scholarly journals INVISTIGATION ON CANOPY HEIGHT AND DENSITY DIFFERENTIATIONS IN THE MANAGED AND UNMANAGED FOREST STANDS USING LIDAR DATA (CASE STUDY: SHASTKALATEH FOREST, GORGAN)

2015 ◽  
Vol XL-1-W5 ◽  
pp. 775-779
Author(s):  
Sh. Shataee ◽  
J. Mohammadi
Keyword(s):  
Canopy Cover ◽  
Canopy Height ◽  
Systematic Sampling ◽  
Lidar Data ◽  
Forest Types ◽  
Forest Stands ◽  
Managed Forest ◽  
Northern Iran ◽  
Significant Difference ◽  
Unmanaged Forest

Forest management plans are interesting to keep the forest stand natural composite and structure after silvicultural and management treatments. In order to investigate on stand differences made by management treatments, comparing of these stands with unmanaged stands as natural forests is necessary. Aerial laser scanners are providing suitable 3D information to map the horizontal and vertical characteristics of forest structures. In this study, different of canopy height and canopy cover variances between managed and unmanaged forest stands as well as in two dominant forest types were investigated using Lidar data in Dr. Bahramnia forest, Northern Iran. The in-situ information was gathered from 308 circular plots by a random systematic sampling designs. The low lidar cloud point data were used to generate accurate DEM and DSM models and plot-based height statistics metrics and canopy cover characteristics. The significant analyses were done by independent T-test between two stands in same dominant forest types. Results showed that there are no significant differences between canopy cover mean in two stands as well as forest types. Result of statistically analysis on height characteristics showed that there are a decreasing the forest height and its variance in the managed forest compared to unmanaged stands. In addition, there is a significant difference between maximum, range, and mean heights of two stands in 99 percent confidence level. However, there is no significant difference between standard deviation and canopy height variance of managed and unmanged stands. These results showd that accomplished management treatments and cuttings could lead to reducing of height variances and converting multi-layers stands to two or single layers. Results are also showed that the canopy cover densities in the managed forest stands are changing from high dense cover to dense cover.

Importance of boreal forested wetlands for epiphytic macrolichen communities

2020 ◽  
Vol 50 (12) ◽  
pp. 1333-1339
Author(s):  
Tegan Padgett ◽  
Yolanda F. Wiersma
Keyword(s):  
Community Composition ◽  
Abies Balsamea ◽  
Canopy Cover ◽  
Tree Height ◽  
Forested Wetlands ◽  
Tree Age ◽  
Forested Wetland ◽  
Forest Types ◽  
Significant Difference ◽  
Face Threats

Forested wetlands provide ecosystem services and often support elevated levels of biodiversity and rare species. However, forested wetlands are understudied and face threats such as logging and land conversion. Epiphytic lichens are abundant in forested wetlands and may be useful to help delineate microhabitats across wetland–upland gradients. We investigated epiphytic macrolichen richness, diversity, and community composition in 15 sites in the Avalon Forest Ecoregion, Newfoundland, Canada. Within each site, we set up three parallel 40 m transects in (i) the forested wetland, (ii) the ecotone, and (iii) the upland forest. Along each transect, we selected five balsam fir (Abies balsamea (L.) Mill.) trees 10 m apart and surveyed for macrolichens on the lower bole. We collected data on tree height and tree diameter at breast height, which differed significantly among forest types. We also collected data on tree age and canopy cover, which did not differ significantly among forest types. Contrary to hypotheses suggesting that biodiversity is highest in ecotones, we found that mean macrolichen richness was significantly higher in wetlands, lower in the ecotones, and lowest in upland forests, and macrolichen diversity followed a similar pattern but with no significant difference among groups. Macrolichen community composition significantly differed among wetlands, ecotones, and upland forests. A lichen of conservation concern, Erioderma pedicellatum (Hue) P.M. Jørg., was detected primarily in forested wetlands, highlighting wetlands as key habitats for rare epiphytic macrolichens.

scholarly journals Spatio-temporal variation of throughfall in a hyrcanian plain forest stand in Northern Iran

2018 ◽  
Vol 66 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Saleh Yousefi ◽  
Seyed Hamidreza Sadeghi ◽  
Somayeh Mirzaee ◽  
Martine van der Ploeg ◽  
Saskia Keesstra ◽  
...  
Keyword(s):  
Canopy Cover ◽  
Forest Stand ◽  
Systematic Sampling ◽  
Northern Iran ◽  
The North ◽  
Lack Of Information ◽  
North Of Iran ◽  
Forest Watersheds ◽  
Spatio Temporal ◽  
Systematic Sampling Method

Abstract Elucidating segregation of precipitation in different components in forest stands is important for proper forest ecosystems management. However, there is a lack of information on important rainfall components viz. throughfall, interception and stemflow in forest watersheds particularly in developing countries. We therefore investigated the spatiotemporal variation of important component of throughfall for a forest stand in a Hyrcanian plain forest in Noor City, northern Iran. The study area contained five species of Quercus castaneifolia, Carpinus betulus, Populus caspica and Parrotia persica. The research was conducted from July 2013 to July 2014 using a systematic sampling method. Ninetysix throughfall collectors were installed in a 3.5 m × 3.5 m grid cells. The canopy covers during the growing/leaf-on (i.e., from May to November) and non-growing/leaf-off (i.e., from December to March) seasons were approximately 41% and 81%, respectively. The mean cumulative throughfall during the study period was 623±31 mm. The average throughfall (TF) as % of rainfall (TFPR) during leaf-on and leaf-off periods were calculated 56±14% and 77±10%, respectively. TF was significantly (R2 = 0.97, p = 0.00006) correlated with gross precipitation. Percent of canopy cover was not correlated with TF except when gross precipitation was <30 mm. A comparison between leaf-off and leaf-on conditions indicated a significantly higher TFPR and corresponding hotspots during leaf-on period. TFPR also differed between seasons with a maximum amount in winter (82%). The results of the study can be effectively used by forest watershed managers for better perception of hydrological behavior of the Hyrcanian forest in the north of Iran under different silvicultural circumstances leading to getting better ecosystem services.

scholarly journals A GIS-Based Algorithm to Generate a Lidar Pit-Free Canopy Height Model

2017 ◽  
Vol 11 (2) ◽  
pp. 89-95
Author(s):  
Casiana Marcu ◽  
Florian Stătescu ◽  
Nicoleta Iurist
Keyword(s):  
Canopy Height ◽  
Lidar Data ◽  
Forest Stands ◽  
Forest Development ◽  
Lidar Return ◽  
Canopy Height Model ◽  
Height Model

Abstract Lidar has provided significant benefits for forest development and engineering operations and provides a good means to collect information on forest stands. A common analysis using LiDAR data computes the CHM as a difference between DSM and DTM, create a DTM from the ground returns and a DSM from the first returns and subtract the two rasters, but how exactly are generated the DTM and the DSM. Irregular height variations, called data pits are present in the CHM and appear when the first Lidar return is far below the canopy. The purpose of this study is an approach that computes the CHM directly from height-normalized LiDAR points.

Abundance of Juvenile Eastern Box Turtles Relative to Canopy Cover in Managed Forest Stands in Alabama

2008 ◽  
Vol 7 (1) ◽  
pp. 128-130 ◽  
Author(s):  
Zachary Felix ◽  
Yong Wang ◽  
Helen Czech ◽  
Callie J. Schweitzer
Keyword(s):  
Canopy Cover ◽  
Forest Stands ◽  
Managed Forest ◽  
Box Turtles ◽  
Eastern Box Turtles

scholarly journals Cloth simulation-based construction of pit-free canopy height models from airborne LiDAR data

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Wuming Zhang ◽  
Shangshu Cai ◽  
Xinlian Liang ◽  
Jie Shao ◽  
Ronghai Hu ◽  
...  
Keyword(s):  
Tree Height ◽  
Point Clouds ◽  
Airborne Lidar ◽  
Canopy Height ◽  
Lidar Data ◽  
Cloth Simulation ◽  
Simulation Based ◽  
Maximum Tree Height ◽  
Airborne Lidar Data ◽  
Better Than

Abstract Background The universal occurrence of randomly distributed dark holes (i.e., data pits appearing within the tree crown) in LiDAR-derived canopy height models (CHMs) negatively affects the accuracy of extracted forest inventory parameters. Methods We develop an algorithm based on cloth simulation for constructing a pit-free CHM. Results The proposed algorithm effectively fills data pits of various sizes whilst preserving canopy details. Our pit-free CHMs derived from point clouds at different proportions of data pits are remarkably better than those constructed using other algorithms, as evidenced by the lowest average root mean square error (0.4981 m) between the reference CHMs and the constructed pit-free CHMs. Moreover, our pit-free CHMs show the best performance overall in terms of maximum tree height estimation (average bias = 0.9674 m). Conclusion The proposed algorithm can be adopted when working with different quality LiDAR data and shows high potential in forestry applications.

Improving the estimation of canopy cover from UAV-LiDAR data using a pit-free CHM-based method

2021 ◽  
pp. 1-16
Author(s):  
Shangshu Cai ◽  
Wuming Zhang ◽  
Shuangna Jin ◽  
Jie Shao ◽  
Linyuan Li ◽  
...  
Keyword(s):  
Canopy Cover ◽  
Lidar Data

Morphometric, genetic diversity and phylogenetic analysis of Taenia hydatigena (Pallas, 1766) larval stage in Iranian livestock

Parasitology ◽  
2019 ◽  
Vol 147 (2) ◽  
pp. 231-239
Author(s):  
Shahabeddin Sarvi ◽  
Laya Ebrahimi Behrestaghi ◽  
Abbas Alizadeh ◽  
Seyed Abdollah Hosseini ◽  
Shaban Gohardieh ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Larval Stage ◽  
Sequence Data ◽  
Genetic Difference ◽  
12S Rrna ◽  
Northern Iran ◽  
Taenia Hydatigena ◽  
Cysticercus Tenuicollis ◽  
Significant Difference ◽  
Cox 1

AbstractCysticercus tenuicollis as metacestode of Taenia hydatigena is the most prevalent taeniid species in livestock. Eighty-eight C. tenuicollis samples were collected from sheep (n = 44) and goats (n = 44) of the northern Iran from 2015 to 2016. The isolated parasites were characterized by morphometric keys. The DNA of the larval stage was extracted, amplified and sequenced targeting mitochondrial 12S rRNA and Cox 1 markers. A significant difference in larval rostellar hook length was observed in 12S rRNA haplotypes. Analysis of molecular variance of 12S rRNA indicated a moderate genetic diversity in the C. tenuicollis isolates. The pairwise sequence distance of C. tenuicollis showed an intra-species diversity of 0.3–0.5% and identity of 99.5–100%. Using the 12S rRNA sequence data we found a moderate genetic difference (Fst; 0.05421) in C. tenucollis isolates collected from livestock of the northern and southeastern regions of Iran. We concluded that the genetic variants of C. tenuicollis are being undoubtedly distributing mostly in different parts of Iran. Further studies with a larger number of T. hydatigena isolates collected from various intermediate and definitive hosts are needed to study this evolutionary assumption and also to determine the apparent genetic differences observed in the studied regions.

scholarly journals Comparison and Evaluation of Different Pit-Filling Methods for Generating High Resolution Canopy Height Model Using UAV Laser Scanning Data

2021 ◽  
Vol 13 (12) ◽  
pp. 2239
Author(s):  
Ying Quan ◽  
Mingze Li ◽  
Yuanshuo Hao ◽  
Bin Wang
Keyword(s):  
High Resolution ◽  
Laser Scanning ◽  
Evaluation Framework ◽  
Canopy Height ◽  
Filter Method ◽  
Individual Tree ◽  
Significant Difference ◽  
Point Interpolation ◽  
Canopy Height Model ◽  
Height Model

As a common form of light detection and ranging (LiDAR) in forestry applications, the canopy height model (CHM) provides the elevation distribution of aboveground vegetation. A CHM is traditionally generated by interpolating all the first LiDAR echoes. However, the first echo cannot accurately represent the canopy surface, and the resulting large amount of noise (data pits) also reduce the CHM quality. Although previous studies concentrate on many pit-filling methods, the applicability of these methods in high-resolution unmanned aerial vehicle laser scanning (UAVLS)-derived CHMs has not been revealed. This study selected eight widely used, recently developed, representative pit-filling methods, namely first-echo interpolation, smooth filtering (mean, medium and Gaussian), highest point interpolation, pit-free algorithm, spike-free algorithm and graph-based progressive morphological filtering (GPMF). A comprehensive evaluation framework was implemented, including a quantitative evaluation using simulation data and an additional application evaluation using UAVLS data. The results indicated that the spike-free algorithm and GPMF had excellent visual performances and were closest to the real canopy surface (root mean square error (RMSE) of simulated data were 0.1578 m and 0.1093 m, respectively; RMSE of UAVLS data were 0.3179 m and 0.4379 m, respectively). Compared with the first-echo method, the accuracies of the spike-free algorithm and GPMF improved by approximately 23% and 22%, respectively. The pit-free algorithm and highest point interpolation method also have advantages in high-resolution CHM generation. The global smooth filter method based on the first-echo CHM reduced the average canopy height by approximately 7.73%. Coniferous forests require more pit-filling than broad-leaved forests and mixed forests. Although the results of individual tree applications indicated that there was no significant difference between these methods except the median filter method, pit-filling is still of great significance for generating high-resolution CHMs. This study provides guidance for using high-resolution UAVLS in forestry applications.

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