scholarly journals Virtual pruning of 3D trees as a tool for managing shading effects in agroforestry systems

2021 ◽  
Author(s):  
Rafael Bohn Reckziegel ◽  
Jonathan P. Sheppard ◽  
Hans-Peter Kahle ◽  
Elena Larysch ◽  
Heinrich Spiecker ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Management Strategies ◽  
Ground Level ◽  
Agroforestry Systems ◽  
Spatiotemporal Resolution ◽  
Tree Structures ◽  
Woody Perennials ◽  
Crown Structure ◽  
Light Management ◽  
Shading Effects

AbstractLight is a limiting resource for crops within integrated land use systems especially those including woody perennials. The amount of available light at ground level can be modified by artificially pruning the overstory. Aiming to increase the understanding of light management strategies, we simulated the pruning of wild cherry trees and compared the shading effects of the resulting tree structures over a complete growing season, with fine spatiotemporal resolution. Original 3D-tree structures were retrieved employing terrestrial laser scanning and quantitative structure models, and subjected to two pruning treatments at low and high intensities. By using the ‘shadow model’, the analogous tree structures created diverse shaded scenarios varying in size and intensity of insolation reduction. Conventional pruning treatments reduced the crown structure to the uppermost portion of the tree bole, reducing the shading effects, and thus, shrinking the shaded area on the ground by up to 38%, together with the shading intensity. As an alternative, the selective removal of branches reduced the shading effects, while keeping a more similar spatial distribution compared to the unpruned tree. Hence, the virtual pruning of tree structures can support designing and selecting adequate tending operations for the management of light distribution in agroforestry systems. The evidence assembled in this study is highly relevant for agroecosystems and can be strategically used for maintaining, planning and designing integrated tree-crop agricultural systems.

scholarly journals Modelling and Comparing Shading Effects of 3D Tree Structures with Virtual Leaves

2021 ◽  
Vol 13 (3) ◽  
pp. 532 ◽  
Author(s):  
Rafael Bohn Reckziegel ◽  
Elena Larysch ◽  
Jonathan P. Sheppard ◽  
Hans-Peter Kahle ◽  
Christopher Morhart
Keyword(s):  
Prunus Avium ◽  
Agricultural Land ◽  
Laser Scanner ◽  
Agroforestry Systems ◽  
Hemispherical Photography ◽  
Wild Cherry ◽  
Tree Structures ◽  
3D Data ◽  
Shading Effects ◽  
Cherry Trees

Reduced solar radiation brought about by trees on agricultural land can both positively and negatively affect crop growth. For a better understanding of this issue, we aim for an improved simulation of the shade cast by trees in agroforestry systems and a precise estimation of insolation reduction. We present a leaf creation algorithm to generate realistic leaves to be placed upon quantitative structure models (QSMs) of real trees. Further, we couple it with an enhanced approach of a 3D model capable of quantifying shading effects of a tree, at a high temporal and spatial resolution. Hence, 3D data derived from wild cherry trees (Prunus avium L.) generated by terrestrial laser scanner technology formed a basis for the tree reconstruction, and served as leaf-off mode. Two leaf-on modes were simulated: realistic leaves, fed with leaf data from wild cherry trees; and ellipsoidal leaves, having ellipsoids as leaf-replacement. For comparison, we assessed the shading effects using hemispherical photography as an alternative method. Results showed that insolation reduction was higher using realistic leaves, and that the shaded area was greater in size than with the ellipsoidal leaves or leaf-off conditions. All shading effects were similarly distributed on the ground, with the exception of those derived through hemispherical photography, which were greater in size, but with less insolation reduction than realistic leaves. The main achievements of this study are: the enhancement of the leaf-on mode for QSMs with realistic leaves, the updates of the shadow model, and the comparison of shading effects. We provide evidence that the inclusion of realistic leaves with precise 3D data might be fundamental to accurately model the shading effects of trees.

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

Using LiDAR Point Clouds in Determination of the Scots Pine Stands Spatial Structure Meaning in the Conservation of Lichen Communities in “Bory Tucholskie” National Park

2019 ◽  
Vol 31 (1) ◽  
pp. 85-103
Author(s):  
Piotr Wężyk ◽  
Paweł Hawryło ◽  
Marta Szostak ◽  
Karolina Zięba-Kulawik ◽  
Monika Winczek ◽  
...  
Keyword(s):  
Spatial Structure ◽  
National Park ◽  
Laser Scanning ◽  
Ground Level ◽  
Point Clouds ◽  
Organic Layer ◽  
Active Protection ◽  
Scanning Lidar ◽  
Pine Stands ◽  
Biometric Features

Abstract The aim of the research carried out in 2018 and financed by the Forest Fund was the analysis of biometric features and parameters of pine stands in the area of the “Bory Tucholskie” National Park (PNBT), where a program of active protection of lichen was initiated in 2017. Environmental analyses were conducted in relation to selected biometric features of trees and stands using laser scanning (LiDAR), including ULS (Unmanned Laser Scanning; RIEGL VUX-1) and TLS (Terrestrial Laser Scanning; FARO FOCUS 3D; X130). Thanks to the application of LiDAR technology, the structure of pine stands was precisely determined by means of a series of descriptive statistics characterizing the 3D spatial structure of vegetation. Using the Trees Crown Model (CHM), the analysis of the volume of tree crowns and the volume of space under canopy was performed. For the analysed sub-compartments, GIS solar analyses were carried out for the solar energy reaching the canopy and the ground level due to active protection of lichen. Multispectral photos were obtained using a specialized RedEdge-M camera (MicaSense) mounted on the UAV multi rotor platform Typhoon H520 (Yuneec). Flights with a thermal camera were also performed in order to detect places on the ground with high temperature. Plant indices: NDVI, NDRE, GNDVI and GRVI were also calculated for sub-compartments. The data obtained in 2017 and 2018 were the basis for spatial and temporal analyses of 4-D changes in stands which were related to the removal of some trees and organic layer (litter, moss layer).

scholarly journals Spray deposition inside multiple-row nursery trees with a laser-guided sprayer1

2017 ◽  
Vol 35 (1) ◽  
pp. 13-23 ◽  
Author(s):  
H. Zhu ◽  
H. Liu ◽  
Y. Shen ◽  
Hengyu Liu ◽  
R. H. Zondag
Keyword(s):  
High Speed ◽  
Laser Scanning ◽  
Quercus Rubra ◽  
Spray Deposition ◽  
Field Tests ◽  
Red Oak ◽  
Northern Red Oak ◽  
Tree Structures ◽  
Speed Sensor ◽  
Tilia Tomentosa

Abstract Multiple-row container-grown trees require specially designed sprayers to achieve efficient spray delivery. A five-port air-assisted sprayer with both automatic and manual control modes was developed to discharge adequate spray deposition inside multiple-row trees. The sprayer resulted from integration of a high-speed laser-scanning sensor with a sophisticated nozzle flow control system, an embedded computer with a touch screen, a Doppler speed sensor, a specially-designed algorithm and an air-assisted sprayer base. It was able to detect target tree presence and measure target tree size, shape and leaf density. The sprayer then controlled the spray output of each nozzle to match tree structures. The sprayer was tested for its sprayer deposition quality inside canopies in a four-row sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench) field and another six-row northern red oak (Quercus rubra L.) field. Tests were conducted with the sprayer in variable-rate application (VRA) and constant-rate application (CRA) modes. The average spray deposit on foliage of trees was 1.37±0.47 μL cm−2 from VRA and 1.29±0.42 μL cm−2 from CRA in linden, and was 2.15±0.57 μL cm−2 from VRA and 2.72±0.94 μL cm−2 from CRA in red oak, respectively. In comparison, spray coverage on foliage of trees was 19.8±3.0% from VRA and 20.9±4.3% from CRA in the linden trial, and was 27.9±3.7% from VRA and 30.5±5.4% from CRA, respectively, in the red oak trial. The newly developed air-assisted sprayer in both VRA and CRA modes would be able to discharge adequate spray deposition inside multiple-row tree plants while conserving pesticide. Index words: environmental protection, pest control, pesticide, precision sprayer, spray coverage. Species used in this study: sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench), northern red oak (Quercus rubra L.).

scholarly journals Yield and performance of sugarcane in on-farm interface with rubber in Brazil

2006 ◽  
Vol 41 (2) ◽  
pp. 251-255
Author(s):  
Luís Fernando Guedes Pinto ◽  
Marcos Silveira Bernardes ◽  
Antônio Roberto Pereira
Keyword(s):  
Crop Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Management Strategies ◽  
Saccharum Officinarum ◽  
Agroforestry Systems ◽  
Plant Performance ◽  
Matter Production ◽  
And Performance ◽  
On Farm

Agroforestry systems are indicated as an alternative for sugarcane (Saccharum officinarum) cultivation in Piracicaba, SP, Brazil, however there are not many field experiments on plant performance under these conditions in the world. The objective of this work was to assess crop yield and partitioning in a sugarcane-rubber (Hevea brasiliensis) interface in on-farm conditions. The availability of irradiance for the crop along the interface was simulated and its effe ct over sugarcane dry matter production was tested. Crop yield was negatively affected by distance of the trees, but development and sucrose were not affected. Above ground dry matter increased from 16.6 to 51.5 t ha-1 from trees. Partitioning did not have a defined standard, as harvest index increased from 0.85 to 0.93, but specific leaf area was not significant along the transect, ranging from 13.48 to 15.73 m² kg-1. Light is the main factor of competition between the trees and the crop, but the relative importance of below ground interactions increases closer to the trees. Feasibility of the system depends on maturity of the trees and management strategies.

scholarly journals Seasonal Nearshore Occurrence of the Neurotoxin β N methylamino L alanine (BMAA) in Lake Winnipeg, Canada

2016 ◽  
Vol 5 (1) ◽  
pp. 110 ◽  
Author(s):  
Eva Pip ◽  
Kimber Munford ◽  
Lindsay Bowman
Keyword(s):  
Chlorophyll A ◽  
Nutrient Management ◽  
Management Strategies ◽  
Seasonal Fluctuation ◽  
Inverse Correlation ◽  
Water Quality Monitoring ◽  
Inorganic Phosphorus ◽  
Lake Winnipeg ◽  
Nitrate N ◽  
Shading Effects

Seasonal fluctuation patterns of the neurotoxic amino acid β N methylamino L alanine (BMAA) were examined at four-day intervals during the ice-free season in water at three nearshore stations in the south basin of Lake Winnipeg, Canada. BMAA patterns were significantly exponentially correlated with concurrent phaeophytin, and inversely with chlorophyll a, indicating that free BMAA concentrations increased as blooms declined. BMAA was also significantly related to preceding microcystin concentrations, and as chlorophyll a declined, the proportion of BMAA relative to microcystin increased. Cross correlations identified significant relationships between BMAA and immediately preceding nitrate-N/inorganic phosphorus ratios, nitrate-N, rainfall, and a marginal inverse correlation with inorganic phosphorus. Total suspended solids levels were also significantly associated with BMAA, likely due to shading effects. A very high BMAA concentration was found under collapse of intense bloom conditions. These results have implications for water quality monitoring, nutrient management strategies and public health.

A new drone laser scanning benchmark dataset for characterization of single-tree and forest biophysical properties

2021 ◽  
Author(s):  
Puliti Stefano ◽  
Grant D. Pears ◽  
Michael S. Watt ◽  
Edward Mitchard ◽  
Iain McNicol ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Laser Scanning ◽  
Method Development ◽  
Three Dimensional ◽  
Point Clouds ◽  
Benchmark Dataset ◽  
Validation Dataset ◽  
Tree Structures ◽  
Single Tree ◽  
Individual Trees

<p>Survey-grade drone laser scanners suitable for unmanned aerial vehicles (UAV-LS) allow the efficient collection of finely detailed three-dimensional information of tree structures. This data type allows forests to be resolved into discrete individual trees and has shown promising results in providing accurate in-situ observations of key forestry variables. New and improved approaches for analyzing UAV-LS point clouds have to be developed to transform the vast amounts of data from UAV-LS into actionable insights and decision support. Many different studies have explored various methods for automating single tree detection, segmentation, parsing into different tree components, and measurement of biophysical variables (e.g., diameter at breast height). Despite the considerable efforts dedicated to developing automated ways to process UAV-LS data into useful data, current methods tend to be tailored to small datasets, and it remains challenging to evaluate the performance of different algorithms based on a consistent validation dataset. To fill this knowledge gap and to further advance our ability to measure forests from UAV-LS data, we present a new benchmarking dataset. This data is composed of manually labelled UAV-LS data acquired a number of continents and biomes which span tropical to boreal forests. The UAV-LS data was collected exclusively used survey-grade sensors such as the Riegl VUX and mini-VUX series which are characterized by a point density in the range 1 – 10 k points m<sup>2</sup>. Currently, such data represent the state-of-the-art in aerial laser scanning data. The benchmark data consists of a library of single-tree point clouds, aggregated to sample plots, with each point classified as either stem, branch, or leaves. With the objective of releasing such a benchmark dataset as a public asset, in the future, researchers will be able to leverage such pre-existing labelled trees for developing new methods to measure forests from UAV-LS data. The availability of benchmarking datasets represents an important driver for enabling the development of robust and accurate methods. Such a benchmarking dataset will also be important for a consistent comparison of existing or future algorithms which will guide future method development.</p>

Remote Sensing based investigation of secondary mining deformation processes in a postglacial landscape of the Muzakow Arch Geopark (Western Poland) – preliminary results

2021 ◽  
Author(s):  
Jan Blachowski ◽  
Miłosz Becker ◽  
Anna Buczyńska ◽  
Natalia Bugajska ◽  
Dominik Janicki ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Laser Scanning ◽  
Raw Materials ◽  
Ground Level ◽  
Slope Instability ◽  
Opencast Mining ◽  
Ongoing Research ◽  
Preliminary Results ◽  
Underground Workings ◽  
Sink Hole

<p>The area of the present day Muzalkow Arch Geopark located on the border of Poland and Germany was subjected to a long term mining of lignite and other rock raw materials that ceased in the 70’ties of the 20<sup>th</sup> Century. The present-day geomorphological landscape of the research area is characterised by numerous and differentiated forms of anthropogenic origin (e.g. artificial lakes, subsidence troughs, sink holes, waste heaps) associated with underground and subsequently opencast mining of lignite in complex geological and tectonic conditions that result from glaciotectonic processes of subsequent stages of accumulation and weathering. It is thought that the area is presently subjected to geodynamic processes associated with weathering of exposed areas (lignite outcrops and waste heaps), destruction of shallow underground workings (subsidence troughs, sink holes) and changing hydrogeological conditions of the rock mass. The scale of these secondary deformations is presently unknown and these processes pose a threat the present day tourist development of the area, such as: sudden development of discontinuous terrain deformations, slope instability, flooding and subsequent dying of vegetation, etc.<br>Geodetic surveying and remote sensing (terrestrial, aerial and satellite) observations have been employed, apart from other in-situ investigations (geophysical and geological prospecting), to study the processes in one of the former coal mining fields in the geopark.<br>In this study preliminary results of selected geodetic field investigations, i.e. terrestrial laser scanning of a sink hole that showed on the surface in Autumn 2019 and UAV photogrammetric monitoring of an artificial waste rock tips have been reported. It has been found, based on mapping of old mining maps in GIS, that the sink hole is directly related to old shallow underground workings. Maximum depth of the analysed sink hole below ground level is  5.5 m and volume of subsidence is 35 m<sup>3</sup>. The location is being monitored to check if the geometry changes in time.<br>Whereas, comparison of digital elevation models of the investigated waste heap (one of three measured so far) showed development of gully erosion and downward movement of the weathered material. The deposition of material at the bottom of the heap averaged over a dozen cm and maximum of over 50 cm for a half year Summer period (from 15.05.2020 to 07.11.2020).<br>The presented results constitute a first approximation of 3D mapping and modelling the post-mining deformations in glaciotectonic landscape and constitute part of an ongoing research project financed from the Polish National Science Centre OPUS funds (no 2019/33/B/ST10/02975).</p>

scholarly journals Unmanned Aerial Systems for Monitoring Trace Tropospheric Gases

Atmosphere ◽  
2017 ◽  
Vol 8 (10) ◽  
pp. 206 ◽  
Author(s):  
Travis Schuyler ◽  
Marcelo Guzman
Keyword(s):  
Radiative Forcing ◽  
Trace Gases ◽  
Ground Level ◽  
Oxide Semiconductor ◽  
Atmospheric Composition ◽  
Cavity Surface ◽  
Unmanned Aerial Systems ◽  
Spatiotemporal Resolution ◽  
Atmospheric Trace Gases ◽  
Aerial Systems

The emission of greenhouse gases (GHGs) has changed the composition of the atmosphere during the Anthropocene. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating the contributions of different processes to radiative forcing. Currently there is no mobile platform that is able to quantify trace gases at altitudes <100 m above ground level that can achieve spatiotemporal resolution on the order of meters and seconds. Unmanned aerial systems (UASs) can be deployed on-site in minutes and can support the payloads necessary to quantify trace gases. Therefore, current efforts combine the use of UASs available on the civilian market with inexpensively designed analytical systems for monitoring atmospheric trace gases. In this context, this perspective introduces the most relevant classes of UASs available and evaluates their suitability to operate three kinds of detectors for atmospheric trace gases. The three subsets of UASs discussed are: (1) micro aerial vehicles (MAVs); (2) vertical take-off and landing (VTOL); and, (3) low-altitude short endurance (LASE) systems. The trace gas detectors evaluated are first the vertical cavity surface emitting laser (VCSEL), which is an infrared laser-absorption technique; second two types of metal-oxide semiconductor sensors; and, third a modified catalytic type sensor. UASs with wingspans under 3 m that can carry up to 5 kg a few hundred meters high for at least 30 min provide the best cost and convenience compromise for sensors deployment. Future efforts should be focused on the calibration and validation of lightweight analytical systems mounted on UASs for quantifying trace atmospheric gases. In conclusion, UASs offer new and exciting opportunities to study atmospheric composition and its effect on weather patterns and climate change.

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