Plantation Conditions Research Articles

REDUCTION OF EFFECT OF GROWTH STRESS PRESENCE USING ENDLESS SCREW DURING KILN DRYING AND STEAMING AND HEATING TREATMENT IN LOG BEFORE SAWING

The relaxation of growth stress in trees growing in fast-growth conditions, as plantation in tropical areas, affects lumber quality during of sawing or drying process. It was evaluated two pretreatments (heating and steaming application) before sawing process and endless screw use to maintain the boards pressed during drying ofDipteryx panamensisand Hieronyma alchorneoideswood with objective to reduce the effects of relaxation of growth stress. Theresults showed endless screw is used to maintain the boards pressed, the moisture content (MC) or drying rate did not vary. The use of endless screws with daily adjustment during drying produced a reduction of cup, check and split defects in lumber and this treatment is accompanied with a pre-treatment before sawing (heating or steaming treatment) decreased theincidence of drying defects. Then the use of both treatments is an opportunity to reduce theeffects of relaxation of growth stress on the quality of the wood of D. panamensisand H.alchorneoidesfrom fast-growth plantation conditions.

Аналіз світових тенденцій у наукових розробках із захисту плодових насаджень від заморозків

The main trends in scientific research on the protection of fruit plantations from spring frosts were analyzed based on the study of patent documentation of the countries of the world. China and the USA have the largest shares of patented developments by countries that have issued protection documents. The number of scientific studies on the mentioned problem and the patenting of their results increased significantly in the late 20th and early 21st centuries, confirming its relevance for world fruit growing. But in the 20s of the 21st century, the number of patents issued in the USA, Canada, Japan, Ukraine, as well as WIPO and EPO decreased significantly, while those issued in China increased several times. Among all methods of protecting orchards from frost, only 15 % were patented after 2010. For devices (protective shelters/screens, their designs), 48 % of protection documents were issued after 2010. After 2010, 42 % of patents were issued on devices for protecting plantations from frost, of which only 8 % are mobile. Among all means of protecting fruit plantations from frost, only 8 % were patented after 2010. Researchers have proposed different approaches to protecting plants from frost due to the wide variety of the distribution of the value of the temperature decrease indicator and their duration in most regions where fruit crops are grown. In recent decades, the improvement of previously developed methods and means, devices and devices for protecting fruit crops from frost, and their combination in various variants to improve protection, has been carried out. Systems for controlling weather conditions in plantations and controlling frost protection devices, both remote and automatic, were also created.

АНАЛИЗ ЖИЗНЕСПОСОБНОСТИ ДРЕВЕСНЫХ ВИДОВ В ЗАЩИТНЫХ ЛЕСНЫХ ПОЛОСАХ АРИДНОЙ ТЕРРИТОРИИ ВОЛГОГРАДСКОЙ ОБЛАСТИ

To solve scientific and practical problems in the field of agroforestry of arid territories, it is particularly relevant to preserve protective forest plantations of artificial origin on agricultural lands, since they have a positive impact on the yield of agricultural crops. Increasing the resistance of tree plantations to unfavorable natural and climatic factors of the arid zone, increasing the period of the reclamation effect on soil fertility, improving the ecological state of agrarian landscapes is a priority task in agroforestry reclamation measures. Created in the middle of the XX century, without deep analysis of soil and geological conditions, without taking into account salt resistance and proper care for a long time, forest strips began to degrade and lost their basic functionality. Intended primarily to mitigate the harsh climate of the Volgograd region, forest strips have also lost their aesthetic appeal. Taking into account the considerable experience of artificial afforestation in the arid zone and in the conditions of the dry steppe, there is still no clear scientific justification for the creation of sustainable protective forest plantations that can provide an appropriate reclamation effect aimed at reducing wind speed, improving the microclimate of fields and stabilizing water and wind erosion. In order for agroforestry in the region to have the calculated effect, an analysis of tree plantations in protective forest strips was carried out, since it is necessary to improve the range of tree and shrub plantations that are used in the creation of artificial forest plantations. The heat resistance and winter hardiness of seeds of the most common tree plantations (such as Quercus robur, Ulmus pumila, гибриды вязов, Ulmus minor, Robinia pseudoacacia, Fraxinus lanceolata, Caragana arborescens, Ribes aureum, Tamarix ramosissima) were studied, their salt resistance and durability of the seed generation were studied. Based on the results obtained it was concluded that the most promising for protective afforestation are such genera as: Ulmus pumila, Ulmus pumila x carpinifolia, Ulmus carpinifolia, Robinia pseudoacacia, Celtis occidentalis и Caragana arborescens, the breeding efficiency of which has been proved by the general condition of many protective forest plantations and their resistance in the arid region.

Monitoring of the Condition of Green Plantations in Shevchenkivskyi District of Kharkiv (on The Example of Bittle Chestnut (Aesculus Hippocastanum L.)

In the complex of measures for improving atmospheric air quality in a modern city and reduction of noise pollution, special emphasis is placed on outdoor green spaces, which primarily perform a sanitary and hygienic function, protect residents and urban sites from harmful transport emissions, localization and partially absorb them. Purpose. Monitoring the state of green spaces in the Shevchenkivskyi district of Kharkiv (for example, bitter chestnut (Aesculus Hippocastanum L.) Methods. Analytical and synthetic method, geoinformation (cartographic modeling and processing of remote sensing data), analysis of information sources and methods of field research. Results. Based on the analysis of literature and fund materials and our own field research, information was obtained on the current state of plantings of common bitter chestnut in the Shevchenkivskyi district of Kharkov. A visual assessment of the quality of common bitter chestnut stands was made, in particular, damage to trees was determined. An inventory map of urban plantations of bitter chestnut in the usual Shevchenkivskyi region was developed using GIS technologies. Recommendations have been developed to improve the ecological state of common bitter chestnut plantations within the Shevchenkivskyi district of Kharkiv. Based on the results of this study and taking into account the preliminary work of scientists, it has been proved that the development of an inventory map of urban plantings of common bitter chestnut makes it possible to find out information about the state of the city's green spaces (number, types, age, diseases and damage, etc.). Conclusion. The obtained data on green spaces can determine the priorities for the development of landscape design, an action plan for urban green infrastructure to adapt to climate change. Based on reliable data, you can draw up a quality plan for the development of urban greening.

Deciphering Rhizosphere Microbiome Assembly of Castanea henryi in Plantation and Natural Forest.

Based on the importance and sensitivity of microbial communities to changes in the forest ecosystem, soil microorganisms can be used to indicate the health of the forest system. The metagenome sequencing was used to analyze the changes of microbial communities between natural and plantation Castanea henryi forests for understanding the effect of forest types on soil microbial communities. Our result showed the soil microbial diversity and richness were higher in the natural forests than in the plantation. Proteobacteria, Actinobacteria, and Acidobacteria are the dominant categories in the C. henryi rhizosphere, and Proteobacteria and Actinobacteria were significantly enriched in the natural forest while Acidobacteria was significantly enriched in the plantation. Meanwhile, the functional gene diversity and the abundance of functions in the natural forest were higher than that of the plantation. Furthermore, we found that the microbial network in the natural forests had more complex than in the plantation. We also emphasized the low-abundance taxa may play an important role in the network structure. These results clearly showed that microbial communities, in response to different forest types, provide valuable information to manipulate microbiomes to improve soil conditions of plantation.

Сurrent condition of pine plantations of Kyiv Polisya under the influence of environmental factors

The article describes the climate change in the study region for the period 1968-2020. It was specified that over the past fifty-nine years there has been an increase in average annual air temperature by 2,5°C, a decrease in relative humidity by 6,0% and average annual rainfall by 5 mm. According to the analysis, it was determined that during the period 2009-2020 significant damage to pine plantations of Kyiv Polissya is caused by the pests like common pine sawfly (Diprion pini L.), pine bark beetle (Aradus cinnamomeus Panz), pine silkworm (Dendrolimus pini L.), pine weevil (Leucaspis pusilla Loew), and pine star weaver (Acantholyda nemoralis Matsumura). Heterobasidion annosum (Fr.) Bref. has also caused a significant damage to pine forests over the past eleven years; the damaged area is of ​​12,8-15,9 thousand hectares.
 According to the hydrothermal analysis of the study area, it was determined that 2009 and 2015 were characterized as years of medium drought; 2010, 2016, 2017, 2020 were the years of low drought; 2011–2014, 2018, 2019 were the years of sufficient moisture supply. The analysis of the number W influence found that in the years of increased solar activity the number of phytopests increases, while in the years of minimal solar activity it decreases. Based on the statistical indicators, the analysis of CO2 emissions into the environment for the period 2009-2020 and it was found that since 2012 the amount of carbon dioxide emissions has decreased from 10,2 million tons to 3.7 million tons. Correlation analysis of all indicators showed the interaction between the area of ​​damaged trees by insect pests and the Wolf number, CO2 emissions into the environment, average annual precipitation amounts and hydrothermal moisture coefficient of Selyaninov G.T. There is also a correlation between the area of ​​damaged plantations by pine fungus and the average annual air temperature, relative humidity and CO2 emissions.

Growth and Productivity Modeling of Seven Eucalyptus Species in Souiniet’s Arboretum in the Northwestern of Tunisia

This study consists of the development of tree growth models to deduce stands productivity and determine the highest productive species in the conditions of the concerned plantation. Seven Eucalyptus, introduced in the arboretum of Souiniet (north-west of Tunisia, wet Mediterranean bioclimate) in a Cork Oak natural forest, were studied. Stem analysis and non-linear growth modeling regression equations were used to predict wood productivities. Gompertz and Chapman–Richards growth function appeared as being great numerical models to estimate the Eucalyptus tree diameter and height evolutions, respectively. Moreover, an adapted Chapman–Richards model allowed predicting the volume of trees in an efficient manner. The values of mean annual volume productivity of the Eucalyptus spp.studied, allow us to classify them in order of increasing annual productivity, as follows: E. sideroxylon, E. cinerea, E. maidenii, E. macrorhyncha, E. tereticornis, E. viminalis and E. bicostata. The first three Eucalyptus spp. appeared as the best-adapted and most suitable Eucalyptus trees for new plantations in this area. These species had the highest mean annual increments, ranged from 5 to 10 m3.ha−1.year−1 with 15 to 20 years of rotation. E. bicostata is the most promising, with annual average production exceeding 10 m3.ha−1.year−1 after 25 years, and reaching 20 m3.ha−1.year−1 at 40 years old. These modeling approaches provide additional knowledge on the productivity of the different Eucalyptus species, thus enabling forestry operators to simulate the development of forest stands in order to optimize timber production and harvesting.

Taxonomic composition and condition of tree plantations of roadside strips in Kyiv

Aim. The analysis of the taxonomic composition and living condition of tree plantations of roadside strips in Kyiv. Methods. Determination of the species composition and viability of trees and shrubs was carried out by route survey on test areas along the routes with different traffic intensity. The plants living condition was established according to the methodology developed by us, which provides an integrated vitality assessment based on a set of morphometric, reproductive and phenological features. Results. It is established that in the conditions of traffic flow of high intensity 23, of moderate 27 and of low 29 species of trees and bushes were found on the test areas. The tree plants of most common genera and species of roadside plantations are identified. The plants living condition analysis showed, that in the conditions of traffic flow of high intensity, plants of moderate and low vitality predominate; while in the conditions of moderate and low traffic intensity, the predominant numbers of plants have high vitality. Conclusions. Analysis of the range of roadside plantations indicates its limited and almost complete absence of conifers. The species composition is not optimal and is not always determined by the degree of resistance to transport pollution specific conditions. The woody plants vitality is largely determined by the traffic intensity and compliance with care technology.

Green infrastructure and relationship with urbanization – Importance and necessity of integrated governance

The article uses an interdisciplinary approach to study the links between urbanization and the state of the green infrastructure of the metropolis, which indicates the possibility of providing ecosystem services. This is important for the formation of a better management policy of green urban space for the sustainable development of the metropolis. In order to allow creation of forecast in time, spatial and statistical analysis of the relationship between the criteria of urbanization and ecosystem services were done, which resulted in spatial analysis – showing the distribution of the study area by condition and viability of green plantations depending on the level of urbanization to visualize their complex structure and condition. Indicators of urbanization were researched: 1) urbanization Index (UI); 2) Anthropogenic load index (Jal); 3) water erosion of the soil; 4) adventization index of grass cover (Inn); 5) nitrophils in grass tirer; and environmental indicators. Three most important groups of ecosystem services (ES) were identified quantitatively: 1) habitat quality, regulating ES – park area, mortality of trees, canopy density, stand condition index (Is), integral indicator of the impact significance (W), natural value index (Inv); 2) biodiversity conservation – Hstr, Biodiversity Indices; 3) provision of recreational ES – t, R. It was found that urbanization has a direct negative impact on ES, which contributes to the reduction of biodiversity, area, structure and condition of park ecosystems (PE). According to the proposed indices, the studied Kyiv park ecosystems form two large groups – 1) with a significant anthropogenic load and 2) with the best preservation of the forest environment, complex biotic structure. We made recommendations on the policy of management and preservation of green infrastructure in the context of rapid urbanization, especially on park ecosystems of the second group.

Assessment of forest crops created on the dependent lands of Rivne region

The article presents the amount of work on afforestation in the Rivne region over the past 5 years. The forestry and taxation indicators, the composition and condition of forest plantations created on the ancestral lands have been determined. A comparative assessment of the change in the stock of common pine crops depending on the age and types of forest growing conditions in height and the actual and potential stock at a fullness of 1.0 is carried out. According to the research results, the change in the average growth rate of pure Scots pine crops was determined under conditions A2 and B 2. The distribution of plantations in childbirth according to the degree of damage by root sponges and insect pests was carried out, the scale and harmfulness of these lesions were determined. Analysis of information on the stock of wood of pine crops indicates that more intensive growth is observed in 55-year-old plantations with some predominance in fresh subor conditions. The dependence of the phytosanitary state of plantations on the type of forest growing conditions and their composition was revealed. The most resistant are plantations that grow in conditions C 2 and D2. Healthy plantings, without signs of damage by pathogens and insect pests, occupy an area of 51.1 %. In the overwhelming majority, clean pine plantations were affected. The main reason for the decrease in their resistance is the root sponge. The extent of the spread of root rot is explained by the degree of degradation and low fertility of soils, which are transferred for afforestation, which is directly related to the nature of their use. Plantations characterized by a high degree of root sponge infestation account for 1.2 %. It was found that the proportion of healthy plantations increases by 15–18 % with the participation of deciduous species in the composition of the tree stand. The research results can be used to select the optimal options for the initial composition of plantations for various types of forest growing conditions. Key words: afforestation, forest plantations, fallows, self-seeded forests, agricultural lands, Scots pine, reserve lands.

Assessment of leaf damage degree in Aesculus hippocastanum L. during the growing season in the conditions of Dnipro city

One of the unique indicators of environmental pollution is Aesculus hippocastanum Linnaeus, 1753, distributed in different ecological conditions of most European cities in both the southern and northern temperate zones. For a long time bitter chestnut belonged to the number of highly resistant wood species. But in the last two decades, the condition of bitter chestnut plantations has deteriorated significantly due to the impact of adverse abiotic environmental factors (due to global climate change and increasing man-made load), and due to mass reproduction of phytophagous and phytopathogenic. A. hippocastanum especially suffers from chestnut miner (Cameraria ohridella Deschka & Dimič, 1986), for which it is the main forage plant. The aim of our study was to assess the degree of damage to the leaf surface of Aesculus hippocastanum L. during the growing season in the Dnipro. Analysis of damage to the leaf blades of the forage plant C. ohridella was performed for four years (2018–2021) visually on a modified scale proposed by M. D. Zerova et al. (2007). The research covered eight main park urban ecosystems of the Dnipro. Four stable generations of C. ohridella were established in the city of Dnipro. The development period of one separate generation of chestnut miner lasts from 65 to 110 days. The beginning of the flight of adults of the first generation occurs at the end of April and the beginning of May. Monitoring was carried out during three summer months, which corresponds to the main feeding period of the three most active generations of C. ohridella (I, II and III). A. hippocastanum leaf blades have been found to be damaged differently in different park urban ecosystems. The highest percentage of damage in all park areas is observed in August, when three generations were almost completely fed. A significant dependence of the area of affected leaves of bitter chestnut common invasive C. ohridella on the period of the growing season was found. According to our research, in all eight test plots, which corresponded to the main area and functional load of the green areas of the Dnipro, during the summer there is an increase in the area affected by the miner leaf in chestnuts. During the four years of observations (2018-2021), in the city of Dnipro, this generalized indicator ranged from 32% in June to 65% in August. This increase can be explained by the increase in the number of mines, due to the gradual emergence of the second and third generations of C. ohridella, each of which is more numerous than the previous one

Probing the potentiality of the defoliator Cricula trifenestrata Helfer silk: a revisit

BackgroundTransformation of pest to valuable product is considered to be a noteworthy innovation. This article explores the potentiality of wild silkworm Cricula trifenestrata Helfer for sustainable development towards human livelihoods.ResultsThe innate characteristics of this silkworm with robust rearing capacity have bestowed various aspects of biomaterials with special context to diversification of wild silk products. Views on challenges, prospects and the enigma of converting a pest to beneficial product are also unraveled. Exploration on utmost utilization of raw silk, scope for varied byproduct from silk waste may contribute a ray of hope for income generation to the rural population.ConclusionWith suitable plantation and congenial climatic conditions for rearing Cricula trifenestrata may serve as an alternative wild silk in contributing to the country’s wild raw silk production.

Cocoa plantation carbon stock at different years after planting (5,10,15) in Tomoni Beringin Jaya Village, East Luwu, South Sulawesi, Indonesia

This study aimed to determine cocoa carbon stocks based on the conditions of cocoa plantations in Tomoni Beringin Jaya Village, East Luwu, South Sulawesi, Indonesia. Carbon stocks were estimated from aboveground and belowground biomass using an allometric methodology. Sample sites were cocoa plantations; sampling intensity was 30% of the land planted with cocoa for 5 years (n = 214), 10 years (n=229) and 15 years (n=329), soil sampling disturb (measure soil organic carbon), un disturb (measure bulk soil bulk density) and soil bulk density at depth 0-10 cm and 10-20 cm. Carbon stock cocoa aboveground biomass at the age of 5 years (M45) was 1.89 ton C ha-1 and belowground biomass was 0.56 ton C ha-1 with proportion 77.19%:22.81%. Carbon stock cocoa aboveground biomass at the age of 10 year (BR25) was 3.66 ton C ha-1 and belowground biomass 1.01 ton C ha-1 with a proportion 78.37%:21.63%. Carbon stock cocoa aboveground biomass at 15 year (BR25) was 4.58 ton C ha-1 and belowground biomass of 1.21 ton C ha-1 with a proportion 79.07%:20.93%. Cocoa carbon stock at 5 year, 10 year, and 15 year respectively increased, nevertheless mean annual carbon stock cocoa decreased in 5 years cocoa aboveground biomass was 0.37 ton C ha-1 and belowground biomass 0.11 tonCa-1. Carbon stock cocoa 10 year aboveground biomass 0.36 ton C ha-1 and belowground biomass 0.10 ton C ha-1. Carbon stock cocoa 15 year aboveground biomass 0.30 ton C ha-1 and belowground biomass 0.08 ton C ha-1. Soil organic carbon showed dynamic under different year cocoa plantation. Soil organic carbon in cocoa plantation age 5 year was 0.031 tonCha-1, cocoa plantation age 10 year was 0.034 ton C ha-1, and cocoa plantation age 15 year was 0.043 ton C ha-1.

Використання технологій IoT для екологічного моніторингу міста

IoT technologies in the Big Data concept can radically change approaches in agricultural practices, but it is necessary to work out methods of processing and interpreting information that can be effective in crop practice. Since the dimensions of plants are too small for satellite imagery, the development of technologies can be done on trees whose dimensions are sufficient for their identification in satellite imagery. The purpose of the work is to identify and assess the condition of plantations, in particular trees, with the determination of their positioning on satellite images of megacities. Digital photographs created by optical and infrared lenses of the Obolonskyi district of Kyiv were used for the research. It was found that in the optical range for objects under direct sunlight, plant identification is possible, while shaded areas are identified with significant errors. When using the index for IR shooting IRtree = C1 - C2 + 100 it was possible to identify individual ranges that belong to the crown of trees and grass in direct sunlight and to some extent in the shade, which could not be achieved with the index for optical range GBtree = G - B + 100. Monochrome infrared and optical images were not suitable for plant identification, because when objects were in the shadow of buildings, the ranges of intensity of the color components of plants were superimposed on the ranges of foreign objects. For infrared and optical satellite images, spectral indices have been proposed that take into account several color components to assess the condition of plantations. For tree crowns under direct sunlight, approximately the same results were obtained for the proposed indices. However, the indices proposed for infrared photography are more selective, as they were able to identify separately the crowns of trees and plants on lawns, both in direct sunlight and in the shade of buildings.

Genetic diversity of Coffea canephora Pierre ex A. Froehner in Temanggung District, Indonesia based on molecular marker RAPD

Abstract. Authors. 2021. Genetic diversity of Coffea canephora Pierre ex A. Froehner in Temanggung District, Indonesia based on molecular marker RAPD. Biodiversitas 22: 4775-4783. Temanggung District in Central Java Province, Indonesia is one of robusta coffee production centers. The condition of coffee plantations in Temanggung shows variations in some morphological traits. Variations in coffee phenotypes are considered less profitable for farmers because they produce yields of undesirable quality in the global market. This study aimed to evaluate the genetic diversity of robusta coffee in Temanggung. The coffee plants were derived from six villages located at two levels of altitude. The morphological traits were observed from canopy width, trunk diameter, plant height, cherry volume, and bean volume, while the biochemical compositions were determined by caffeine content and brew’s pH value. The molecular assays were performed using PCR-RAPD with ten primers and species identification was based on the ITS rDNA. Our finding showed a variation in all morphological characters and biochemical compositions based on the LSD test 5%. The molecular marker RAPD revealed the genetic diversity by showing the DNA polymorphism levels of 95%, with the genetic similarity coefficient ranged from 0.35 to 0.86. The species identification also demonstrated that our robusta coffee was 97.11-99.70% similar to robusta coffee MK615737.1 from Philippines and robusta coffee DQ153593.1 from Cameroon. Thus, genetic diversity on six populations of robusta coffee was found, along with its variations on phenotypes which might lead the coffee yield quality to become uneven.

Condition and Stability of Plantations in the Zonal Ecotone of the Forest and Steppe of the Southern Urals

In the conditions of the zonal ecotone of the forest and steppe of the Southern Cis-Urals, the current state of forest ecosystems is characterized, the radial growth of Scots pine is considered as an indicator of the sustainability of plantations. Forest phytocenoses of the Southern Cis-Urals have class 2 and 3 of biological resistance, unfavorable in sanitary terms, which leads to the appearance of permanent foci of mass reproduction of insect pests of leaves and needles. These pests are actually indicators of the sustainability of the forest ecosystem. The plantations are especially strongly weakened in the zone of medium, strong and maximum anthropogenic impact on the environment. Differences in the radial growth of Scots pine are observed in the zonal ecotone of the forest and steppe. The dynamics of the radial growth of Scots pine in the Orenburg forestry indicates a decrease in the indicator over the years, which is interconnected with the dry climate of the steppe zone and partly the technogenic influence of industrial enterprises in Orenburg. The dynamics of the radial growth of Scots pine crops in the national park "Buzuluksky bor", on the contrary, increases over the years, which, in our opinion, is associated with more humid growing conditions in recent years. Comparing the average radial growth of Scots pine in the zonal ecotone of the forest and steppe, one can note higher rates in the forest zone of the national park "Buzuluksky bor" and lower rates in the steppe zone. The main method of collecting information on the state of forest cenoses was a field survey on temporary test areas, which were laid according to standard methods.

Decoding of forest belts using satellite images

The paper presents the results of decoding the current condition of protective forest plantations of the Volgograd region and their digital inventory mapping on the basis of remote sensing methods and GIS technologies. We have applied a three-level analysis of the system of forest belts located within an administrative district, a farmstead, and a single forest belt. The laboratory visual interpretation of space images has allowed us to analyze the horizontal projection of the forest belts canopy and crowns, their placement in the canopy, as well as pattern and structure. We have also deciphered the signs of the prevailing patterns of tree species mixing. As a result of the research, we have created digital cartographic models of forest belts, compiled digital standards of elm stands in a given age period, assesse taxation and reclamation features of the current state of plantations. The results obtained can be used to monitor the state of plantings and create a local agroforestry GIS.

Extracting Canopy Closure by the CHM-Based and SHP-Based Methods with a Hemispherical FOV from UAV-LiDAR Data in a Poplar Plantation

Canopy closure (CC), a useful biophysical parameter for forest structure, is an important indicator of forest resource and biodiversity. Light Detection and Ranging (LiDAR) data has been widely studied recently for forest ecosystems to obtain the three-dimensional (3D) structure of the forests. The components of the Unmanned Aerial Vehicle LiDAR (UAV-LiDAR) are similar to those of the airborne LiDAR, but with higher pulse density, which reveals more detailed vertical structures. Hemispherical photography (HP) had proven to be an effective method for estimating CC, but it was still time-consuming and limited in large forests. Thus, we used UAV-LiDAR data with a canopy-height-model-based (CHM-based) method and a synthetic-hemispherical-photography-based (SHP-based) method to extract CC from a pure poplar plantation in this study. The performance of the CC extraction methods based on an angular viewpoint was validated by the results of HP. The results showed that the CHM-based method had a high accuracy in a 45° zenith angle range with a 0.5 m pixel size and a larger radius (i.e., k = 2; R2 = 0.751, RMSE = 0.053), and the accuracy declined rapidly in zenith angles of 60° and 75° (R2 = 0.707, 0.490; RMSE = 0.053, 0.066). In addition, the CHM-based method showed an underestimate for leaf-off deciduous trees with low CC. The SHP-based method also had a high accuracy in a 45° zenith angle range, and its accuracy was stable in three zenith angle ranges (R2: 0.688, 0.674, 0.601 and RMSE = 0.059, 0.056, 0.058 for a 45°, 60° and 75° zenith angle range, respectively). There was a similar trend of CC change in HP and SHP results with the zenith angle range increase, but there was no significant change with the zenith angle range increase in the CHM-based method, which revealed that it was insensitive to the changes of angular CC compared to the SHP-based method. However, the accuracy of both methods showed differences in plantations with different ages, which had a slight underestimate for 8-year-old plantations and an overestimate for plantations with 17 and 20 years. Our research provided a reference for CC estimation from a point-based angular viewpoint and for monitoring the understory light conditions of plantations.

Assessment of the Condition of Pine Plantations in the Area of Influence of Municipal Waste Landfills on the Example of the Zhytomyr Landfill, Ukraine

Assessment of the Condition of Pine Plantations in the Area of Influence of Municipal Waste Landfills on the Example of the Zhytomyr Landfill, Ukraine

Microclimate and land surface temperature in a biodiversity enriched oil palm plantation

Agroforestry options such as mixed-species tree planting and natural regeneration in oil palm plantations may alleviate negative effects of forest loss on biodiversity and ecosystem functioning. The effects of agroforestry on microclimate and land surface temperatures (LST) remain largely unknown despite their central role in controlling abiotic and biotic factors and in buffering climate at a larger scale. We assessed spatial and temporal microclimate and LST variability in a biodiversity enrichment experiment, in which tree islands have been planted in an oil palm plantation in Sumatra (Indonesia). Four years after establishment of the experiment, we measured microclimate and LST using mini microclimate sensors and drone-recorded thermal images. We examined experimental effects of tree species richness (0, 1, 2, 3 or 6), plot size (25 m2, 100 m2, 400 m2, 1600 m2) and stand structural complexity on microclimate and LST. Diurnal patterns showed ambient air temperature peaks and relative humidity (RH) minima at 3 pm, whereas diurnal soil temperatures peaked around 6 pm. The lowest LST were observed from oil palm canopy leaves and the highest from bare soils and understorey vegetation (including trees). Spatial and temporal ranges of ambient air temperature were smaller than LST ranges, and average ambient air temperature and LST were positively correlated. Tree species diversity had no overall significant effect neither on microclimate nor LST, but humidity was higher in planted tree islands compared to natural regeneration only. Smaller plots were characterized by higher mean air, soil and LST, compared to larger plots. Structurally complex plots were associated with low mean and maximum values of ambient air temperature, soil temperature and LST and high mean and minimum RH. Still, conditions were hotter and drier in several experimental plots compared to conventional oil palm plantations, considering a higher transpiration in the latest. We conclude that stand structural complexity and tree island size control microclimate and LST in the experimental oil palm agroforests, but alleviating the harsh microclimate conditions in oil palm plantations might take longer to occur.