Deviation from power law, spatial data of forest canopy gaps, and three lattice models

Abstract:Natural tree canopy gaps allow sunlight to penetrate to the forest floor, a major environmental component and resource for many tropical rain-forest species. We compare here how butterflies use sunny areas created by the natural gaps in canopies in comparison with adjacent closed-canopy areas. We chose butterflies as our focal organisms as they are taxonomically tractable and mobile, yet habitat sensitive. Previous studies have shown that butterfly diversity in tropical forests responds to varying degrees of canopy openness. Here we assess butterfly behavioural responses to gaps and equivalent sized closed-canopy patches. Butterfly occupancy time and behaviour were simultaneously observed 61 times in gaps and 61 times in equivalent sized closed-canopy patches across four sites in a tropical rain forest in northern Borneo. Out of the 20 most frequently recorded species, 12 were more frequently recorded or spent more time in gaps, four occurred more frequently in closed-canopy areas, and four showed no significant differences. Overall agonistic, basking, patrolling and resting were more common in gaps compared with the closed canopy. Many butterfly species have complex behavioural requirements for both gaps and closed canopies, with some species using these different areas for different behaviours. Each butterfly species had particular habitat requirements, and needed both canopy gaps and closed canopy areas for ecological and behavioural reasons, emphasizing the need for natural light heterogeneity within these systems.

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The impact of lianas on tree regeneration in tropical forest canopy gaps: evidence for an alternative pathway of gap-phase regeneration

Journal of Ecology ◽

10.1046/j.1365-2745.2000.00489.x ◽

2000 ◽

Vol 88 (4) ◽

pp. 655-666 ◽

Cited By ~ 269

Author(s):

Stefan A. Schnitzer ◽

James W. Dalling ◽

Walter P. Carson

Keyword(s):

Tropical Forest ◽

Forest Canopy ◽

Alternative Pathway ◽

Canopy Gaps ◽

Tree Regeneration ◽

Gap Phase ◽

The Impact ◽

Tropical Forest Canopy

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Airborne laser scan data: a valuable tool to infer partial beam-blockage in urban environment

10.5194/amt-2016-76 ◽

2016 ◽

Author(s):

Roberto Cremonini ◽

Dmitri Moisseev ◽

V. Chandrasekar

Keyword(s):

Spatial Data ◽

Urban Areas ◽

Forest Canopy ◽

Propagation Model ◽

Data Sets ◽

Weather Radars ◽

Airborne Laser ◽

Digital Elevation ◽

Spatial Data Sets ◽

Scan Data

Abstract. High spatial resolution weather radar observations are of primary relevance for hydrological applications in urban areas. However, when weather radars are located within metropolitan areas, partial beam blockages and clutter by buildings can seriously affect the observations. Standard simulations with simple beam propagation models and digital elevation models (DEMs) are usually not able to evaluate the buildings contribution to partial beam blockages. In the recent years airborne laser scanners (ALS) evolved to the state-of-the-art technique for topographic data acquisition. ALS data, providing small footprint diameters (10–30 cm), allow accurate reconstruction of buildings and forest canopy heights. Analysing the three weather C-band radars located in the metropolitan area of Helsinki, Finland, the present study investigates the benefits of using ALS data for quantitative estimations of partial beam blockings. The results obtained applying beam standard propagation model are compared with stratiform 24-hour rainfall accumulation to evaluate the effect of partial beam blocking due to the constructions and trees. To provide the physical interpretation of the results, the detailed analysis of beam occultations is achieved by open spatial data sets and interface services with open source Geographic Information Systems.

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Generating a three-dimensional measuring scene for the forest sector as based on modern geodetic technologies

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/875/1/012083 ◽

2021 ◽

Vol 875 (1) ◽

pp. 012083

Author(s):

N Begliarov ◽

E Mitrofanov ◽

V Kiseleva

Keyword(s):

Spatial Data ◽

Laser Scanning ◽

Forest Canopy ◽

Method Development ◽

Three Dimensional ◽

Terrestrial Laser Scanning ◽

Accurate Information ◽

Forest Sector ◽

Individual Tree ◽

Cloud Of Points

Abstract Modern geodetic technologies of gathering three-dimensional spatial data incorporate terrestrial laser scanning and aerial photo survey from unmanned aerial vehicles. The combination of these technologies and joint result of survey provide the data of 3D point model and accurate information on trunks and crowns of individual trees. The paper examines the experiment with the application of method of formation of 3D measuring scene in the form of dense cloud of points combining the results of terrestrial laser scanning and materials of photogrammetric processing of UAV-provided data. The method eliminates basic shortcomings of each technology, enhances their advantages, and opens the way to the compilation of more representative 3D measuring scenes. A specific advantage of the method is the outcropping of detailed information on the form, size and condition of individual tree crowns. This option finds a practical application in landscape evaluation and design, remote measuring of trunk parameters excluding the felling of model trees for the compilation of regional timber account tables. The closest perspectives of method development are related to increasing the accuracy of combined survey by specifying flight missions and working with the light regime under forest canopy.

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