scholarly journals Influence of Natural and Anthropogenic Linear Canopy Openings on Forest Structural Patterns Investigated Using LiDAR

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 540 ◽  
Author(s):  
Udayalakshmi Vepakomma ◽  
Daniel Kneeshaw ◽  
Louis De Grandpré
Keyword(s):  
Forest Structure ◽  
Black Spruce ◽  
Forest Biomass ◽  
High Density ◽  
Airborne Lidar ◽  
Power Lines ◽  
Gap Fraction ◽  
Spruce Stands ◽  
Edge Influence ◽  
Forest Conditions

In much of the commercial boreal forest, dense road networks and energy corridors have been developed to access natural resources with unintended and poorly understood effects on surrounding forest structure. In this study, we compare the effects of anthropogenic and natural linear openings on surrounding forest conditions in black spruce stands (gap fraction, tree and sapling height, and density). Forest structure within a 100 m band around the edges of anthropogenic (roads and power lines), natural linear openings (streams), and a reference black spruce forest was measured by identifying individual stems and canopy gaps on recent high density airborne LiDAR canopy height models. CUSUM curves were used to assess the distance of edge influence. Forests surrounding anthropogenic openings were found to be gappier, less dense, and have smaller trees than those around natural openings. Forests were denser around natural and anthropogenic linear openings than in the reference forest with edge effects observed up to 24–75 m and 18–54 m, respectively, into the forest. A high density of saplings in the gappier forests surrounding anthropogenic openings may eventually lead to a higher forest biomass in the zone area surrounding roads as is currently observed around natural openings.

Forest structure and composition at young fire and cut edges in black spruce boreal forest

2004 ◽  
Vol 34 (2) ◽  
pp. 289-302 ◽  
Author(s):  
Karen A Harper ◽  
Daniel Lesieur ◽  
Yves Bergeron ◽  
Pierre Drapeau
Keyword(s):  
Species Composition ◽  
Boreal Forest ◽  
Forest Structure ◽  
Black Spruce ◽  
Cumulative Effect ◽  
Mean Values ◽  
Clear Cutting ◽  
Interior Forest ◽  
Edge Influence ◽  
Range Of Variation

We compared structure and composition at forest edges created by wildfire and clear-cutting in black spruce (Picea mariana (Mill.) BSP) dominated boreal forest in northwestern Quebec. Forest structure and plant species composition were sampled along transects perpendicular to eight 3- to 4-year-old fire edges and eight 2- to 5-year-old cut edges. Significance of edge influence was assessed by comparing mean values at different distances from the edge to the range of variation in interior forest. The influence of clearcut edges was minimal, generally extending only 5 m from the edge, and included greater log density and different species composition, compared with interior forest. At fire edges, prominent responses to edge creation included increased snag density and lower moss cover, compared with interior forest, extending up to 40 m into the forest. This initial structural change was likely due to partial burning extending into the forest. Overall, fire edges had more snags and a different species composition than cut edges. Our hypothesis that edge influence is more extensive at fire edges than at cut edges was supported for overstory and understory structure, but not for species composition. We suggest that there is a need for management to consider the cumulative effect of the loss of fire edges on the landscape.

scholarly journals Supervised Classification of Power Lines from Airborne LiDAR Data in Urban Areas

2017 ◽  
Vol 9 (8) ◽  
pp. 771 ◽  
Author(s):  
Yanjun Wang ◽  
Qi Chen ◽  
Lin Liu ◽  
Dunyong Zheng ◽  
Chaokui Li ◽  
...  
Keyword(s):  
Urban Areas ◽  
Supervised Classification ◽  
Airborne Lidar ◽  
Power Lines ◽  
Lidar Data ◽  
Airborne Lidar Data

scholarly journals Forest biomass and wood consumption In the lower course of the Amazon: a case study of rhe Urubueua Island

1999 ◽  
Vol 29 (1) ◽  
pp. 79-79 ◽  
Author(s):  
Akio TSUCHIYA ◽  
Mario HIRAOKA
Keyword(s):  
Water Stress ◽  
Forest Structure ◽  
Forest Biomass ◽  
Human Intervention ◽  
Terra Firme ◽  
Wood Volume ◽  
The Difference ◽  
Várzea Forests ◽  
Wood Consumption

Várzea and terra-firme forests in the lower course of the Amazon were compared in terms of forest structure, wood volume increments and forest biomass. The wood volume of várzea forests was smaller than that of terra-firme forests, particularly when severe human intervention such as the cultivation of açaí palm occurred. The difference was even greater in the forest weight comparison because of the lower wood density of várzea trees. These trees are not directly influenced by water stress during the dry season, while late wood with a high density is formed in the terra-firme trees. The annual forest disappearance area due to firewood for tile factories was estimated to be about 276 ha on the island investigated, which had an area of 36,200 ha. Assuming that the forests are rotatively cultivated every 25 to 30 years, the total deforestation area is 6,870-6,948 ha in 25 years and 8,244~8,337 ha in 30 years. This result means that the balance between forest biomass and utilization is not in crisis, however, this balance might be lost as long as substitutive energy such as electricity is not supplied.

scholarly journals Comparative Height Growth of Eastern Larch and Black Spruce in Northwestern Ontario

1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Height Growth ◽  
Larix Laricina ◽  
Stem Analysis ◽  
Northwestern Ontario ◽  
Analysis Methods ◽  
Spruce Stands

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.

Using airborne LiDAR to assess spatial heterogeneity in forest structure on Mount Kilimanjaro

2017 ◽  
Vol 32 (9) ◽  
pp. 1881-1894 ◽  
Author(s):  
Stephan Getzin ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Spatial Heterogeneity ◽  
Forest Structure ◽  
Airborne Lidar ◽  
Mount Kilimanjaro

scholarly journals Amazon forest structure generates diurnal and seasonal variability in light utilization

2015 ◽  
Vol 12 (23) ◽  
pp. 19043-19072 ◽  
Author(s):  
D. C. Morton ◽  
J. Rubio ◽  
B. D. Cook ◽  
J.-P. Gastellu-Etchegorry ◽  
M. Longo ◽  
...  
Keyword(s):  
Forest Structure ◽  
Seasonal Variability ◽  
Seasonal Changes ◽  
Forest Productivity ◽  
Dry Season ◽  
Airborne Lidar ◽  
Amazon Forest ◽  
Light Saturation ◽  
Light Utilization ◽  
Saturation Effects

Abstract. The complex three-dimensional (3-D) structure of tropical forests generates a diversity of light environments for canopy and understory trees. Understanding diurnal and seasonal changes in light availability is critical for interpreting measurements of net ecosystem exchange and improving ecosystem models. Here, we used the Discrete Anisotropic Radiative Transfer (DART) model to simulate leaf absorption of photosynthetically active radiation (lAPAR) for an Amazon forest. The 3-D model scene was developed from airborne lidar data, and local measurements of leaf reflectance, aerosols, and PAR were used to model lAPAR under direct and diffuse illumination conditions. Simulated lAPAR under clear sky and cloudy conditions was corrected for light saturation effects to estimate light utilization, the fraction of lAPAR available for photosynthesis. Although the fraction of incoming PAR absorbed by leaves was consistent throughout the year (0.80–0.82), light utilization varied seasonally (0.67–0.74), with minimum values during the Amazon dry season. Shadowing and light saturation effects moderated potential gains in forest productivity from increasing PAR during dry season months when the diffuse fraction from clouds and aerosols was low. Comparisons between DART and other models highlighted the role of 3-D forest structure to account for seasonal changes in light utilization. Our findings highlight how directional illumination and forest 3-D structure combine to influence diurnal and seasonal variability in light utilization, independent of further changes in leaf area, leaf age, or environmental controls on canopy photosynthesis. Changing illumination geometry constitutes an alternative biophysical explanation for observed seasonality in Amazon forest productivity without changes in canopy phenology.

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
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