scholarly journals Fitting Tree Height Distributions in Natural Beech Forest Stands of Guilan (Case Study: Masal)

2019 ◽  
Vol 7 (14) ◽  
pp. 1-9
Author(s):  
Iraj Hassanzad Navroodi ◽  
◽  
Ismaeil moradi ◽  
Keyword(s):  
Tree Height ◽  
Beech Forest ◽  
Forest Stands

scholarly journals A protocol for sampling vascular epiphyte richness and abundance

2009 ◽  
Vol 25 (2) ◽  
pp. 107-121 ◽  
Author(s):  
Jan H. D. Wolf ◽  
S. Robbert Gradstein ◽  
Nalini M. Nadkarni
Keyword(s):  
Tree Height ◽  
Dry Weight ◽  
Mantel Test ◽  
Tree Size ◽  
Tree Level ◽  
Trunk Diameter ◽  
Host Trees ◽  
Epiphyte Communities ◽  
Vascular Epiphyte

Abstract:The sampling of epiphytes is fraught with methodological difficulties. We present a protocol to sample and analyse vascular epiphyte richness and abundance in forests of different structure (SVERA). Epiphyte abundance is estimated as biomass by recording the number of plant components in a range of size cohorts. Epiphyte species biomass is estimated on 35 sample-trees, evenly distributed over six trunk diameter-size cohorts (10 trees with dbh > 30 cm). Tree height, dbh and number of forks (diameter > 5 cm) yield a dimensionless estimate of the size of the tree. Epiphyte dry weight and species richness between forests is compared with ANCOVA that controls for tree size. SChao1 is used as an estimate of the total number of species at the sites. The relative dependence of the distribution of the epiphyte communities on environmental and spatial variables may be assessed using multivariate analysis and Mantel test. In a case study, we compared epiphyte vegetation of six Mexican oak forests and one Colombian oak forest at similar elevation. We found a strongly significant positive correlation between tree size and epiphyte richness or biomass at all sites. In forests with a higher diversity of host trees, more trees must be sampled. Epiphyte biomass at the Colombian site was lower than in any of the Mexican sites; without correction for tree size no significant differences in terms of epiphyte biomass could be detected. The occurrence of spatial dependence, at both the landscape level and at the tree level, shows that the inclusion of spatial descriptors in SVERA is justified.

scholarly journals SANITARY CONDITION OF PICEA ABIES (L. ) KARST. YOUNG FOREST STANDS DEPENDING ON THE SPATIAL SPECIFICITY

AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Jelena RUBA ◽  
Olga MIEZITE ◽  
Imants LIEPA
Keyword(s):  
Risk Factors ◽  
Picea Abies ◽  
Tree Height ◽  
Impact Factors ◽  
Forest Stands ◽  
Sanitary Condition ◽  
Young Forest ◽  
Young Forests ◽  
Spatial Specificity ◽  
Sanitary State

As a result of nature resources intensive use, most of ecosystems have beenconverted. Anthropogenic impact includes changes of forest stands structure andtheir spatial specificity in the forest area. Accordingly the sanitary state of Norwayspruce young forest stands can be affected by different risk impact factors ofmanagement. The aim of the research was to analyze the spruce Picea abies (L. )Karst. young forest stands sanitary condition depending on forest plots spatialspecificity and location in the forest areas. The data were collected in 4 regions ofLatvia in spruce young forest stands (1 - 40 years old). The research was conductedin young natural and artificial stands (pure – 44, mixed – 42). In total 502 sampleplots with a total area of 28250 mwere installed. The particular plot size (25, 50,100 and 200 m) were selected depending on the stand average tree height, whiletheir number depended on the forest stand area. A total area of investigated foreststands were 127. 5 hectares. Results showed that the expression of spatial specificsdepended on risk factors and their intensity, as well as the environmentalcharacteristics. Damages caused by abiotic risk factors at different forest standswere not the same regarding intensity, nature and volume, but more or less closelywere related to all site conditions. Spatial specificity of forest stands area (regularand irregular), as well as their location in the forest massif significantly affects thespruce young forests sanitary status (respectively p=0. 027 and p=0. 002). Differentrisk factors damage to forests, bordering with spruce or pine young growths,cutovers and various types of infrastructure, were identified as much moreimportant.

scholarly journals Estimation of Tree Height and Forest Biomass Using Airborne LiDAR Data: A Case Study of Londiani Forest Block in the Mau Complex, Kenya

2017 ◽  
Vol 07 (02) ◽  
pp. 255-269 ◽  
Author(s):  
Faith Kagwiria Mutwiri ◽  
Patroba Achola Odera ◽  
Mwangi James Kinyanjui
Keyword(s):  
Forest Biomass ◽  
Tree Height ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Airborne Lidar Data

scholarly journals Harvester Productivity in Inclined Terrain with Extended Machine Operating Trail Intervals: A German Case Study Comparison of Standing and Bunched Trees

2020 ◽  
Vol 12 (21) ◽  
pp. 9168
Author(s):  
Ferréol Berendt ◽  
Eduardo Tolosana ◽  
Stephan Hoffmann ◽  
Paula Alonso ◽  
Janine Schweier
Keyword(s):  
Tree Species ◽  
Timber Harvesting ◽  
Forest Stands ◽  
Operational Conditions ◽  
Thinning Operation ◽  
Standing Trees ◽  
Broadleaved Tree Species ◽  
Broadleaved Tree ◽  
Multiple Tree

The complexity of highly structured forests with multiple tree species, especially when coniferous and broadleaved tree species are mixed, as well as stands with extended machine operating trail spacing and inclined terrain, create challenging operational conditions for mechanized timber harvesting and extraction. Motor-manually felling trees within the midfield and bunching them at the machine operating trails, prior to the arrival of a harvester-forwarder system, is a complex operation. The aim of this study was to assess and compare tethered harvester productivities of a thinning operation, for felling and processing standing trees and for processing bunched trees, through a time study in forest stands with 40-m distances between machine operating trails. Total operational costs of the analyzed thinning operation were 69 €/m3o.b., including extraction using a multiple forwarder approach. Tree species, merchantable timber volume, and whether the trees were standing or presented as bunched logs all had a significant effect on the harvester time consumption. Moreover, harvester positioning time was significantly shorter when trees were already bunched at the machine operating trail. While the productivity of standing or bunched spruce trees did not differ significantly between the cases (approximately 18 m3o.b./productive machine hours excluding all delays (PMH0)), the productivity of standing broadleaved tree species (8.3 m3o.b./PMH0) was much lower than that of bunched trees (15.5 m3o.b./PMH0). Thus, the described timber harvesting and extraction system may be a valuable option for forest stands with high proportion of broadleaved trees.

scholarly journals Impacts of Restoration Projects on a Sahelian Woody Vegetation after 21 Years: The Simiri Plateaus (Niger) Case Study

2019 ◽  
pp. 1-12
Author(s):  
Laouali Abdou ◽  
Boubacar Moussa Mamoudou ◽  
Habou Rabiou ◽  
Ali Mahamane ◽  
Josiane Seghieri
Keyword(s):  
Vegetation Cover ◽  
Recovery Rate ◽  
Crop Yields ◽  
Basal Area ◽  
Tree Height ◽  
Woody Species ◽  
Woody Vegetation ◽  
Number Of Stems ◽  
Similar Site

To face the soil and vegetation degradation in Niger, anti-erosion structures, such as scarification of the surface of the ground, half-moons, benches, trenches, stony cordons, were built in 1989 on three Simiri plateaus. Native and introduced woody species were planted and grasses were sown within the structures. This study aims at evaluating what has become the restoration of the woody vegetation cover compared to an un-restored woody cover located on a nearby similar site. Dendrometric parameters and alpha and beta diversities of the four woody stands in 36 sampled plots were analyzed and compared. The following dendrometric values were found significantly lower in the control than in the restored stands: 3.9% against 12.4-16.8% for the recovery rate, 4.3 against 6.3-10.2 cm for the largest stem diameter, 0.2 against 0.8-1.2 m²/ha for the basal area, and 1.6 against 2.0-2.5 m for the tree height. However, the number of stems per trees was found significantly greater in the un-restored stand (6.6) than in the restored ones (1.8-2.7). The values of dendrometric parameters remained low, as well as the alpha and beta diversities whatever the stand. Nevertheless, population perceptions on the restoration impacts that were collected through focus groups indicated positive impacts on downstream crop yields.

scholarly journals Hipsometric relationship modeling using data sampled in tree scaling and inventory plots

2011 ◽  
Vol 35 (1) ◽  
pp. 157-164 ◽  
Author(s):  
Valdir Carlos Lima de Andrade ◽  
Helio Garcia Leite
Keyword(s):  
Standard Error ◽  
Tree Height ◽  
Forest Stands ◽  
F Test ◽  
Graphic Analysis ◽  
Using Data

This work evaluated eight hypsometric models to represent tree height-diameter relationship, using data obtained from the scaling of 118 trees and 25 inventory plots. Residue graphic analysis and percent deviation mean criteria, qui-square test precision, residual standard error between real and estimated heights and the graybill f test were adopted. The identity of the hypsometric models was also verified by applying the F(Ho) test on the plot data grouped to the scaling data. It was concluded that better accuracy can be obtained by using the model prodan, with h and d1,3 data measured in 10 trees by plots grouped into these scaling data measurements of even-aged forest stands.

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