabitat, altitude and seasonal influence on the abundance of non-volant small mammals in Mount Rungwe forest nature reserve

A study on microhabitat, altitudinal and seasonal influences on small mammal abundance in Mount Rungwe Nature Forest Reserve, Tanzania was carried out from March 2019 to February 2020 during the wet and dry seasons. Live traps were used in six grids and six transect lines for capturing small mammals at the low, mid, and high elevations (1700–2600 m.a.s.l.). Generalized linear models were used to examine the effects of microhabitat characteristics, altitude, and seasons on the relative abundance of small mammals. A total of 444 rodents and shrews were recorded on 4320 trap nights. Rodent species recorded included Beamys hindei, Cricetomys ansorgei, Dendromus insignis, Grammomys ibeanus, Graphiurus murinus, Lophuromys machangui, Praomys delectorum, and one shrew, Crocidura sp . Overall, P. delectorum was the most dominant species in all elevations, with 68.9% of all captures. Mid elevation had a higher abundance of small mammals (Estimate ± SE = 1.17 ± 0.49, Z = 2.37, p = 0.0176). Species abundance was influenced differently by elevation. While P. delectorum decreases with increasing elevation, L. machangui increases with an increase in elevation. Although overall small mammal abundance was not affected by microhabitat variables (Estimate ± SE = −0.08 ± 0.13, Z = −0.67, p = 0.5050), individual species ( P. delectorum and L. machangui ; Estimate ± SE = 0.13 ± 0.06, Z = 1.95, p = 0.05 and −0.31 ± 0.09, Z = 3.34, p = 0.0008 respectively) were affected differently. While P. delectorum abundance showed a positive correlation and increased with an increase in PCA1 in GLM, L. machangui had a negative trend that shows they were affected differently. Small mammal abundance, on the other hand, was affected by season and, in particular, rain, with low abundance during heavy rains and dry cold periods (Estimate ± SE = 0.51 ± 0.14, Z = 3.6, p = 0.0003 and 0.3 ± 0.15, Z = 2.08 p = 0.04 respectively). In general, the results show that microhabitat parameters, elevation, and season influenced small mammals’ abundance in MRFNR. This outcome indicates that altering the microhabitat could have an impact on the small mammal assemblage and particularly their abundance. Thus, microhabitat, elevation, and season influence small mammal abundance and can be used as a proxy for evaluating the biodiversity of montane tropical small mammal communities.

Functional Diversity of Plant Communities in Relationship to Leaf and Soil Stoichiometry in Karst Areas of Southwest China

Assessment of relationships between functional diversity and ecological stoichiometry in plant communities can aid in determining the relative variability and ecological complementarity of functional attributes among species, which is a better approach to understanding ecosystem processes and functions than studying species taxonomic diversity. Here, we analyzed the relationships among community weighted means of functional traits, functional diversity, and leaf and soil chemical properties of plant communities during various stages of vegetation restoration in Mao Lan National Karst Forest Nature Reserve, located in humid subtropical Guizhou of China. Our results showed significant changes in four weighted functional traits of plant communities at different restoration stages, namely, plant height, leaf width to leaf length ratio, and leaf area. Additionally, with the progression of the recovery of plant communities, functional richness, functional separation, and quadratic entropy, the coefficient tended to increase. Functional divergence tended to gradually decrease. The association of functional diversity with soil chemical properties was stronger than that with leaf ecological stoichiometry. Regarding leaf and soil chemical properties, soil phosphorus content and leaf C:P were particularly important in influencing functional diversity. Our overall findings indicate that functional traits shift from “acquisitive” to “conservative” as the community is restored. Karst plant communities reduce interspecific resource competition as restoration proceeds, thereby increasing functional overlap effects.

Ichthyofaunal diversity in the upper Jejuí River watershed in eastern Paraguay

ABSTRACT The upper Jejuí River is a major tributary of the Paraguay River in eastern Paraguay and is the principal drainage for the Mbaracayú Forest Biosphere Reserve. Despite the international significance of the biosphere reserve and detailed documentation of its terrestrial fauna and flora, the fish fauna in its streams remains relatively unknown, with 48 species previously recorded. We sampled 35 sites within the biosphere reserve over five years (2007–2011) to assess the richness of its ichthyofauna. These surveys yielded a new total of 105 known species for the biosphere reserve, including two newly-recorded orders, Gymnotiformes and Cyprinodontiformes, and 14 newly-recorded families. Fish community composition resembled that of previously-reported fish communities from the Paraguay River drainage, with characiforms and siluriforms comprising the majority of the species (57.1% and 31.4%, respectively). Post hoc analyses showed significantly greater ichthyofaunal diversity at sites within the Mbaracayú Forest Nature Reserve, a core protected forest area within the biosphere reserve, compared to areas outside the nature reserve, suggesting a negative impact from deforestation and land conversion on fish assemblages in these headwater streams. Broad regional deforestation places greater emphasis on important management decisions that will protect current biodiversity.

Особенности горизонтальной структуры лесов еловых формаций европейской тайги России

The article highlights the issues of studying the structure of indigenous forests of different ages as a model of sustainable forest formations. The research purpose is to study the patterns of horizontal structure formation of indigenous virgin spruce forests of the northern, middle and southern taiga subzones of European Russia. We consider the nature of the horizontal structure as one of the most important signs of sustainability of forest communities developed over the evolution. Indigenous virgin spruce forests in each of the taiga subzones of European Russia were adopted as research objects: spruce forests of the Severodvinsk forestry of the Arkhangelsk region in the northern taiga subzone; spruce forests of the Vepsky forest reserve in the middle taiga subzone; spruce forests of the Central Forest Nature Reserve in the southern taiga subzone. Sample plots were laid out in biogeocenoses, where we studied the age, horizontal, and pathological characteristics of spruce forests. Continuous tree drilling was carried out to determine the age of trees and their infestation by wood-destroying fungi of the biotrophic complex. The mosaics of age generations were identified on the plans of sample plots; the area of each of them, the volume of trees in the mosaics and the homogeneity by age, and the amount of natural regeneration were determined. Indigenous spruce fir forests of the taiga of European Russia have a different age structure with a different number of age generations in the age series and various dynamic indicators of biogeocenoses. All of them have a mosaic arrangement of trees grouped by different age generations, growing in different sized areas and distinguished by an unequal degree of homogeneity in terms of age. This defines a complex age horizontal and vertical structure of biogeocenoses; the most important condition for sustainability of forest communities. Accounting of spruce natural regeneration showed significant differences in the number of undergrowth in spruce forests of different taiga subzones, which refers to a variety of horizontal structures of such forests. The ratio of the number of spruce undergrowth growing on decaying trunks of woody debris and on the ground is as follows: the number of 0.5 m high undergrowth in both growing conditions is almost equal, the number of over 3 m high undergrowth on deadwood trunks is less compared to the number of undergrowth of this height category on the ground.

Effectiveness of functional zones in National Nature Reserves for the protection of forest ecosystems in China

Protected areas (PAs) have been established worldwide to conserve biodiversity. However, the conservation effectiveness of different PA functional zones remains poorly understood. Here, we investigated National Nature Reserves (NNRs) in China to explore and quantify the conservation in their core, buffer, and experimental zones. We compared the area and proportion of forest loss for these functional zones during the period from 2001 to 2018. The results showed that the forest loss in NNRs showed a decreasing trend since 2011, indicating that NNRs reduced the forest loss. There was no significant difference of forest loss proportion (p = 0.42) between the core zones (0.60 ± 1.32%) and buffer zones (0.55 ± 0.88%), implying that their performance in forest conservation was similar. There was a significant difference between experimental and core zones as well as between experimental and buffer zones both in forest loss area and proportion (p ˂ 0.05). We confirmed that the proportion of functional zones significantly affects the conservation effectiveness, i.e., an improper proportion of core zones or buffer zones may lead to forest loss. Therefore, we suggest an optimal proportion of core and buffer zones at 30%–50% and 10%–40%, respectively. Overall, the effectiveness of functional zones in forest nature reserves was assessed on a national scale. The results of this study support the recent adjustment in the PA functional zoning system in China.

Rare Earth Elements in Soils of the Central Forest State Nature Biosphere Reserve

The total content of rare earth elements (REEs) and the content of their oxalate-soluble fraction were studied in four soil profiles (Gleyic Umbrisols, Albic Gleyic Folic Retisols (Raptic), Dystric Albic Retisol) of the Central Forest Nature Reserve. The REE content was normalized to a local standard (the Russian Platform clay), and the cerium and europium anomalies were quantified [8]. In addition to the initial redistribution of REEs during the formation of rocks, REEs in the studied soils undergo geochemical fractionation, which results in the depletion of soil horizons of heavy lanthanides and europium. The negative europium anomaly is maximal in eluvial horizons and is weaker or absent in organic horizons. The oxalate-soluble REE fraction affects the redistribution of heavy lanthanides and cerium in the studied soils, and also results in the development of a positive cerium anomaly in some horizons.

Have China's national forest reserves designated since 1990 conserved forests effectively?

China's forests were severely degraded by human activities during the latter half of the 20th century. Therefore, China enacted ambitious programs of natural forest protection and afforestation to protect and expand forests. Yet it is unclear how the programs, especially the designation of forest reserves, have affected forest cover and fragmentation. We evaluated the effectiveness of China's national forest reserves designated since 1990 in conserving forests, by analyzing four forest metrics (i.e., percentage forest cover, mean forest patch size, mean forest patch radius of gyration, and forest patch cohesion index) derived from a newly produced 30 m annual China land cover dataset from 1990 to 2019. We found that overall forest cover increased and fragmentation decreased from baseline years, when reserves were designated, to 2019 in both reserves and their surrounding areas, and only the increase in forest cover relative to baseline was significantly greater in reserves than in surrounding areas. The designation time of reserves under national protection had no considerable effect on changes in the four metrics, but for zonation, the core zone showed a significantly higher increase in forest patch cohesion index relative to baseline than the buffer and transition zones. Nevertheless, forest cover declined and fragmentation increased in highly forested reserves, suggesting destructive human activities and ineffective management. Thus, forest protection and regeneration programs were moderately successful. We recommend that there is significant improvement needed to ensure greater protection of existing forests and reduction of threats to promote effective management.

Indigenous knowledge and utilization of wild Mushrooms in communities around Kibira and Bururi mountain forests in Burundi

Wild mushrooms are of paramount importance to human beings as a source of food, income and medicinal applications. However, the ethnomycological knowledge has not been well documented in Burundi and the potential benefits of this knowledge in medicine and sociocultural fields have not been explored. This study explored and documented the indigenous knowledge of wild edible mushrooms from the communities living around the Kibira and Bururi mountain forests in Burundi for the first time. Field surveys were conducted in the communities living around the Kibira National Park and the Bururi Forest Nature Reserve to document the local knowledge and the use of wild mushrooms. The interviews involved randomly picked 160 respondents of which, 99.4% of interviewees affirmed knowing mushrooms and 97.5% already utilized mushrooms. Among these, 69.4% utilized them as food. They recognize mushrooms as an alternative source of income (21.9%) and their medicinal applications (6.2%). The knowledge of mushroom edibility is transferred from parents to children by oral inheritance. That method has a negative impact on the traditional dissemination of this knowledge in the future due to some beliefs and conservative eating habits that induce a certain fear of mushrooms known as mycophobia, leading to the rejection of several mushroom species despite belonging to recognized edible taxa. A traditional method referred to as "Gusabura" was reported for eliminating toxic compounds in mildly toxic mushrooms prior to their consumption. The ethnomycological knowledge in Burundi is at risk of disappearing. Hence, there is a need to preserve this valuable indigenous knowledge by properly documenting it and introducing it in the lower level of the education system.

Inter- and Intraspecific Differences in Physical and Mechanical Properties of Wood from Sclerocarya birrea and Anogeissus leiocarpus

This paper studied the basic density and mechanical properties differences of wood among and within Sclerocarya birrea and Anogeissus leiocarpus. Three trees from each species were selected from the Lagawa Natural Forest Reserve in Western Kordofan State, Sudan. Test specimens were selected from three vertical positions (10, 50, and 90% along the bole length) of the trees. Specimens were also collected from three horizontal positions (innerwood, middlewood, and outerwood) within each of the three vertical positions. Tests for basic density of wood (BD), modulus of rupture (MOR), modulus of elasticity (MOE), compressive (CS), and shear strength (SS) parallel to the grain were performed. An analysis of variance shows that only the horizontal positions were a significant source of variation for both species studied. The correlation coefficient of BD was significant, weak, and positive for the mechanical properties of A. leiocarpus. A similar observation was found for BD correlated with CS and SS for S. birrea.

土壤湿度对中国南部热带森林土壤甲烷吸收的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 土壤湿度对中国南部热带森林土壤甲烷吸收的影响 DOI: 10.5846/stxb202106281706 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 海南省自然科学基金高层次人才项目（421RC668） Effects of soil moisture on methane uptake in a tropical forest of southern China Author: Affiliation: Fund Project: Natural Science Foundation of Hainan Province 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:森林土壤是一个重要的大气甲烷的汇。然而，相较于寒带和温带，在热带尤其是东南亚地区，森林土壤甲烷通量的观测较少，这限制了目前对热带森林土壤甲烷通量与环境因子之间关系的认识，也给热带森林土壤甲烷汇的估算带来了一定的不确定性。在中国海南省吊罗山国家森林公园的热带森林土壤，采用激光光谱法测量了2016年9月至2018年9月逐月的土壤甲烷通量，并分析了其与周围环境因子的关系。结果表明：研究区土壤是甲烷的汇，山顶样地的年平均吸收量为0.95 kg CH4-C hm-2 a-1，山脚样地的年平均吸收量为1.93 kg CH4-C hm-2 a-1。干季（11月-次年4月）的甲烷吸收通量明显高于湿季（5-10月），占到全年甲烷吸收的68%。山顶样地年平均土壤湿度为19.2%，年内的波动较小（2.8%）。而山脚样地的年平均湿度相对较低，为12.7%，且年内波动大（5.4%）。土壤湿度是控制甲烷吸收最主要的环境因子，可以解释月际甲烷吸收变化的76%，甲烷吸收通量与土壤温度的相关性则不显著。当土壤湿度高于20%（体积分数）时，研究区土壤开始从甲烷的汇转变为甲烷的源。综合研究及热带其他研究中甲烷吸收与土壤湿度的关系，推算出热带森林土壤的甲烷年吸收量为1.72 Tg CH4-C/a。结果对东南亚地区长时间甲烷通量观测及热带森林土壤甲烷汇的估算具有重要意义。 Abstract:Forest soils contribute substantially to the global methane uptake. However, compared with the cold and temperate zones, measurements of methane flux from the soils in the tropical forests are still sparse, especially in Southeastern Asia. This gap limits our understanding of the relationship between the methane flux from the soils and the environmental factors, which leads to large uncertainty in the estimation of the methane uptake flux from the tropical forest soils. This study was conducted in Diaoluoshan National Forest Reserve in Hainan Province, China. We measured monthly methane flux from the tropical forest soils by near-infrared laser greenhouse analyzers from September 2016 to September 2018. Soil moisture and soil temperature were measured simultaneously by Decagon 5 TM sensors. Furthermore, we analyzed the relationship between the methane flux with the environmental factors. The results revealed that the soils of the study area served as the sink of atmospheric methane during a 2-year period. The methane uptake in tropical forest soils at the top of the mountain was 0.95 kg CH4-C hm-2 a-1, while that in tropical forest soils at the foot of the mountain was 1.93 kg CH4-C hm-2 a-1. The methane uptake flux in the dry season (from November to April next year) was significantly higher than that in the wet season (from May to October). The former one accounted for about 68% of the methane uptake flux of the whole year. The mean annual soil moisture at the top of the mountain was 19.2% with an intra-annual variance of 2.8%. And the mean annual soil moisture at the foot of the mountain was 12.7% with a bigger intra-annual variance (5.4%) than that at the top of the mountain. Soil moisture acted as the significant predictor of the methane uptake flux and accounted for 76% of the variance. There was no significant correlation between methane uptake flux and soil temperature. For soil moisture lower than 20% (v/v), the relation between soil moisture and methane flux was best fitted with linear regression. For soil moisture higher than 20% (v/v), the tropical forest soils of the study area turned from the sink to the source of the methane flux. According to the relationship between soil moisture and methane flux in the tropical forests, we estimated the annual methane uptake of the tropical forest soils was 1.72 Tg CH4-C/a. Our results have important implications for long-term methane flux measurements in Southeastern Asia and the estimation of the magnitude of the methane uptake from tropical forest soils. 参考文献 相似文献 引证文献

The most dangerous invasive plant in Protected Areas of the Mountain Crimea

Due to the spur increase in the number and scale of invasions over the past few decades, the study of this problem has become a matter of environmental and economic security in many countries, including Russia and the territory of the Crimea. The Crimean Peninsula, located in the south of Eastern Europe, is one of the centers of plant diversity. Special attention should be paid to invasive species that can actively introduce themselves into both anthropogenic and natural phytocenoses. The article deals with the problem of introduction of invasive species to the Protected Areas of the Mountainous Crimea: Yalta Mountain Forest Nature Reserve, Nacional Park “Krymsky”, Karadagsky Nature Reserve and Nature Park “Cape Martyan”. The most common and dangerous species for the ecosystems of the Protected Areas were identified ( Ailanthus altissima, Berberis aquifolium, Bupleurum fruticosum, Clematis flammula, Daphne laureola, Fraxinus ornus, Jacobae maritima, Opuntia humifusa, O. engelmannii var. lindheimeri, O. phaeacantha, Quercus ilex, Rhamnus alaternus ) on the based of floristic, phytocenotic and other studies. A comprehensive analysis of the current state was carried out and new data were obtained on the distribution, phytocenotic, biotopic allocation and other features of these species in the conditions of the native and outside its native distributional. It was found that invasive species that pose a threat to the ecosystems of four Protected Areas of the Mountainous Crimea were found in different types of biotopes belonging to 4 groups and 16 subgroups identified according to the EUNIS classification of biotopes: coastal marine (B1.33, B2.13, B3.1, B3.3324); herbaceous communities (E1.3, E1.33, E1. 4); tree and shrub communities of temperate and Mediterranean regions (F3.246, F5.16, F5.3, F6.8), forest communities (G1.22, G1.7, G2.2, G3.5, G4.B). These species grow in communities belonging to 10 classes, allocated according to the ecological and floral classification of Braun-Blanquet: Asplenietea trichomanis, Carpino-Fagetea sylvaticae, Crithmo-Staticetea, Cymbalario-Parietarietea diffusae, Drypidetea spinosae, Erico-Pinetea, Lygeo sparti-Stipetea tenacissimae, Ononido-Rosmarinetea, Pegano harmalae-Salsoletea vermiculatae, Quercetea pubescentis . The most invasive are the communities of unions Jasmino fruticantis-Juniperion excelsae, Elytrigio nodosae-Quercion pubescentis (class Quercetea pubescentis ), Elytrigio bessarabicae-Lactucion tataricae (class Crithmo-Staticetea ).

Vascular plant occurrences in grasslands of Central Forest Nature Reserve (Russia): a dataset.

BackgroundHere we present the sampling event dataset that contributes to studying the flora of grasslands in Central Forest State Nature Biosphere Reserve (part of the UNESCO World Network of Biosphere Reserves), Tver Oblast, Russia. The Reserve is located in the SW part of the Valdai Upland within the main Caspian-Baltic watershed of the Russian plain (Latitude: 56° 26' – 56° 39' N, Longitude: 32° 29' – 33° 01' E). The territory of Central Forest Reserve belongs to the subzone of subtaiga.New informationThe dataset includes the occurrences of vascular plant species in four types of grasslands from 209 vegetation plots (8,506 associated occurrences), collected in 2013-2014. The dataset described in this paper has never been published before.As the grasslands in Central Forest State Nature Biosphere Reserve are relatively unstudied, we are providing a new comprehensive dataset on the vascular plant species occurrences in the grasslands of the Reserve. The dataset contains representative information on floristic composition of plant communities in localities with assigned GPS coordinates. As the vegetation of the Reserve is typical of the subtaiga subzone, the results of analysing this dataset can be useful for grassland management in the whole subtaiga subzone.During this study, we found one vascular plant species included in the Red Data Book of the Russian Federation, three species from the Red Data Book of Tver Oblast, as well as 10 alien vascular plant species for the Reserve. These data, especially, the occurrences of protected and alien species, contribute to our knowledge of species composition of the grasslands of the Reserve.