STAND STRUCTURE AND SPATIAL DISTRIBUTION OF TREES AT DIFFERENT DEVELOPMENTAL STAGES AND STAND LAYERS IN MIXED STANDS IN ARTVIN REGION, TURKEY

Natural regeneration of beech in mixed stands of beech and fir was researched in the virgin forest Perucica, e.g. the basic elements of stand structure with special reference to beech regeneration characteristics, and the regeneration process in the conditions of broken stand canopy. The analysis included the stand development stages in he virgin forest based on the elements of structure, as well as the silvigenetic phases on a transect 10?100 m. The characteristics of beech regeneration (abundance, height, crown size, length of apical and lateral shoots) were measured on the selected regeneration areas (initial regeneration gaps). The silvigenetic phases on the transect and the interdependence of beech regeneration characteristics were assessed based on regeneration characteristics, ways of occurrence and spatial distribution of the young growth.

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Effect of long-term tending on qualitative and quantitative production in mixed stands of spruce, fir and beech on Motyky research plot

Journal of Forest Science ◽

10.17221/4686-jfs ◽

2012 ◽

Vol 49 (No. 3) ◽

pp. 108-124 ◽

Cited By ~ 3

Author(s):

I. Štefančík ◽

L. Štefančík

Keyword(s):

Stand Structure ◽

Mixed Stands ◽

Dynamic Changes ◽

Tree Species Composition ◽

Silvicultural Treatments ◽

Altitudinal Zone ◽

Control Dynamic ◽

Crown Thinning ◽

And Control

The paper is a contribution to research on thinnings in mixed (spruce-fir-beech) stands situated in the fifth forest altitudinal zone in the central part of Slovakia. Three plots were tended by free crown thinning while one plot was left without any planned silvicultural treatment (as a control). Dynamic changes in tree species composition, stand structure and quantitative production were evaluated for a period of 30 years. A special attention was paid to development of crop trees that are the main bearers of stand quality and quantity. The changes were compared with respect to differences between plots with long-term silvicultural treatments and control plot (without treatments).    

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Stand structure indices as tools to support forest management: an application in Trentino forests (Italy)

Journal of Forest Science ◽

10.17221/75/2012-jfs ◽

2013 ◽

Vol 59 (No. 4) ◽

pp. 159-168 ◽

Cited By ~ 20

Author(s):

F. Pastorella ◽

A. Paletto

Keyword(s):

Spatial Distribution ◽

Forest Management ◽

Species Diversity ◽

Species Composition ◽

Tree Species ◽

Stand Structure ◽

Composite Index ◽

Mutual Position ◽

Tree Species Composition ◽

North East

Stand structure and species diversity are two useful parameters to provide a synthetic measure of forest biodiversity. The stand structure is spatial distribution, mutual position, diameter and height differentiation of trees in a forest ecosystem and it highly influences habitat and species diversity. The forest stand and species diversity can be measured through indices that provide important information to better address silvicultural practices and forest management strategies in the short and long-term period. These indices can be combined in a composite index in order to evaluate the complex diversity at the stand level. The aim of the paper is to identify and to test a complex index (S-index) allowing to take into account both the tree species composition and the stand structure. S-index was applied in a case study in the north-east of Italy (Trentino province). The results show that the Norway spruce forests in Trentino province are characterized by a medium-low level of complexity (S-index is in a range between 0.14 and 0.46) due to a low tree species composition rather than to the stand structure (diametric differentiation and spatial distribution of trees).  

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Spatial distribution, advanced regeneration and stand structure of Nepalese Sal (Shorea robusta) forests subject to disturbances of different intensities

Forest Ecology and Management ◽

10.1016/j.foreco.2009.02.008 ◽

2009 ◽

Vol 257 (9) ◽

pp. 1966-1975 ◽

Cited By ~ 34

Author(s):

Indra Prasad Sapkota ◽

Mulualem Tigabu ◽

Per Christer Odén

Keyword(s):

Spatial Distribution ◽

Stand Structure ◽

Shorea Robusta ◽

Advanced Regeneration

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Analysis spatial distribution trees in forest stands

Glasnik Sumarskog fakulteta ◽

10.2298/gsf0693165s ◽

2006 ◽

pp. 165-176 ◽

Cited By ~ 2

Author(s):

Branko Stajic ◽

Milivoj Vuckovic

Keyword(s):

Spatial Distribution ◽

Growth Factors ◽

Stand Structure ◽

Horizontal Distribution ◽

Pure Stand ◽

Statistical Distributions ◽

Dispersion Index ◽

Study Results ◽

Growth Space ◽

Growth Development

The analyses of the horizontal distribution of trees have not been used in the research of stand structure in Serbia?s forestry to date. Taking into account the high economic and ecological applicability of such information, this paper deals with the numerical description of the form of spatial distribution of trees. The applied methods are the so-called methods of statistical distributions and dispersion index. The study results in the all-aged mixed stand of fir and beech and in the mature pure stand of fir on the mountain Goc show that all trees together, but also the trees per species, are predominantly randomly distributed in space, with the tendencies towards a weaker or stronger aggregation or uniformity. Based on the identified spatial distribution of trees, it can be concluded that in the greater part of the study stands the environment is homogeneous and the basic conditions of tree growth are uniform. This points to the fact that real assessment of growth development and the competition of fir and beech, due to the identified absence of a marked competition for the basic growth factors, emphasizes, primarily, the quantification of the competition for growth space. .

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Evolution of biodiversity in homogeneous Scots pine stands by an ecologically diversified management

Silva Gandavensis ◽

10.21825/sg.v60i0.862 ◽

1995 ◽

Vol 60 ◽

Author(s):

N. Lust ◽

B. Muys

Keyword(s):

Scots Pine ◽

Natural Regeneration ◽

Stand Structure ◽

Rotation Period ◽

Pine Forests ◽

Mixed Stands ◽

Noticeable Increase ◽

Hardwood Species ◽

Pine Stands ◽

Scots Pine Stands

This study evaluates three important parameters of biodiversity in first generation Scots pine forests on sandy soils: herbal layer, natural regeneration and stand structure. The research was undertaken in the Belgian Campine Region, where the original oak-birch forest had been destroyed in the course of time and finally been replaced by monocultures of Scots pine. These pine forests are characterised by a low biodiversity. In maturing stands of this type, however, a spontaneous increase of biodiversity is noticed. Herbal species diversity is very limited in all age classes. Spontaneous establishment of Scots pine seedlings is presently a widespread phenomenon in aging stands. Different regeneration patterns are found. Mainly due to the lengthening of the rotation in combination with the ingrowth of several hardwood species, the homogeneous Scots pine stands are gradually and spontaneously transformed into heterogeneous mixed stands, featuring a noticeable increase of biodiversity. Nevertheless, selected human interventions may further increase biodiversity. The fundamental management principles are discussed: avoidance of big disturbances, lengthening of the rotation period, use of native tree species, utilization of natural regeneration, protection of small valuable biotopes and permanent monitoring.

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Potential impact of climate change on the spatial distribution of key forest tree species in Italy under RCP4.5 for 2050s

10.21203/rs.3.rs-20281/v1 ◽

2020 ◽

Author(s):

Matteo Pecchi ◽

Maurizio Marchi ◽

Marco Moriondo ◽

Giovanni Forzieri ◽

Marco Ammoniaci ◽

...

Keyword(s):

Climate Change ◽

Spatial Distribution ◽

Species Richness ◽

Forest Management ◽

Tree Species ◽

Climate Models ◽

Forest Growth ◽

Mixed Stands ◽

Impact Of Climate Change ◽

Potential Impact

Abstract Background: Forests provide a range of ecosystem services essential for the human wellbeing and their ability is influenced by climate background and further connected to forest management strategies. Italy is a well-known biodiversity hotspot but an uncertainty assessment of the potential impact of climate change is still missing in this country. The aim of this paper is model the potential impact of climate change on 19 tree species occurring across the Italian forests using a species distribution modelling approach, six different Global Circulation Models (GCMs) and one Regional Climate Models (RCMs) for 2050s under an intermediate forcing scenario (RCP 4.5). Results: While no sensible variation in the spatial distribution of the total forested area has been predicted with some tree species gaining space and covering the spatial contractions of others, results showed substantial differences between each species and different climate models. The analyses reported an unchanged amount of total land suitability to forest growth in mountain areas while smaller values were predicted for valleys and floodplains than high-elevation areas. Pure woods were predicted as the most influenced when compared with mixed stands which are characterized by a greater species richness and therefore a supposed higher level of biodiversity and resilience to climate change threatens. Pure softwood stands (e.g. Pinus, Abies) were more sensitive than hardwoods (e.g. Fagus, Quercus), probably due to their artificial origin which established pure stands with tree species generally more prone to admixture with others in (semi)-natural ecosystems.Conclusions: Forest management could play a fundamental role to reduce the potential impact of climate change on forest ecosystems. Silvicultural practices should be aimed at increasing the species richness and favouring hardwoods currently growing as dominating species under conifers canopy, stimulating the natural regeneration, gene flow and supporting (spatial) migration processes.

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Using Social Media to Mine and Analyze Public Sentiment during a Disaster: A Case Study of the 2018 Shouguang City Flood in China

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi8040185 ◽

2019 ◽

Vol 8 (4) ◽

pp. 185 ◽

Cited By ~ 4

Author(s):

Xuehua Han ◽

Juanle Wang

Keyword(s):

Social Media ◽

Spatial Distribution ◽

Latent Dirichlet Allocation ◽

Developmental Stages ◽

Classification Model ◽

Economic Losses ◽

Public Servants ◽

Public Sentiment ◽

South Central ◽

The Government

Social media has been applied to all natural disaster risk-reduction phases, including pre-warning, response, and recovery. However, using it to accurately acquire and reveal public sentiment during a disaster still presents a significant challenge. To explore public sentiment in depth during a disaster, this study analyzed Sina-Weibo (Weibo) texts in terms of space, time, and content related to the 2018 Shouguang flood, which caused casualties and economic losses, arousing widespread public concern in China. The temporal changes within six-hour intervals and spatial distribution on sub-district and city levels of flood-related Weibo were analyzed. Based on the Latent Dirichlet Allocation (LDA) model and the Random Forest (RF) algorithm, a topic extraction and classification model was built to hierarchically identify six flood-relevant topics and nine types of public sentiment responses in Weibo texts. The majority of Weibo texts about the Shouguang flood were related to “public sentiment”, among which “questioning the government and media” was the most commonly expressed. The Weibo text numbers varied over time for different topics and sentiments that corresponded to the different developmental stages of the flood. On a sub-district level, the spatial distribution of flood-relevant Weibo was mainly concentrated in high population areas in the south-central and eastern parts of Shouguang, near the river and the downtown area. At the city level, the Weibo texts were mainly distributed in Beijing and cities in the Shandong Province, centering in Weifang City. The results indicated that the classification model developed in this study was accurate and viable for analyzing social media texts during a disaster. The findings can be used to help researchers, public servants, and officials to better understand public sentiments towards disaster events, to accelerate disaster responses, and to support post-disaster management.

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The accuracy of estimating individual tree variables with airborne laser scanning in a boreal nature reserve

Canadian Journal of Forest Research ◽

10.1139/x04-055 ◽

2004 ◽

Vol 34 (9) ◽

pp. 1791-1801 ◽

Cited By ~ 116

Author(s):

M Maltamo ◽

K Mustonen ◽

J Hyyppä ◽

J Pitkänen ◽

X Yu

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Laser Scanning ◽

Stand Structure ◽

Tree Height ◽

Heterogeneous Structure ◽

Mixed Stands ◽

Individual Tree ◽

Tree Layer ◽

Pine Trees

This study examines the ability of high-density laser scanning to produce single-tree estimates in mixed stands of heterogeneous structure. Individual trees were detected from a constructed digital canopy height model by locating local maxima of the height values. The reference material comprised accurately measured field data for 10 mapped sample plots containing Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and different birches. To verify the accuracy of height measurements of single trees in more detail, the height of 29 Scots pine trees and their annual shoots of the last few years was carefully measured with a tacheometer and a glass fibre rod. The considered variables were the proportion of detected trees and tree height. As more than 80% of the dominant trees were detected, the results indicated that laser scanning can accurately describe the trees of the dominant tree layer. Because of the dense understorey tree layer in most of the sample plots, about 40% of all trees were detected. On the plot level, the stand structure affected the accuracy of the results considerably. The scanning-based tree height was most accurate for Norway spruce and least accurate for birches. The height of the separately measured 29 Scots pine trees was obtained with an accuracy of ±50 cm or better.

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