Crown Density Research Articles

The Control Efficacy of Sodium Hypochlorite against Violet Root Rot Caused by Helicobasidium mompa in Apple.

Our study was carried out to determine the control efficacy of sodium hypochlorite (NaOCl) for violet root rot caused by Helicobasidium mompa in apple. The experiment was conducted in the farm located at Chungbuk province in South Korea from 2014 to 2016. When infected apple trees were treated at least two or three times with 31.25 and 62.5 ml/l available chlorine content in NaOCl, it greatly increased the rooting of rootstock, and restored the tree crown density by 44.4–60.5%. In addition, the number of commercial fruit setting was increased by 54.3–64.5%, and the total starch content in shoots was significantly higher than other non-treated apple trees. However, the untreated disease control and thiophanate-methyl WP treated trees showed the symptom of dieback. Therefore, our results indicate that the drenching treatment of NaOCl with 31.25–62.5 ml/l available chlorine content more than two times from late fall to early spring could effectively control the violet root rot and recover tree vigor up to 60%.

Forage production and persistence characteristics of grazed native warm‐season grass mixtures with or without nitrogen fertilizer

AbstractBackgroundNative warm‐season grass (NWSG) mixtures may provide a low‐nitrogen (N)‐input summer perennial forage option to extensively managed forage–livestock systems.MethodsMixed pastures of big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium Michx.), and indiangrass (Sorghastrum nutans L.) fertilized with 0 or 67 kg N ha−1 were continuously stocked with beef heifers and cows. Forage mass, nutritive value, and canopy heights were determined every 2 weeks during the grazing season. Stand persistence measures included the canopy cover and leaf area index (LAI) and plant crown density at spring emergence following 3 years of grazing management.ResultsForage mass, canopy height, and stocking densities were greater for N‐fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3‐year study. Forage NWSG fertilized with N had a greater decrease in LAI during the growing season (51% decrease) than unfertilized NWSG. Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.ConclusionsForage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low‐level N than zero‐N‐input systems and may provide a low‐N‐input alternative for improved species use in southeastern US forage–livestock systems.

Is an Unmanned Aerial Vehicle (UAV) Suitable for Extracting the Stand Parameters of Inaccessible Underground Forests of Karst Tiankeng?

Unmanned aerial vehicle (UAV) remote sensing technology is gradually playing a role alternative to traditional field survey methods in monitoring plant functional traits of forest ecology. Few studies focused on monitoring functional trait ecology of underground forests of inaccessible negative terrain with UAV. The underground forests of tiankeng were discovered and are known as the inaccessible precious ecological refugia of extreme negative terrain. The aim of this research proposal is to explore the suitability of UAV technology for extracting the stand parameters of underground forests’ functional traits in karst tiankeng. Based on the multi-scale segmentation algorithm and object-oriented classification method, the canopy parameters (crown width and densities) of underground forests in degraded karst tiankeng were extracted by UAV remote sensing image data and appropriate features collection. First, a multi-scale segmentation algorithm was applied to attain the optimal segmentation scale to obtain the single wood canopy. Second, feature space optimization was used to construct the optimal feature space set for the image and then the k-nearest neighbor(k-NN) classifier was used to classify the image features. The features were classified into five types: canopy, grassland, road, gap, and bare land. Finally, both the crown densities and average crown width of the trees were calculated, and their accuracy were verified. The results showed that overall accuracy of object-oriented image feature classification was 85.60%, with 0.72 of kappa coefficient. The accuracy of tree canopy density extraction was 82.34%, for which kappa coefficient reached 0.91. The average canopy width of trees in the samples from the tiankeng-inside was 5.38 m, while that of the outside samples was 4.83 m. In conclusion, the canopy parameters in karst tiankeng were higher than those outside the tiankeng. Stand parameters extraction of karst tiankeng underground forests based on UAV remote sensing was relatively satisfactory. Thus, UAV technology provides a new approach to explore forest resources in inaccessible negative terrain such as karst tiankengs. In the future, we need to consider UAVs with more bands of cameras to extract more plant functional traits to promote the application of UAV for underground forest ecology research of more inaccessible negative terrain.

Morphological pattern of the dermal denticles of the Southern sawtail catshark Galeus mincaronei Soto, 2001.

Dermal denticles cover the skin of sharks for protection and may have additional functions, depending on the environment. The aim of the present study was to analyze the morphological pattern of dermal denticles across the body of the poorly known deep-water catshark Galeus mincaronei, which is endemic to Southern Brazil. Additionally, we aimed to identify differences between sexes and stages of sexual maturity. For this purpose, we analyzed patches of eight skin samples from body regions, that is, the head, body, and tail. Dermal denticles were imaged using scanning electron microscopy. Measurements of crown morphological variations (length and width) and density of dermal denticles were performed. Nine characters of dermal denticle morphology were selected to describe a morphological pattern using principal component analysis (PCA). The first PCA axis explained 45.2% of the variation, the second explained 33%, and the third explained 14.3%, together explaining 92.5% of the total variation in denticle morphology. We identified three groups of dermal denticle crown morphologies and their possible functions. The first was composed of nostril and snout denticles, which might suggest abrasion strength functions; the second was composed of most body denticles, such as those in the cranium, on the left side of the body, and on the pectoral, dorsal, and caudal fins, which might be related to generalized functions; and the third was composed of only caudal crest denticles, which might indicate defense functions with hydrodynamic properties in G. mincaronei. Likewise, our results reveal variations in dermal denticle morphology and arrangement along the three maturity stages considered in both sexes. Similarly, sexual dimorphism in the crown width and morphology of dermal denticles was observed in developing and mature individuals. Our results are the first to reveal the morphological variation of dermal denticles in relation to function, sex, and ontogeny of individual G. mincaronei.

Canopy condition: Health indicator of urban trees in the San Juan de Aragón Forest, Mexico City

Urban green areas provide various services to society and the environment. The Bosque San Juan de Aragón is one of the few green areas in the northeast of Mexico City and the current condition of its trees in terms of health is not known with precision. In the present study, the protocol for the crown condition indicator was implemented and adapted in 28 circular plots of 0.1 ha, randomly established in the aforementioned forest. All trees within each plot were measured for normal diameter (ND) and total height (TA), and their taxonomic classification, crown condition and plantation density were determined. For crown condition, six variables were measured: proportion of live crown (PLC), crown density (CD), crown transparency (CTR), dieback (DB), crown position (CP) and light exposure (LE). The first four were measured in 5% classes and the remaining two were measured on an ordinal scale. A total of 760 trees were evaluated, grouped into 10 families, 11 genera and 12 species. The average values for the crown variables were 56.37% PLC, 44.38% CD, 4.04% DB and 38.4% CTR. Only PLC reached the established standards of tree health found in other studies, while CD was low and CTR and DB values were high.

Cenopopulation of Epipactis helleborine (Orchidaceae) in forest ecosystems that have been anthropogenically transformed to various degrees

Because of developed symbiotic connections of the root system of trees, mycorrhiza-forming fungi and the orchid family Orchidaceae in forest ecosystems of the northeast Polissia Region – cultivated Pinus sylvestris, which are now 100–120 years old, recovery of cenopopulations of Epipactis helleborine has been observed in locations of mixed and broad-leaved forests. In natural plant cover of mature pines of the region, indigenous vegetation is gradually recovering – there occur young Quercus robur, Tilia cordata, Acer platanoides of various ages, crown density of understory formed by Coryllus avellana has reached 0.6, above-ground organic leaf foliage that is able to sustain moisture and increase fertility of soil accumulates, creating sufficient conditions of shading for seedlings and juvenile individuals of forest orchids. Special studies revealed a relationship between density of E. helleborine specimens and crown density of the tree stand, shrub strata, structure of soil cover, expressed in cenoses under various degrees of recreational pressure. Density of individuals of forest orchids in the studied populations ranges 10.0 to 0.1 ind./10 m2. Dynamics were seen in groupings of Betuleto-Pineta corylosa, Querceta (roboris) corylosa, Querceto-Pineta corylosa, Acereto (platanoidis) –Tilieto (cordatae) – Quercetum (roboris) aegopodiosum in the territory of the nature-reserve fund and structurally similar anthropogenically pressurized cenoses. We determined that all examined cenopopulations in old indigenous zonal cenoses in the territory of the nature reserve fund are normal, they may be considered relatively stable, ontogenetic spectra are incomplete, mostly with right-sided age spectrum – maximum numbers of virgin and generative individuals of various stages. Low density of individuals and incomplete spectra of cenopopulations in light oak forests are natural, and now the largest share of generative and virgin individuals is concentrated in this area. Impact of recreation, unavoidable due to proximity to a road, is a negative factor directly decreasing their density. Ontogenetic spectra of all cenopopulations are incomplete – no seedlings were found in the natural conditions due to underground type of germination. Much more interesting data may be obtained by monitoring studies of age and morphometric dynamic changes during several years.

SGOT: A Simplified Geometric-Optical Model for Crown Scene Components Modeling over Rugged Terrain

Topography affects the fraction of scene components of the canopy and background, resulting in the observed reflectance distortion. Modeling the canopy reflectance over rugged terrain needs to account for topographic effects. For this purpose, the existing models greatly increased the mathematical complexity while improving description of terrain and crown structure, which dramatically decreased the computational efficiency so as to limit their universal application. In this study, we developed a simplified geometric-optical model (SGOT) for simulating the scene components over rugged terrain. The geotropism of tree growth was considered to make SGOT physically sound. The internal structure of crown was simplified to make SGOT mathematically simpler. Scene component observations derived from Persistence of Vision Ray-tracer (POV-Ray) on surfaces with different normal directions and simulations were made using Geometric-Optical and Mutual Shadowing Coupled with Topography Model (GOMST) and Geometric-Optical for Sloping Terrains Model GOST; models were combined to test the SGOT model. In addition, topographic factors and crown density effect on the scene components modeling were analyzed. The results indicated that SGOT has good accuracy (R2 for the areal proportions of sunlit crown (Kc), sunlit background (Kg), shaded crown (Kt), and shaded background (Kz) are 0.853, 0.857, 0.914, and 0.838, respectively) compared with POV-Ray simulation, and performs better than GOMST, especially in scenes with high crown density. Moreover, SGOT outperformed the compared models in computational efficiency (4% faster than GOMST and 29.5% faster than GOST). Finally, the simulations of the scene components distribution in different topographic factors and crown density were further discussed. SGOT and GOST can both capture scene component variations caused by terrain better than GOMST, but comparatively, SGOT provides a more efficient tool to simulate the crown scene components because of its physical soundness and mathematical simplicity, and consequently, it will facilitate the modeling of canopy reflectance over mountainous regions.

Почвенные характеристики эмбриоземов под покровом сосновых насаждений на техногенных элювиях Кузбасса

The article studies the edificatory role of pine growing on the technogenic landscapes of the Kuznetsk coal basin and considers the influence of plantations of Scots pine (Pinus sylvestris L.) with different crown density on the main characteristics of embryozems on the overburden dumps of the coal mining industry. The object of the study was soil samples collected in various zones of the phytogenic fields of pine growing on the transport-free dump of the Kedrovsky coal mine. When choosing test plots, the plantations were ranked according to crown density into unclosed (crown density about 30 %), medium-closed (about 60 %) and closed (about 90 %). In each gradation of closeness, the following zones of influence (phytogenic fields) of trees were identified: undercrown, near-crown (intermediate). The selection of sampling points was carried out taking into account the presence of the identification signs: solid pine litter (undercrown zone), developed moss cover (near-crown zone) and developed meadow vegetation (outer zone). External zones are not found in unclosed and medium-closed plantations. In total, according to the degree of crown density and zoning of phytogenic fields, 7 plantation sites of Pinus sylvestris were identified. Soil samples were taken at each of them from a depth of 0–20 cm in the 3rd decade of September. The enzyme activity was studied in recently collected soil in in 3-fold replications. The fractional composition of soils and their agrochemical properties were determined in dried soil on the basis of the Center for Agrochemical Service “Kemerovo”. The analysis of the results showed that pine stands contribute to accelerated disintegration of technogenic residual rocks with the formation of fine-grained fractions, which are of great soil and environmental importance. Litter combined with grassy vegetation in open pine stands favors the accumulation of total nitrogen in embryozems. It was revealed that the content of readily available forms of phosphorus and potassium depends on lithogenic rather than phytocenotic factors. The study of the enzymatic activity of soils showed that the phosphatase activity decreases with an increase in the phosphorus content, and the protease activity increases with an increase in the nitrogen content. Agrochemical indicators of embryozems are favorable for the growth of herbaceous plants due to horizontal differentiation of space under the influence of stands of Scots pine.

Морфологические показатели крон лещины в горных лесах

Common hazel is valuable for its nutritional and medicinal properties and its ability to provide soil conservation functions. However, the morphological characteristics of this plant have not been studied sufficiently. The research purpose is to identify features of significant morphological characteristics of crowns of nut-bearing hazel plants, to assess the biological diversity of these characteristics at different heights, under the forest canopy and on the glades for further detection of forestry and ecological functions of this plant, and to select ornamental and other economically valuable forms. The nut-bearing hazel plants growing in the mountain forests of the North-Western Caucasus at the altitude of 450–600 and 1,300–1,500 m above the sea level under the forest canopy and on the glades were the objects of the research. We studied the diameters of the central and three largest trunks, the crown and the base of the bush, its height, the number of shoots up to 4 years old and older, the total number of shoots in the bush, the density and shape of the crown. We examined 200 ramets that had entered the fruiting stage. The diversity index was calculated according to the authors’ method (Sukhorukikh-Biganova). At the altitudes of 1,300–1,500 m above the sea level, under better humidification compared to the sites located at the altitude of 450–600 m, hazel has statistically reliable better development of average diameters of the central and three main trunks and crown, higher total number of shoots up to 4 years old and older. Hazel trees have superior crown and bush base diameters, greater number of shoots up to 4 years old and older, the total number of shoots in the bush on the glades in conditions of good light compared to those under the forest canopy. Here the plants are more likely to form bushes with a spreading and thick crown. The upper sites showed a significantly higher diversity index for the average diameter of the three largest trunks of the hazel bush and the highest number of shoots older than 4 years. There is a significantly superior difference in the morphological diversity index for the average diameter of the bush base, the number of shoots up to 4 years old and older, the total number of shoots, and crown density on the glades compared to the sites under the forest canopy. In terms of crown shape, the diversity index is higher under the forest canopy than on the glade. The generalized indices of diversity of quantitative, qualitative and general morphological characteristics of hazel bushes did not differ significantly at different heights, under forest canopy and on the glades.

Bulk Density of Shrub Types and Tree Crowns to Use with Forest Inventories in the Iberian Peninsula

Bulk density for shrubs and tree crowns is an important variable, useful for many purposes, namely estimations for biomass and carbon sequestration and potential fire behavior prediction. In the latter case, bulk density is required to predict the rate of spread and intensity of crown fires. However, bulk density information is scarce. The estimation of bulk density is crucial to help choosing proper pyrosilviculture options to decrease fire susceptibility. Due to the similar environmental conditions and fuel characteristics in Portugal and Spain, we modelled bulk density for the most common woody species in all the Iberian Peninsula. We used 10 different shrub type formations and a set of tree species or groups common to both countries. Equations for bulk density, in both forest canopy and understory layers, were fitted as a function of biometric variables commonly used in forest inventories for the selected species. Standardized estimates of bulk density can be associated with data from the National Forest Inventories from Portugal and Spain, to estimate biomass of the forest ecosystems and to evaluate potential fire behavior involving tree canopies and shrubs.

The content of photosynthetic pigments in the leaves of «healthy» and «weakened» balsam poplar trees (<i>Populus balsamifera</i> L.) growing under conditions of industrial pollution (Republic of Bashkortostan, Sterlitamak industrial center)

The paper presents the results of studies on the assessment of the relative vitality of balsam poplar ( Populus balsamifera L.) plantations under the conditions of polymetallic pollution of the Sterlitamak Industrial Center (SIC). Poplar plantations of the sanitary protection zone of the SPC are classified as weakened. External signs of oppression are manifested in a decrease in crown density, an increase in the number of dead branches, damage to the assimilation apparatus by chlorosis and necrosis. Trees belonging to the healthy category grow in the plantations. It was shown that the average content of chlorophylls ( a + b ) in the leaves of healthy poplar trees varied from 25,0 to 28,0 g/cm of fresh weight, while in weakened trees it was relatively low and amounted to 17,2-22,6 g/cm wet weight. The decrease in the total content of chlorophylls and the deterioration in the relative vitality of trees are interrelated. It has been established that during the period of active leaf growth (in June and early July), a high content of chlorophylls and nitrogen balance index (NBI) is noted in the leaves of both healthy and weakened balsam poplar trees. The relationship of the indicators under consideration is confirmed by the regression equations of the polynomial function ( y = -2,15x + 8,05x + 23,2 ; y = -2,35x + 8,75x + 19,9 for the leaves of healthy trees; y = -3,1x + 11,1x +13,4 ; y = -3,9x + 14,1x + 10 for the leaves of weakened trees), as well as determination coefficients (R = 1 for the leaves of healthy trees; R = 1 for the leaves of weakened trees). The maximum differences in the ratio of chlorophyll content ( a + b ) and nitrogen balance in the leaves of healthy and weakened poplar trees were noted at the end of August. During the growing season, in the leaves of weakened trees, compared with the leaves of healthy poplar trees, a decrease in the values NBI and the content of chlorophylls is observed. At the same time, there are no significant changes in the content of chlorophylls on the adaxial and abaxial sides of the leaves of healthy and weakened balsam poplar trees during the growing season.

Complementary effects of tree species on canopy rainfall partitioning: New insights for ecological restoration in Andean ecosystems

Vegetation affects local water balance partitioning via effects on incoming precipitation, local radiation balance and soil hydrological properties. The extent of these effects is related to plant functional traits, such that forest composition plays an important role in its hydrological function. Therefore, the selection of species in forest restoration processes is key to recovering ecological (including hydrological) function. However, most restoration projects often do not include functional criteria for species selection, and even less frequently they include ecohydrological functions, although many projects are intended to recover hydrological regulation. We explored the association between plant functional traits and ecohydrological function, indicated by precipitation partitioning in the canopy into stemflow and throughfall, in an 8-year watershed restoration project in the Central Andes of Colombia. We monitored stemflow and throughfall (both mean and variability) on planted individuals from ten native tree species for almost two years and measured functional traits that describe tree crowns and are associated with rainfall partitioning. We found that stemflow and throughfall behavior is generally inverse and differ among species, with the highest variability in mean stemflow and coefficient of variation of throughfall. Furthermore, our results show that stemflow and throughfall are significantly associated with tree crown functional traits (R2 = 0.74 for crown area and R2 = 0.62 for crown density × volume). Besides, the studied species are organized in a variation space of ecohydrological processes and crown functional traits (first two principal components from PCA explain 71.7% of data variability). They are organized from wider/less dense crowns in Alnus acuminata to smaller/denser crowns in Quercus humboldtii, which significantly influenced the temporal variability of stemflow and throughfall, respectively. Other species are located intermittently along this variation space. From a multivariate perspective, our species were differentiated into four discrete groups based on similar functional traits and, therefore, with similar effects on ecohydrological processes. This suggests a complementary effect of different species on the ecosystem hydrological functions, thus highlighting the importance of considering diversity on ecosystem management and ecological restoration for the recovery of ecosystem integrity.

Tree crown segmentation in three dimensions using density models derived from airborne laser scanning

ABSTRACT This article describes algorithms to extract tree crowns using two-dimensional (2D) and three-dimensional (3D) segmentation. As a first step, a 2D-search detected the tallest trees but was unable to detect trees located below other trees. However, a 3D-search for local maxima of model fits could be used in a second step to detect trees also in lower canopy layers. We compared tree detection results from ALS carried out at 1450 m above ground level (high altitude) and tree detection results from ALS carried out at 150 m above ground level (low altitude). For validation, we used manual measurements of trees in ten large field plots, each with an 80 m diameter, in a hemiboreal forest in Sweden (lat. 58°28' N, long. 13°38' E). In order to measure the effect of using algorithms with different computational costs, we validated the tree detection from the 2D segmentation step and compared the results with the 2D segmentation followed by 3D segmentation of the ALS point cloud. When applying 2D segmentation only, the algorithm detected 87% of the trees measured in the field using high-altitude ALS data; the detection rate increased to 91% using low-altitude ALS data. However, when applying 3D segmentation as well, the algorithm detected 92% of the trees measured in the field using high-altitude ALS data; the detection rate increased to 99% using low-altitude ALS data. For all combinations of algorithms and data resolutions, undetected trees accounted for, on average, 0–5% of the total stem volume in the field plots. The 3D tree crown segmentation, which was using crown density models, made it possible to detect a large percentage of trees in multi-layered forests, compared with using only a 2D segmentation method.

Использование зимних и ранневесенних космоснимков для оценки проективного покрытия березняков на залежах

More than 40 million hectares of agricultural land were abandoned after the collapse of the Soviet Union. A significant part of the land is covered by spontaneously regenerating woody and shrubby vegetation. When identifying the forest regeneration, the stands with a tree cover of more than 50% are accurately identified. It is difficult to identify the initial stages of forest regeneration on the abandoned agricultural lands using summer satellite images because of little difference between the young trees and saplings due to their low height and low density on the one hand, and herbaceous vegetation on the other. The purpose of this work was to apply winter and early-spring satellite images for assessments of the tree cover of birch-dominated stands (Betula pen-dula Roth.) formed on the abandoned agricultural lands (See Fig. 1). We used 189 releves of birch forests on the abandoned agricultural lands in the broad-leaved forest zone of the Republic of Bashkortostan. A regression analysis of the evaluation of the tree cover was carried out using the values of the spectral reflectance of the RED, NIR, SWIR11, and SWIR12 bands, as well as the values of the NDFSI snow index from seven cloudless Sentinel-2 images taken between 04.11.2020 and 13.05.2021 (See Fig. 2, 3). When selecting optimal regression models, the values of correlation coefficients (R) and determination coefficients (R2) were used to assess the model quality. To test the possibility of using the obtained models for assessing the tree cover of the stand at earlier succession stages, we involved the data on the tree cover from 36 geobotanical releves, where the crown density of the stand was visually evaluated in July 2013. Then, the described procedure was applied to calculate the tree cover using the Landsat-8 image taken on 25.03.2014. When creating regression models to calculate the tree cover, the best results were obtained using the red band of early spring images during the period when snowpack is still solid (from mid-March to the first half of April) (See Table 1). The correlation between the tree cover and the spectral reflectance of the red band was -0.90. The model allowed us to determine accurately the tree cover of birch forests aged from 18 to 20 years which prevail in the zone of broad-leaved forests in the Republic of Bashkortostan. The accuracy of the model for determining the tree cover according to the obtained regression models for other dates is unstable and highly likely influenced by the snow depth and the seasonal dynamics of changes in the radiation intensity of the red and infrared bands (See Table 2, 3). To conclude, the equations calculated from modern satellite images can be used to assess the tree cover using retrospective images at earlier succession stages of the abandoned field recovery. When using early-spring images, the snow depth should be taken into account since the snowpack melting dates can vary greatly from year to year. The paper contains 3 Figures, 3 Tables, and 41 References. The Authors declare no conflict of interest.

Reduction of Noise Pollution with the Help of Roadside Collections in Coimbatore and Surroundings

Noise is the excessive and unwarranted sound that creates discomposure to human beings and abruptly disrupts the quality of the environment. The noise is magnified by the intensity of the sound produced at a particular place and is measured in decibels (dB). The noise pollution is mainly caused by the transportation of road, rail, airways and industrial activities. Increased growth and development of the cities marks the predominant source for the road travel of the people. The road traffic in main cities becomes part and parcel of life because everyone contributes to the self and development of society as a growing concern for the community. Green energy usually absorbs and disintegrates the excess noise and air pollutants that divine has given us through green belts. Therefore, the green belts helps in the natural source of noise and air pollutant reduction. The potentialities of the greenbelts are laid along the road-sides have been assessed in Coimbatore, Tamil Nadu at various selected places. Reduction of noise level was achieved up to 14 dB under the green belt area while compared to the open area. An area with a higher crown density demonstrated a lower noise level than the area with a lower crown density.

Application of a Panel Data Quantile-Regression Model to the Dynamics of Carbon Sequestration in Pinus kesiya var. langbianensis Natural Forests

Even though studies on forest carbon storage are relatively mature, dynamic changes in carbon sequestration have been insufficiently researched. Therefore, we used panel data from 81 Pinus kesiya var. langbianensis forest sample plots measured on three occasions to build an ordinary regression model and a quantile-regression model to estimate carbon sequestration over time. In the models, the average carbon reserve of the natural forests was taken as the dependent variable and the average diameter at breast height (DBH), crown density, and altitude as independent variables. The effects of the DBH and crown density on the average carbon storage differed considerably among different age groups and with time, while the effect of altitude had a relatively insignificant influence. Compared with the ordinary model, the quantile-regression model was more accurate in residual and predictive analyses and removed large errors generated by the ordinary model in fitting for young-aged and over-mature forests. We are the first to introduce panel-data-based modeling to forestry research, and it appears to provide a new solution to better grasp change laws for forest carbon sequestration.

Standing Crop Biomass and Carbon Content of Mangrove Avicennia marina (Forssk.) Vierh. along the Red Sea Coast of Saudi Arabia

A number of Avicennia marina mangrove forests exist along the 1134 km stretch of the Saudi Red Sea coast. Three areas, one in each of the north, centre, and south of the coast, were selected for this investigation into the relationship between total biomass (above-ground, AGB, and below-ground, BGB), and biomass carbon stocks of A. marina, along the nutrient availability (combined with a salinity gradient). To estimate the total biomass stock, this research employed equations formulated through a regression approach. Various population characteristics (tree crown diameter, height, and density) and measurements of carbon (C) in the trees were captured, and other measurements were gathered to represent the environmental properties: electrical conductivity (EC), total dissolved solids (TDS), and total phosphorus (TP) and total nitrogen (TN) levels. With this data from the 21 stands and 7 sites of A. marina covered by the three locations chosen along the coast, it was concluded that a discernible influence is exerted by the concentrations of TP and TN in the sea water and sediments over the population characteristics of this plant. The resulting estimates also demonstrated a steady increase in total biomass and total biomass carbon storage from the mangroves in the north toward the south, with values changing overall from 197.9 to 1188.2 Mg DM ha−1 and from 87.6 to 412.5 Mg C ha−1 respectively. This illustrates that the biomasses held by the southern mangroves are 6 times (total) and 4.7 times (total carbon storage) higher than those in the north.

THE EFFECT OF TREE CANOPY STRUCTURE ON SPATIAL RAINFALL REDISTRIBUTION DURING POST-ERUPTION RECOVERY OF MOUNT MERAPI, JAVA ISLAND

The tree canopy around Merapi Volcano, Yogyakarta, Indonesia, has a unique structure. The frequency of volcanic eruptions influences the uniqueness of the structure, as it is a response to volcanic ash and rainfall characteristics. This research was conducted on eight species that have different canopy structures. In contrast to the trees canopy that was not affected by eruptions, the tree canopy around the Volcano has more dynamic canopy surface characteristics during the recovery period. The redistribution of rainfall in the tree canopy was traced by calculating unit area discharge and droplets' probability in each canopy structure segment. The results of empirical throughfall calculation and throughfall direct observation were tested using ANOVA. Most of the throughfall occurs simultaneously under the canopy during rain with a depth of 3.5 - 72.5 mm or intensity of 10 - 20 mm/hour (observed = 58% and empirical = 57%). The existing range of rainfall intensity or rainfall depth shows that the process of redistribution of rainfall in the canopy has time constraints and canopy storage capacity constrain. The canopy surface characteristics have a more significant effect than the canopy structure on the redistribution of rainfall. The canopy surface serves as a sheet of rainfall concentration to the next section. The important canopy surface structure parameters to rainfall concentration are leaves characteristics, branches stiffness, and crown density. Knowledge of the tree canopy's rainfall flow distribution process will help manage conservation-based rehabilitation activities in areas prone to volcanic disasters.

Analysis of the vitality of the Agathis dammara tree at Situ Gunung Resort, Gunung Gede Pangrango National Park

Vitality is the vigor value of the trees in responding to environmental conditions. Determined vitality value was by calculating tree damage and crown condition. The Agathis dammara tree is a native Indonesian plant in the Situ Gunung Resort, Gunung Gede Pangrango National Park (TNGGP). This study aims to determine the vitality and value of the health status of Agathis dammara trees at Situ Gunung Resort, TNGGP. The research location is in the utilization zone at the Situ Gunung Resort, TNGGP, covering an area of 700 haBuilt observation plots based on the Forest Health Monitoring (FHM) cluster plot design as many as nine cluster plots. They have calculated tree damage based on the location where found the damage was in the FHM method. Calculated condition canopy based on five parameters visual crown. Assessment of tree health status uses a forest health assessment information system. The results showed that the location where found the most damage was at the root and lower stem (code 2) as many as 67 trees, dominated by liana damage (code 20) as many as 43 trees, with an average damage level of 35%. The live crown ratio 20-35%, crown density 25-50%, foliage transparency 50-70%, crown diameter 2.5-10 m, and dieback 0-5%. The value of the health status of the Agathis dammara tree has a value of 1.69-2.44. Thus, these conditions illustrate that the vitality and value of the health status of Agathis dammara trees at Situ Gunung Resort, TNGGP are in the medium criteria and category.

Thermal environment analysis of landscape parameters of an urban park in summer - A case study in Suwon, Republic of Korea

Urban parks are becoming increasingly important for improving urban thermal environments. To investigate the thermal effects of landscape parameters of urban parks in summer, micrometeorological and human thermal sensation data were analyzed and compared. Data were collected at three fixed locations and twenty-four transient locations in Hyowon Park, Suwon, Republic of Korea. The chosen locations were surfaced with different materials and were exposed to different direct solar radiation by trees or artificial shading devices. It was found that human thermal sensations were influenced most by the mean radiant temperature. The physiological equivalent temperature was two levels lower in thermal perception in shaded locations than sunny ones. Therefore, the most effective method of reducing the mean radiant temperature and human thermal sensations in summer is to create large shaded spaces by building artificial shading devices such as pergolas and planting trees with a high crown density. Among the surface materials, cement bricks, grass-flagstones, and coconut mats created better human thermal environments than baked bricks, polyurethane, and granite. Based on these results, we provide a list of improvements that can be used to guide future policy and design of urban parks to improve the thermal environment of urban outdoor spaces.