Forestry Studies最新文献

{"title":"Effect of sample plot size and shape on estimates of structural indices: A case study in mature silver birch (Betula pendula Roth) dominating stand in Järvselja","authors":"Kobra Maleki, A. Kiviste","doi":"10.1515/fsmu-2015-0013","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0013","url":null,"abstract":"Abstract Structural indices and characteristics have often been employed for assessing different aspects of forest stands. In order to assess the performance of such measures in forest sample plots of different size and shape, the current study is based on a data set for a relatively large (1 ha) silver birch dominated stand, and five simulated planar point patterns (a Poisson process, two clustered and two regular patterns) with similar intensity of points distributed on an area equal to the silver birch stand as reference stands. The analyses was based on repeated samplings of the stands, with randomly placed circular or square shaped plots of different sizes, with area ranging from 0.007 to 0.636 ha. Similar centre positions were considered for plots of different shapes, but the locations of the plot centres differed with size, so that plots of different sizes were able to cover the maximum possible area of reference stands. Some structural indices accounting for one or four nearest neighbours, and also the Point-pair correlation function was then quantified for each random sample plot. We used standard deviation and the differences of the mean estimates from the expected values to assess the sensitivity of the structural measures to the size and shape of sampling plots. The results indicated the significant effect of plot size and shape on structural indices. The correlation between plot size and estimates precision was positive, and small plots, regardless of their shapes, showed big variation among them while circular plots often provided more accurate estimates. Even though, as expected, expanding the plots increased the precision of the neighbourhood-based indices’ estimates (spatial measures), and also resulted in inaccurate estimates for some reference stands, depending on the arrangement of trees/points within that stand.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"74 6 1","pages":"130 - 150"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89205211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valuation of timber production and carbon sequestration on Järvselja nature protection area","authors":"V. Adermann, A. Padari, R. Sirgmets, A. Kosk, P. Kaimre","doi":"10.1515/fsmu-2015-0007","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0007","url":null,"abstract":"Abstract Järvselja nature protection area was established in order to preserve and introduce virgin forests, to protect old natural forests, old deciduous forests and habitats of different species. At the same time the stands of nature protection area provide other benefits having both use and non-use values. The goal of the study is to assess the monetary value of the two components of forest ecosystem: timber production and carbon sequestration. The value of timber expresses to forest owners and policy-makers the opportunity cost of nature protection. The carbon sequestration represents the value of new service, highly appreciated in the context of climate policy. While a market for timber and carbon exists, the market-price method has been used for valuation. The data for calculations was obtained from the materials of forest inventory carried out in 2010 by the Department of Forest Management, Estonian University of Life Sciences. According to the calculations the theoretical long-term average value of timber is 325 euros per hectare. The monetary value of timber production is approximately three times higher compared to average productivity of Estonian private forests. The guidelines of Intergovernmental Panel on Climate Change for the inventories of greenhouse gases were used when transforming the growing stock and dead stem timber into biomass and finally into carbon and carbon dioxide. According to the price 4.62 € per ton of tradeable carbon equivalent in autumn 2013, the value of carbon sequestration on Järvselja nature protection area could be estimated 1473 € per hectare of forest land. Because of the high age of stands on nature protection area, the role of forests as a sequestrator of CO2 is remarkable compared to commercial forests. The accumulation of carbon in old-growth natural forests is close to zero, but they still fulfil the role of being a carbon pool.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"16 1","pages":"29 - 43"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85527237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About evaluation of vegetation changes on permanent sample areas in Järvselja protected compartment","authors":"J. Paal, Kristiina Jürisoo, T. Paál","doi":"10.1515/FSMU-2015-0006","DOIUrl":"https://doi.org/10.1515/FSMU-2015-0006","url":null,"abstract":"Abstract The changes in tree layer saplings, shrub, field and moss layer in Järvselja Nature Reserve virgin forest compartment (JS226) were analysed on the ground of data collected in 1955, 1985, 1993 and 2012. Four forest stands (sub-compartments) were studied; in every stand one 4 × 4 m sample area was established: area A1 represented Hepatica nobilis and Anemone nemoralis dominanted spruce stand, area A3 – drained transitional mire pine forest, area A4 – Mercurialis perennis-rich spruce stand and area A5 – Hepatica nobilis and Anemone nemoralis dominanted aspen stand. The number of tree layer saplings and shrub layer stems, as well as their species content have changed largely in all sample areas, being a bit more stable only on area A1. In field layer the abundance of initial dominant species changed remarkably in all areas or were replaced by other species in the course of succession. Changes in moss layer were the most striking in drained transition mire forest (area A3), where Pleurozium schreberi, Sphagnum centrale and S. capillifolium dominating in 1955 were replaced by S. centrale in 1993. The experiment planning in the current study is regrettably insufficient: to study forest communities succession using only one 4 × 4 m sample area in every stand does not allow to gather representative data about the vegetation structure and its variation limits. Moreover, in that way it is not possible to separate the time-induced successional trend from the drainage impact that has an obviously prevailing importance in forest compartment JS226 being surrounded by ditches.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"09 1","pages":"28 - 5"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86046356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tree stems from terrestrial laser scanner measurements","authors":"A. Kuusk, Mait Lang, Silja Märdla, J. Pisek","doi":"10.1515/fsmu-2015-0008","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0008","url":null,"abstract":"Abstract Terrestrial laser scanner (TLS) measurements were carried out in mature birch, pine, and spruce stands in Järvselja, Estonia. The structure of stands has been previously studied. A simple special clustering procedure is developed for automatic detection of stem positions and estimation of tree stem dimensions from the TLS point cloud. Tree stem diameter at breast height (DBH), vertical profile of stem and size distribution of DBH is estimated with high precision in the pine stand where the second growth tree layer is almost missing. The presence of second growth limits estimating stem dimensions accurately in the birch stand, and the procedure fails in the dense spruce stand of rich undergrowth and low dead branches. In such stands the TLS measurements should be done in dense grid with short-range sounding setup only. The developed procedure is undemanding for computers and can be applied on simple PC-s.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"3 1","pages":"44 - 55"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87816128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recreational activities impact on the amount and characteristics of woody debris in the Fandoghlou forests, Northwestern Iran","authors":"F. Behjou, K. Sefidi","doi":"10.1515/fsmu-2015-0001","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0001","url":null,"abstract":"Abstract In this research, the volume and composition of woody debris (WD) were inventoried by line intersect sampling (LIS) in recreational and conservative parts of Fandoughlou forests in Northwestern Iran. Based on the pre-study qualitative assessments of WD properties, 60 transects in conserved part including 60 ha tract and 60 transects in recreational part including 60 ha and 60 transects were set up for WD survey. In each area, a systematic series of sampling points was located in the inventory of WD. At each sampling point, we performed line-intersect sampling (LIS) with a line length of 100 m with random orientation of sample lines. Estimates of the total volume of WD across recreational and conservative parts of the forest ranged from 0.70 m3 ha-1 to 1.49 m3 ha-1. The results of independent t-test indicated that the amount of CWD and FWD in conserved part is significantly higher than CWD and FWD in recreational part (t4, 0.05 = 4.26, p = 0.013; t4, 0.05 = 2.69, p = 0.05). The number of tree species of CWD composition was higher in conserved area, more than 5 species including (hazel, beech, hornbeam, oak, maple, and other species). In the conserved part, CWD in highly-decayed classes accounted for 75% of total CWD volumes, but in the recreational division, CWD in the early decayed classes accounted for 79% of total WD volumes. Our results suggest preserving the current conserved forests and maintaining the structural and functional integrity of WD.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"35 1","pages":"13 - 5"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80058103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon sequestration potential of nitrogen-fixing tree stands","authors":"M. Sheikh, Munesh Kumar, N. Todaria","doi":"10.1515/fsmu-2015-0004","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0004","url":null,"abstract":"Abstract We compared the C storage of two nitrogen-fixing trees in mixed and monospecific plantations to investigate the C sequestration potential after 10 years of their establishment. The study was carried out in three types of plantation, Dalbergia sissoo Roxb. ex DC. pure (P1DS), Leucaena leucocephala (Lam.) de Wit pure (P2LL) and mixed plantation of D. sissoo and L. leucocephala (P3DS.LL). The results of the study indicated that, P3DS.LL sequestered 34.30 ± 0.24 t yr-1 ha-1 CO2 compared to 27.35 ± 0.19 t yr-1 ha-1 in P1DS and 19.81 ± 0.44 t yr-1 ha-1 in P2LL. Total carbon storage was also maximum in P3DS.LL (93.47 ± 0.67 t ha-1) followed by P1DS (74.54 ± 0.53 t ha-1) and P2LL (53.98 ± 1.21 t ha-1). This indicates that L. leucocephala has synergetic effect with D. sissoo to enhance the carbon sequestration potential when interplanted together. The study revealed that mixed plantation of N-fixer trees have potential to sequester more carbon than same species in monoculture. The study concluded that in reforestation or afforestation program the synergic effect of N-fixer trees can be helpful projects to offset more C emissions.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"64 1","pages":"39 - 47"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81446970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring and modeling of forest ecosystems: the Estonian Network of Forest Research Plots / Metsaökosüsteemide seire ja modelleerimine metsa kasvukäigu püsiproovitükkide võrgustiku abil","authors":"A. Kiviste, M. Hordo, A. Kangur, A. Kardakov, D. Laarmann, Ando Lilleleht, Sandra Metslaid, A. Sims, H. Korjus","doi":"10.1515/fsmu-2015-0003","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0003","url":null,"abstract":"Abstract Forest research has long traditions in Estonia that can be traced back to the 19th century. Data from long-term forest experiments are available since 1921. The first studies mainly focused on silvicultural treatments and application of such data for understanding and modeling ecological processes was limited. The Department of Forest Management of the Estonian University of Life Sciences started to develop the Estonian Network of Forest Research Plots (ENFRP) in 1995. Since then, plots have been continuously re-measured with 5-year interval. Approximately 100-150 permanent sample plots were measured annually. In 2014, the long-term research network consisted of 729 permanent sample plots, of which 699 have been re-measured at least once, 667 plots - twice and 367 plots - three times. The total number of trees recorded in the network database amounts to 130,479. The plots are systematically distributed throughout the country. Detailed dendrometric measurements including tree spatial distribution are part of the survey protocol. Initially the network was set up to produce suitable data for development of individual tree growth models for Estonia. The significance of the network for the Estonian forest research is continuously increasing and nowadays ENFRP is recognized as an important national research infrastructure.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"49 1","pages":"26 - 38"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91259752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wood color analysis and integrated selection of Paulownia clones grown in Hubei Province, China","authors":"Lingjun Cui, Baoping Wang, Jiejuan Qiao, Jianguo Zhang","doi":"10.1515/fsmu-2015-0005","DOIUrl":"https://doi.org/10.1515/fsmu-2015-0005","url":null,"abstract":"Abstract Paulownia Siebold et Zucc., a widely distributed native genus, has been commonly used in the furniture. The color of wood is a very important aesthetical property, and it has a fundamental influence on the commercial value of timbers. Therefore, it is critical for forest managers to select elite Paulownia clones based on the color of wood. Eighteen 5-year-old Paulownia clones grown in a hilly area in Hubei Province, China were examined in terms of color values (L*, a*, b*), color difference (ΔE*), and Hunter lab space whiteness (W) using a Chroma meter CR-400. Differences in color parameters among the 18 clones were analyzed and clustered. The results showed that the ranges of L*, a*, b*, ΔE*, and W were 77.19-80.38, 3.60-4.84, 13.79-15.69, 17.92-21.37, and 68.92-72.42, respectively. The color parameters significantly differed among the examined clones. Differential and cluster analyses indicated that clones 204, 605, 702, and 603 had higher L*, W, and lower ΔE*, rendering these as elite clones with superior color properties.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"12 1","pages":"48 - 57"},"PeriodicalIF":0.0,"publicationDate":"2015-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82392043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photographic assessment of overstory and understory leaf area index in beech forests under different management regimes in Central Italy","authors":"F. Chianucci, N. Puletti, Ernesto Venturi, A. Cutini, U. Chiavetta","doi":"10.2478/fsmu-2014-0008","DOIUrl":"https://doi.org/10.2478/fsmu-2014-0008","url":null,"abstract":"Abstract. Forest understory may be strongly affected by silvicultural practices such as thinning, which simultaneously modulates the overstory canopy cover and influences the availability of light. However, the understory layer is rarely considered in management decisions, partly because methods to estimate understory leaf area index are poorly developed. In this study we used two different restricted view angle photographic methods to estimate overstory plant area index LO (zenith cover photography), understory leaf area index LU (nadir cover photography) and their related canopy attributes (foliage clumping, foliage cover, crown cover, crown porosity). These measurements were performed in beech stands under different management regime. Results from photography indicated that not only overstory but also understory canopy attributes were significantly influenced by forest management. In addition, a significant negative correlation was found between LO and LU. We conclude that the photographic methods are effective for monitoring (overstory and understory) canopy status in managed stands, on account of their rapid and not destructive procedures, which allows large scale implementation of the methods.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"75 1","pages":"27 - 34"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83455065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of standing wood volume and species composition in managed nemoral multi-layer mixed forests by using nearest neighbour classifier, multispectral satellite images and airborne lidar data / Puistute liigilise koosseisu ja tüvemahu hindamine k-lähima naabri meetodil mitmerindelistes majanda","authors":"Mait Lang, T. Arumäe, T. Lükk, A. Sims","doi":"10.2478/fsmu-2014-0010","DOIUrl":"https://doi.org/10.2478/fsmu-2014-0010","url":null,"abstract":"Abstract. Nearest neighbour techniques are useful for constructing maps of forest inventory variables based on sample plot and auxiliary data from remote sensing. The most problematic issue of the nearest neighbour technique is possible systematic bias in the estimated values. In this study a 15 by 15 km test site in nemoral multilayer mixed forests was established in Laeva, Estonia. A set of 444 circular sample plots was used as reference set. Airborne lidar data and Landsat-8 Operational Land Imager image were used to construct five different feature variable sets consisting of original variables and alternatively principal components. The response variables were wood volume of first tree layer, wood volume of the second tree layer and main species code. A special test was carried out where a substantial amount of Silver birch dominated plots were removed from the reference set. The wood volume prediction validation was carried out on 89 forest growth sample plots and on 2290 forest stands. Species composition prediction was validated on 986 forest stands. As in many previous studies the results confirmed superiority of airborne lidar variables over spectral variables for wood volume estimation. The first three principal components of airborne lidar variables and first five principal components of all possible original feature variables contained over 99% of the information and performed well in imputations. The imputed wood volume at small values was overestimated and underestimated at large values regardless of used reference set. The feature variable sets containing spectral data performed better for species composition imputation. There was a forest age dependent discrepancy in predicted species proportions: birch and spruce proportions were underestimated in young stands and overestimated in older stands while proportion of aspen had exactly the opposite errors. The lack of fit depended slightly on the feature variable sets. The birch dominated plot partial removal from the reference set changed the predicted proportion of species but did not remove the forest age dependent lack of fit. The result can be important for the studies in which bootstrap samples are used to estimate error statistics for nearest neighbour technique based forest inventory variable maps.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":"44 1","pages":"47 - 68"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74140545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}