Crown Volume Research Articles

How dynamic growth of avenue trees affects particulate matter dispersion: CFD simulations in street canyons

This study combined parameterized tree growth model, Reynolds Averaged Navier–Stokes model and revised generalized drift flux model to investigate the effect of dynamic growth of avenue trees on atmospheric particulate pollution dispersion in street canyons. We tested conditions with three street canyon aspect ratios (H/W = 0.45, 0.9 and 1.8) and five common avenue tree species (Gingko biloba, Aesculus chinensis, Acer buergerianum, Liriodendron chinense and Cedrus deodar). Results demonstrated that: 1) Avenue tree age was strongly correlated with their height and crown diameter (R2 ≥ 0.71). 2) PM reduction ratio increased significantly as tree age increased. G. biloba was the most effective at removing the pedestrian-level PM10, while L. chinenses has the greatest capacity to reduce pedestrian-level PM2.5. 3) Pedestrian-level PM on the windward street-side was positively related to H/W ratios. Maximum PM was measured on the leeward street-side at H/W = 0.9. 4) Tree height, crown diameter and crown volume in the street canyons were the primary factors affecting the pedestrian-level PM reduction ratio, while leaf area index and crown base height had less influence. Our results could provide guidelines for selecting avenue trees within street canyons and appropriate biometric characteristics during different plant stages to enhance urban sustainability.

Towards Tree Green Crown Volume: A Methodological Approach Using Terrestrial Laser Scanning

Crown volume is a tree attribute relevant in a number of contexts, including photosynthesis and matter production, storm resistance, shadowing of lower layers, habitat for various taxa. While commonly the total crown volume is being determined, for example by wrapping a convex hull around the crown, we present here a methodological approach towards assessing the tree green crown volume (TGCVol), the crown volume with a high density of foliage, which we derive by terrestrial laser scanning in a case study of solitary urban trees. Using the RGB information, we removed the hits on stem and branches within the tree crown and used the remaining leaf hits to determine TGCVol from k-means clustering and convex hulls for the resulting green 3D clusters. We derived a tree green crown volume index (TGCVI) relating the green crown volume to the total crown volume. This TGCVI is a measure of how much a crown is “filled with green” and scale-dependent (a function of specifications of the k-means clustering). Our study is a step towards a standardized assessment of tree green crown volume. We do also address a number of remaining methodological challenges.

Assessing pollination disservices of urban street-trees: The case of London-plane tree (Platanus x hispanica Mill. ex Münchh)

Platanusx hispanica (London plane) is a tree species widely used in urban areas due to the diversity of ecosystem services it provides. However, its functions also have some negative effects or associated disservices, such as the emission of Biogenic Volatile Organic Compounds (BVOCs) and allergens. This work aims to analyze the effect that urban environmental conditions and air pollutants have on pollen emissions of plane tree. The study has been carried out in Granada, in the southeast of the Iberian Peninsula, a city with a Mediterranean climate and one of the most polluted in Spain. Granada is also one of the Mediterranean cities in which the increase in the percentage of the population affected by allergy to Platanus pollen in recent decades has been most significant. The 1992–2019 Platanus pollen data series has been considered to establish the main aerobiological parameters, trends and correlations with meteorological variables and particulate and gaseous atmospheric pollutants, both before and during the flowering period. The average Seasonal Pollen Integral (SPIn) of about 2700 pollen grains has shown a significant increase throughout the series. This increase in allergen emissions could be related to the increase in crown volume associated with tree growth, but also to other environmental factors. Precipitation and minimum temperatures of the winter prior to flowering were the parameters that have shown the most influence with SPIn, while O3 and NOx are the pollutants that have the most effect on the peak value. Due to the good adaptation that London plane has to changing climatic conditions in urban environments, its hegemonic presence as an element of Urban Green infrastructure must be reviewed so that the net balance of ecosystem services is not diminished by the disservices.

Suitability of Airborne and Terrestrial Laser Scanning for Mapping Tree Crop Structural Metrics for Improved Orchard Management

Airborne Laser Scanning (ALS) and Terrestrial Laser Scanning (TLS) systems are useful tools for deriving horticultural tree structure estimates. However, there are limited studies to guide growers and agronomists on different applications of the two technologies for horticultural tree crops, despite the importance of measuring tree structure for pruning practices, yield forecasting, tree condition assessment, irrigation and fertilization optimization. Here, we evaluated ALS data against near coincident TLS data in avocado, macadamia and mango orchards to demonstrate and assess their accuracies and potential application for mapping crown area, fractional cover, maximum crown height, and crown volume. ALS and TLS measurements were similar for crown area, fractional cover and maximum crown height (coefficient of determination (R2) ≥ 0.94, relative root mean square error (rRMSE) ≤ 4.47%). Due to the limited ability of ALS data to measure lower branches and within crown structure, crown volume estimates from ALS and TLS data were less correlated (R2 = 0.81, rRMSE = 42.66%) with the ALS data found to consistently underestimate crown volume. To illustrate the effects of different spatial resolution, capacity and coverage of ALS and TLS data, we also calculated leaf area, leaf area density and vertical leaf area profile from the TLS data, while canopy height, tree row dimensions and tree counts) at the orchard level were calculated from ALS data. Our results showed that ALS data have the ability to accurately measure horticultural crown structural parameters, which mainly rely on top of crown information, and measurements of hedgerow width, length and tree counts at the orchard scale is also achievable. While the use of TLS data to map crown structure can only cover a limited number of trees, the assessment of all crown strata is achievable, allowing measurements of crown volume, leaf area density and vertical leaf area profile to be derived for individual trees. This study provides information for growers and horticultural industries on the capacities and achievable mapping accuracies of standard ALS data for calculating crown structural attributes of horticultural tree crops.

Confirmation of a wear-compensation mechanism in dental roots of ruminants.

Diet affects many factors of an animal's anatomy, but teeth are a specific focus of dietary research, as their durability lends them to record information on a large variety of scales. Abrasive diets like those of grazing herbivores are known to wear down teeth, but how that wear affects tooth growth and the relations between its different morphological components is rarely investigated. Seven pelleted diets varying in abrasive size and concentration were fed over a 17-month period to 49 sheep (Ovis aries), of which n = 39 qualified for morphology measurements. Using computed tomography, scans of the skulls were made over the course of the experiment, and the impact of diet-related wear was observed on tooth volume and morphology, including the position of dental burr marks, over time. Digital caliper measurements were applied to 3D renderings of the teeth, and the volume of crown and root segments were investigated separately. We aimed to detect a signal of root growth compensating for wear, and test if this mechanism would be affected by dietary abrasives. Crown-segment volume loss was correlated to root-segment volume gain. Height and burr mark measurements indicated a much higher experimental tooth wear than that previously reported for free-ranging animals. The reason for this is unclear. There was no relationship between tooth height and dentine basin depth. For all parameters, there was no effect of diet; hence, while the measurements corroborate general understanding of tooth wear and compensatory processes, these methods appear not suitable to assess subtle differences between feeding regimes.

The Impact of Canopy Reflectance on the 3D Structure of Individual Trees in a Mediterranean Forest

The characterization of 3D vegetation structures is an important topic, which has been addressed by recent research in remote sensing. The forest inventory requires the proper extraction of accurate structural and functional features of individual trees. This paper presents a novel methodology to study the impact of the canopy reflectance on the 3D tree structure. A heterogeneous natural environment in a Mediterranean forest, in which various tree species (pine, oak and eucalyptus) coexist, was covered using a high-resolution digital camera and a multispectral sensor. These devices were mounted on an Unmanned Aerial Vehicle (UAV) in order to observe the tree architecture and the spectral reflectance at the same time. The Structure from Motion (SfM) method was applied to model the 3D structures using RGB images from the high-resolution camera. The geometric accuracy of the resulting point cloud was validated by georeferencing the study area through multiple ground control points (GCPs). Then, the point cloud was enriched with the reflected light in four narrow-bands (green, near-infrared, red and red-edge). Furthermore, the Normalized Difference Vegetation Index (NDVI) was calculated in order to measure the tree vigor. A comprehensive analysis based on structural and spectral features of individual trees was proposed. A spatial segmentation was developed to detect single-trees in a forest and for each one to identify the crown and trunk. Consequently, structural parameters were extracted, such as the tree height, the diameter at breast height (DBH) and the crown volume. The validation of these measurements was performed by field data, which were taken using a Total Station (TS). In addition, these characteristics were correlated with the mean reflectance in the tree canopy. Regarding the observed tree species, a statistical analysis was carried out to study the impact of reflectance on the 3D tree structure. By applying our method, a more detailed knowledge of forest dynamics can be gained and the impact of available solar irradiance on single-trees can be analyzed.

Показатели роста кедра сибирского разного географического происхождения на подвое сосны обыкновенной

Forests dominated by Siberian pine (Pinus sibirica Du Tour) occupy about 40 mln ha in Russia. They fulfll soil- and water-protective roles, produce oxygen, and are the source of valuable nuts, wood, and other materials. The 36-year-old grafted trees of Siberian pine growing on a hybrid seed plantation in the suburban area of Krasnoyarsk region were the study object. A comparison of growth indices of 36-year-old ramets of Siberian pine of different geographical origin was the research purpose. Graftings were made on the Scots pine young growth in 1982. Grafting stocks were cut from plants grown from seeds harvested in 1960in populations of different geographical origin. The location of the initial populations differs in latitude by 12°, longitude by 64° and altitude by 900 m above sea level. It has been found that the average height of 36-year-old grafted trees depending on geographical origin varies between 12.4 and 15.0 m; the trunk diameter – 29.7 and 40.9 cm; and the crown diameter – 6.4 and 7.6 m. Clones of Tomsk origin are characterized by the best growth. Clones of the northern populations (Komi and Sakha Republics) are characterized by the lowest height. The average diameter of scion exceeds the diameter of rootstock by 6.4–39.7 % depending on the graft geographical origin. Good graft intergrowth (the scion diameter is equal to the rootstock diameter) is observed in 10–27 % of trees. A relationship was found between the grafted trees: close, between trunk and crown diameter (r = 0.855); trunk diameter and crown volume (0.827); signifcant, between trunk diameter and crown length (0.520). It has been established that both the geographical origin and the clone belonging of scion influence on the growth intensity of the grafted trees and intergrouth of the grafted components. The obtained results can be used in creation of clonal plantations of the second generation. For citation: Matveeva R.N., Butorova о.F., Bratilova N.P., Shcherba I.E., Komarnitsky V.V. Growth Indices of Siberian Pine of Different Geographical Origin Grafted on a Scots Pine Rootstock. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 2, pp. 9–19. DOI: 10.37482/0536-1036-2020-2-9-19

Large-eddy simulation of the optimal street-tree layout for pedestrian-level aerosol particle concentrations – A case study from a city-boulevard

Abstract Street vegetation has been found to have both positive and negative impacts on pedestrian-level air quality, but the net effect has remained unclear. In this study, the effect of street trees on aerosol mass (PM10 and PM2.5) and number in a boulevard-type street canyon with high traffic volumes in Helsinki is examined using the large-eddy simulation model PALM. Including a detailed aerosol module and a canopy module to comprise permeable trees, PALM allows to examine the effect of street trees in depth. The main aim is to understand the relative importance of dry deposition and the aerodynamic impact of street trees on the different aerosol measures at pedestrian-level and to find a suitable street-tree layout that would minimise the pedestrian-level aerosol particle concentrations over the boulevard pavements. The layout scenarios were decided together with urban planners who needed science-based knowledge to support the building of new neighbourhoods with boulevard-type streets in Helsinki. Two wind conditions with wind being parallel and perpendicular to the boulevard under neutral atmospheric stratification are examined. Adding street trees to the boulevard increases aerosol particle concentrations on the pavements up to 123%, 72% and 53% for PM10, PM2.5 and total number, respectively. This shows decreased ventilation to be more important for local aerosol particle concentrations than dry deposition on vegetation. This particularly for PM10 and PM2.5 whereas for aerosol number, dominated by small particles, the importance of dry deposition increases. Therefore the studied aerosol measure is important when the effect of vegetation on pedestrian-level air quality is quantified. Crown volume fraction in the street space is one of the main determining factors for elevated mass concentrations on the pavements. The lowest pedestrian-level mass concentrations are seen with three rows of trees of variable height, whereas the lowest number concentrations with four rows of uniform trees. The tree-height variation allows stronger vertical turbulent transport with parallel wind and largest volumetric flow rates with perpendicular wind. Introducing low (height The results show how street trees in a boulevard-type street canyon lead to decreased pedestrian-level air quality with the effect being particularly strong for larger aerosol particles. However, with careful planning of the street vegetation, significant reductions in pedestrian-level aerosol particle concentrations can be obtained.

Twenty-Five Years after Stand Thinning and Repeated Fertilization in Lodgepole Pine Forest: Implications for Tree Growth, Stand Structure, and Carbon Sequestration

Silvicultural practices such as pre-commercial thinning (PCT) and repeated fertilization have been used successfully around the world to increase forest biomass for conventional wood products, biofuels, and carbon sequestration. Two complementary studies were designed to test the hypotheses (H) that large-scale PCT and PCT with repeated fertilization of young (13–17 years old) lodgepole pine (Pinus contorta var. latifolia) stands, at 25 years after the onset of treatments, would enhance (H1) productivity and structural features (diameter and height growth, crown volume and dimensions) of crop trees; (H2) merchantable volume of crop trees, (H3) abundance of understory conifer, herb and shrub layers, and (H4) carbon storage (sequestration) of all layers. Results are from two studies in south-central British Columbia, Canada. The PCT study had three densities: 500, 1000, and 2000 stems/ha, an unthinned, and old-growth stand replicated at three areas. The PCT-FERT study had four densities: 250, 500, 1000, and 2000 stems/ha with and without a repeated fertilization treatment, and an unthinned-unfertilized stand, replicated at two areas. Heavily thinned (≤1000 stems/ha) and fertilized stands generally had larger mean diameters and crown dimensions than lightly thinned or unfertilized stands, whereas mean heights of crop trees remained relatively unaffected, and hence partial support for H1. Despite differences in stand density (4- and 8-fold) of original crop trees, ingress of intermediate crop trees over the 25 years changed density dramatically. There was no support for H2, as mean merchantable volume of total crop trees was similar across stand densities owing to ingress, and was also similar in fertilized and unfertilized stands. In stands thinned to ≤500 trees/ha, there is an anticipated increase in crop tree density of 2.2 to 4.3 times over 25 years compared with the original post-thinning densities. Mean abundance of understory conifers was generally similar among stands owing to successional development towards canopy closure, whereas herbs and shrubs persisted only in canopy gaps in heavily thinned stands, thereby providing no support for H3. Mean carbon storage was similar across densities in both studies with ingress contributing a considerable amount to carbon sequestration at the lower densities. Fertilization increased (1.4 times) mean carbon storage significantly among total crop trees, total conifers, and the grand total of all layers, thereby providing partial support for H4. Thus, much of the potential above-ground carbon storage lost by thinning was restored in the heavily thinned stands at 25 years post-treatment.

The Economy of Canopy Space Occupation and Shade Production in Early- to Late-Successional Temperate Tree Species and Their Relation to Productivity

Light capture is linked to occupation of canopy space by tree crowns, which requires investment of carbon and nutrients. We hypothesize that (i) late-successional trees invest more in casting shade than in occupying space than early-successional trees, and (ii) shade production and crown volume expansion are generally greater in more productive species. For six Central European early-successional (Betula pendula, Pinus sylvestris), mid/late-successional (Quercus petraea, Carpinus betulus), and late-successional tree species (Tilia cordata, Fagus sylvatica), we measured through full-tree harvests (1) crown volume, (2) the costs of canopy space exploration (carbon (C) and nutrients invested to fill crown volume), of space occupation (annual foliage production per volume), and of shade production (foliage needed to reduce light transmittance), and (3) related the costs to aboveground productivity (ANPP). The C and nutrient costs of canopy volume exploration and occupation were independent of the species’ seral stage, but increased with ANPP. In contrast, the cost of shade production decreased from early-to late-successional species, suggesting that the economy of shade production is more decisive for the competitive superiority of late-successional species than the economy of canopy space exploration and occupation.

Intraspecific variation in surface water uptake in a perennial desert shrub

Abstract Despite broad recognition that water is a major limiting factor in arid ecosystems, we lack an empirical understanding of how this resource is shared and distributed among neighbouring plants. Intraspecific variability can further contribute to this variation via divergent life‐history traits, including root architecture. We investigated these questions in the shrub Artemisia tridentata and hypothesized that the ability to access and utilize surface water varies among subspecies and cytotypes. We used an isotope tracer to quantify below‐ground zone of influence in A. tridentata, and tested whether spatial neighbourhood characteristics can alter plant water uptake. We introduced deuterium‐enriched water to the soil in plant interspaces in a common garden experiment and measured deuterium composition of plant stems. We then applied spatially explicit models to test for differential water uptake by A. tridentata, including intermingled populations of three subspecies and two ploidy levels. The results suggest that lateral root functioning in A. tridentata is associated with intraspecific identity and ploidy level. Subspecies adapted to habitats with deep soils generally had a smaller horizontal reach, and polyploid cytotypes were associated with greater water uptake compared to their diploid variants. We also found that plant crown volume was a weak predictor of water uptake, and that neighbourhood crowding had no discernable effect on water uptake. Intraspecific variation in lateral root functioning can lead to differential patterns of resource acquisition, an essential process in arid ecosystems in the contexts of changing climate and seasonal patterns of precipitation. Altogether, we found that lateral root development and activity are more strongly related to genetic variability within A. tridentata than to plant size. Our study highlights how intraspecific variation in life strategies is linked to mechanisms of resource acquisition. A free Plain Language Summary can be found within the Supporting Information of this article.

Analyzing and overcoming the effects of GNSS error on LiDAR based orchard parameters estimation

Currently, 3D point clouds are obtained via LiDAR (Light Detection and Ranging) sensors to compute vegetation parameters to enhance agricultural operations. However, such a point cloud is intrinsically dependent on the GNSS (global navigation satellite system) antenna used to have absolute positioning of the sensor within the grove. Therefore, the error associated with the GNSS receiver is propagated to the LiDAR readings and, thus, to the crown or orchard parameters. In this work, we first describe the error propagation of GNSS over the laser scan measurements. Second, we present our proposal to overcome this effect based only on the LiDAR readings. Such a proposal uses a scan matching approach to reduce the error associated with the GNSS receiver. To accomplish such purpose, we fuse the information from the scan matching estimations with the GNSS measurements. In the experiments, we statistically analyze the dependence of the grove parameters extracted from the 3D point cloud -specifically crown surface area, crown volume, and crown porosity- to the localization error. We carried out 150 trials with positioning errors ranging from 0.01 meters (ground truth) to 2 meters. When using only GNSS as a localization system, the results showed that errors associated with the estimation of vegetation parameters increased more than 100 % when positioning error was equal or bigger than 1 meter. On the other hand, when our proposal was used as a localization system, the results showed that for the same case of 1 meter, the estimation of orchard parameters improved in 20 % overall. However, in lower positioning errors of the GNSS, the estimation of orchard parameters were improved up to 50% overall. These results suggest that our work could lead to better decisions in agricultural operations, which are based on foliar parameter measurements, without the use of external hardware.

Solation of plum scion-rootstock combinations for cultivation in arid conditions of the Northern Caspian sea

Biological features of growth and fruiting of plum varieties of domestic and foreign selection were investigated, on the dwarf basement ВВА-1. It was established that at the age of 4 years the largest parameters of the crown were the trees of the varieties Burbank, Great Blue and Angelina (6.6–7.4 m3), smaller - varieties Bogatyrskaya, Volgograd and Kubanskaya early (3.5–4.2 m3), which allows to place these trees more. According to the speed, there were large-scale combinations of varieties Bogatyrskaya, Volgograd and Angelina, in which flowering was observed in the first year after landing in the garden. The highest productivity from the unit of section area and crown volume, in three years of fruiting, on the basement of the ВВА-1, was allocated varieties Bogatyrskaya, Volgograd and Kubanskaya early, which are suitable for cultivation according to intensive technologies. The maximum weight of the fruit is observed in Angeline variety -79.3 g.

Understanding Tree-to-Tree Variations in Stone Pine (Pinus pinea L.) Cone Production Using Terrestrial Laser Scanner

Kernels found in stone pinecones are of great economic value, often surpassing timber income for most forest owners. Visually evaluating cone production on standing trees is challenging since the cones are located in the sun-exposed part of the crown, and covered by two vegetative shoots. Very few studies were carried out in evaluating how new remote sensing technologies such as terrestrial laser scanners (TLS) can be used in assessing cone production, or in trying to explain the tree-to-tree variability within a given stand. Using data from 129 trees in 26 plots located in the Spanish Northern Plateau, the gain observed by using TLS data when compared to traditional inventory data in predicting the presence, the number, and the average weight of the cones in an individual tree was evaluated. The models using TLS-derived metrics consistently showed better fit statistics, when compared to models using traditional inventory data pertaining to site and tree levels. Crown dimensions such as projected crown area and crown volume, crown density, and crown asymmetry were the key TLS-derived drivers in understanding the variability in inter-tree cone production. These results underline the importance of crown characteristics in assessing cone production in stone pine. Moreover, as cone production (number of cones and average weight) is higher in crowns with lower density, the use of crown pruning, abandoned over 30 years ago, might be the key to increasing production in combination with stand density management.

AN ELECTRONIC EXCEL-CALCULATOR FOR CALCULATING DENTAL CROWN VOLUMES

Previous studies have found that with increasing volume of hard tissues defect, the sensitivity of the restored structure to the physical and mechanical restoration characteristics is increasing too. Since existing volume determination techniques cannot be use in a clinical setting, this gives reason to consider the problem of volume determination dental hard tissue defects extremely important, and this research-relevant.
 Aims of research. Develop and evaluate the possibility of using methods to determine dental crown volumes and volumes of defects in hard tooth tissue.
 Materials and methods of research. For determination of crown volumes and defect volumes of hard tooth tissues for each group of teeth were used appropriate geometric models. Together with the built models, were performed the mathematical calculations to calculate their linear dimensions.
 Results of the research. We have developed and substantiated the feasibility of using an electronic Excel calculator to calculate dental crown volumes in clinical settings.
 Conclusions. Using our electronic Excel calculator to calculate tooth crown volumes and methods for determining the volume of dental hard tissue defects, in clinical settings we can objectify the diagnostic process in the presence of dental hard tissue defects.

Differential drought resistance strategies of co-existing woodland species enduring the long rainless Eastern Mediterranean summer.

In anticipation of a drier climate and to project future changes in forest dynamics, it is imperative to understand species-specific differences in drought resistance. The objectives of this study were to form a comprehensive understanding of the drought resistance strategies adopted by Eastern Mediterranean woodland species, and to elaborate specific ecophysiological traits that can explain the observed variation in survival among these species. We examined leaf water potential (𝛹), gas exchange and stem hydraulics during 2-3years in mature individuals of the key woody species Phillyrea latifolia L., Pistacia lentiscus L. and Quercus calliprinos Webb that co-exist in a dry woodland experiencing ~ 6 rainless summer months. As compared with the other two similarly functioning species, Phillyrea displayed considerably lower 𝛹 (minimum 𝛹 of -8.7MPa in Phillyrea vs -4.2MPa in Pistacia and Quercus), lower 𝛹 at stomatal closure and lower leaf turgor loss point (𝛹TLP ), but reduced hydraulic vulnerability and wider safety margins. Notably, Phillyrea allowed 𝛹 to drop below 𝛹TLP under severe drought, whereas the other two species maintained positive turgor. These results indicate that Phillyrea adopted a more anisohydric drought resistance strategy, while Pistacia and Quercus exhibited a more isohydric strategy and probably relied on deeper water reserves. Unlike the two relatively isohydric species, Phillyrea reached complete stomatal closure at the end of the dry summer. Despite assessing a large number of physiological traits, none of them could be directly related to tree mortality. Higher mortality was observed for Quercus than for the other two species, which may result from higher water consumption due to its 2.5-10 times larger crown volume. The observed patterns suggest that similar levels of drought resistance in terms of survival can be achieved via different drought resistance strategies. Conversely, similar resistance strategies in terms of isohydricity can lead to different levels of vulnerability to extreme drought.

An efficient RGB-UAV-based platform for field almond tree phenotyping: 3-D architecture and flowering traits

BackgroundAlmond is an emerging crop due to the health benefits of almond consumption including nutritional, anti-inflammatory, and hypocholesterolaemia properties. Traditional almond producers were concentrated in California, Australia, and Mediterranean countries. However, almond is currently present in more than 50 countries due to breeding programs have modernized almond orchards by developing new varieties with improved traits related to late flowering (to reduce the risk of damage caused by late frosts) and tree architecture. Almond tree architecture and flowering are acquired and evaluated through intensive field labour for breeders. Flowering detection has traditionally been a very challenging objective. To our knowledge, there is no published information about monitoring of the tree flowering dynamics of a crop at the field scale by using color information from photogrammetric 3D point clouds and OBIA. As an alternative, a procedure based on the generation of colored photogrammetric point clouds using a low cost (RGB) camera on-board an unmanned aerial vehicle (UAV), and an semi-automatic object based image analysis (OBIA) algorithm was created for monitoring the flower density and flowering period of every almond tree in the framework of two almond phenotypic trials with different planting dates.ResultsOur method was useful for detecting the phenotypic variability of every almond variety by mapping and quantifying every tree height and volume as well as the flowering dynamics and flower density. There was a high level of agreement among the tree height, flower density, and blooming calendar derived from our procedure on both fields with the ones created from on-ground measured data. Some of the almond varieties showed a significant linear fit between its crown volume and their yield.ConclusionsOur findings could help breeders and researchers to reduce the gap between phenomics and genomics by generating accurate almond tree information in an efficient, non-destructive, and inexpensive way. The method described is also useful for data mining to select the most promising accessions, making it possible to assess specific multi-criteria ranking varieties, which are one of the main tools for breeders.

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

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).

Potential of Some Forage Shrubs for Improving Degraded Rangelands Using Compost in Northwestern Coast of Egypt

The northwestern coast of Egypt is one of the most important grazing areas in the country, with a natural rangelands area of about 2.3 million hectares. Rangelands in this area have been facing overgrazing and mismanagement for years, so rehabilitation and restoration approaches are urgently needed for the sustainable development of these rangelands. Hence, this research was conducted at Wadi El-Washka, El- Kaser Region, Northwestern Coast, Marsa Matrouh Governorate, Egypt, in 2017 and 2018 growing seasons to study the effect of compost manure rates on the growth parameters of three forages shrubs species. The experimental design of the experiment was split-plot design with four replications. The main plots included the three shrubs species (Medicago arborea, Periploca angustipholia, and Atriplex nummularia), while compost rates (0, 5, and 10 t/fed) in the subplot. The results concluded that the different shrubs significantly differed under increasing the rate of compost manure. In this respect fertilizing Atriplex nummularia by addition compost at the rate of 10 t/fed as organic manure increased all growth characters including, shrub height of 119.40 and 126.08 cm, number of branches/plants of 11.08 and 11.73 branches, crown coverage of 0.929 and 0.506 m2 and crown volume of 0.363 and 0.260 m3 in spring and autumn growing seasons of 2017 and 2018, respectively under study conditions at northwestern coast of Marsa Matrouh Governorate, Egypt. These findings would have management implications for the better use of untraditional water resources for the sustainable development of degraded desert rangelands

Accelerated formation of Siberian pine (Pinus sibirica Du Tour) stands: a case study from Siberia

Under natural conditions, Siberian pine Pinus sibirica begins to produce commercial cone yields of nuts relatively late (after more than 100 years). The aim of this study was to summarise the experience of the directed formation of Siberian pine forests in Siberia. Experimental objects included plots with traditional thinning of varying intensity and frequency as well as chemical treatment. We assessed the parameters of the stand and its seed production dynamics. Only stands with a minimum density (395–435 trees·ha–1) had a normal seed production energy (1.5 or more cones per shoot). Over-dense stands (830–930 trees·ha–1) were characterised by a low seed production energy (two times or more below the threshold value). In all plots, there were Siberian pine trees with absent or unacceptable seed production energy, which should be removed (DBH up to 28 cm). Seed production energy positively correlated with most tree parameters (age, height, diameter, volume, length and width of crown).