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Strimbu B.M.,Louisiana Tech University | Strimbu B.M.,Forest Research and Management Institute
Forestry | Year: 2014

Forest resources can be assessed using two ground measurements approaches: one centred on preset intensity and the other centred on sampling error. The objective of the present research is to evaluate the efficiency of the two sampling approaches using a factorial design, the factors being intensity, area, sampling error and coefficient of variation. Overall, an inventory executed using sampling error is likely more efficient than using a preset intensity (i.e. 89 per cent of the investigated cases). For small tracts (i.e. =5 ha) or tracts with one stratum, forest inventories using preset intensities are more efficient, but mainly for reduced intensities (i.e. 5 per cent). For larger tracts and moderate variability (i.e. coefficient of variation =30 per cent), resource estimation based on sampling error is more efficient than the intensity-based, especially when the tract is stratified. Stratified random sampling inventories are almostalwaysmoreefficient than10percent intensity cruises, and, in90percent of the cases,5per cent cruises. For balanced strata, the efficiency is so large that tracts with same size but different variability are indistinguishable, from sampling efficiency perspective. Therefore, a preliminary cruise can focus on attributes that are not the objective of the inventory but are related to the attributes of interest, easy, fast and accurate to measure, such as diameter at breast height, basal area or tree height. © Institute of Chartered Foresters, 2013. Source

Filat M.,Forest Research and Management Institute
Annals of Forest Research | Year: 2010

Poplar and willows are the main fast growing tree species used for biomass production in short rotation coppiced (SRC) cultures. The main characteristics for biomass production (plant survival, basal diameter and height increment) after first growing season are presented. Four Italian clones - AF2, AF6, AF8 and Monviso (Alasia New Clones) and two controls - Turcoaia and Sacrǎu 79' (ICAS, România) have been tested in five experimental cultures, in different locations. Italian energetic clones have adapted very well to the pedoclimatic conditions of South-Eastern Romania, being more competitive than control clones in terms of biomass production and resistance to leaf diseases. AF8 and Monviso have registered the most active growth. Source

Sofletea N.,Transilvania University of Brasov | Budeanu M.,Forest Research and Management Institute | Parnuta G.,Forest Research and Management Institute Bucharest
Silvae Genetica | Year: 2012

The performance of 33 Norway spruce [Picea abies (L.) Karst.] seed sources from the Romanian Carpathians was evaluated with respect to growth and wood characteristics in comparative trials located at two different site conditions: Avrig- outside of the natural range of Norway spruce and Breţcu - within the natural range of this species. The radial increment (RI), latewood percentage (LWP) and conventional wood density (CWD) traits were evaluated at age 30 years after plantation. Phenotypic correlations between the evaluated traits, on the one hand, and between the same traits and the geographic gradients of the origin of seed sources, on the other hand, were calculated. Analysis of variance showed significant (p<0.01) differences between seed sources for RI, while for LWP and CWD, the differences were highly significant (p<0.001). These results suggest that selection at seed sources level could be possible. The test sites influence the LWP and CWD, while the RI is almost similar in both sites. For RI, the most valuable populations are situated in the Eastern and Western Romanian Carpathians. The highest LWP was registered for the Eastern Carpathian populations, while the lowest was recorded for the Western Carpathian populations. The Southern Carpathian populations, characterized by a lower growth rate, had higher values for wood density. Source

Strimbu V.F.,Norwegian University of Live science | Strimbu B.M.,Louisiana Tech University | Strimbu B.M.,Forest Research and Management Institute
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2015

This work proposes a segmentation method that isolates individual tree crowns using airborne LiDAR data. The proposed approach captures the topological structure of the forest in hierarchical data structures, quantifies topological relationships of tree crown components in a weighted graph, and finally partitions the graph to separate individual tree crowns. This novel bottom-up segmentation strategy is based on several quantifiable cohesion criteria that act as a measure of belief on weather two crown components belong to the same tree. An added flexibility is provided by a set of weights that balance the contribution of each criterion, thus effectively allowing the algorithm to adjust to different forest structures.The LiDAR data used for testing was acquired in Louisiana, inside the Clear Creek Wildlife management area with a RIEGL LMS-Q680i airborne laser scanner. Three 1ha forest areas of different conditions and increasing complexity were segmented and assessed in terms of an accuracy index (AI) accounting for both omission and commission. The three areas were segmented under optimum parameterization with an AI of 98.98%, 92.25% and 74.75% respectively, revealing the excellent potential of the algorithm. When segmentation parameters are optimized locally using plot references the AI drops to 98.23%, 89.24%, and 68.04% on average with plot sizes of 1000m2 and 97.68%, 87.78% and 61.1% on average with plot sizes of 500m2.More than introducing a segmentation algorithm, this paper proposes a powerful framework featuring flexibility to support a series of segmentation methods including some of those recurring in the tree segmentation literature. The segmentation method may extend its applications to any data of topological nature or data that has a topological equivalent. © 2015 The Authors. Source

Dragoi M.,Stefan Cel Mare University of Suceava | Popa B.,Transylvania University | Blujdea V.,Forest Research and Management Institute
Forest Policy and Economics | Year: 2011

One of the most visible components of the Forestry Development Project, carried out between 2003 and 2009 by the World Bank and Romanian Government was 'PR support, Awareness Campaign and Development of PR products', meant to improve the communication between all stakeholders involved in sustainable forest management. The awareness campaign mainly consisted of nine meetings with the forest owners and nine workshops with all stakeholders, i.e. representatives of the forest inspectorates, county headquarters of the national forest administration, mass media, forest landowners, forest managers, logging companies and local authorities, including police and gendarmerie. The discussions, facilitated in each meeting by the three authors, were recorded and the minutes produced there have been further used for diagnosing the main interaction bottlenecks occurred between stakeholders. These discussions have been examined through the transactional analysis method in order to find out the main communication problems needed to addresses at national, regional and local level by the representatives of the public authorities in charge with implementing and supervising the forest policy. The main results of this analysis consist of a list of problems supposed to generate conflicts of various kinds (legal, technical, managerial and communicational) in Romanian forestry. The study has also revealed some important and frequent pitfalls that jeopardize the communication between prevailing stakeholders. Explaining them and their root causes could be a very useful input for further PR training programs and for the academic curricula. © 2010 Elsevier B.V. Source

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