Tree Diameter Research Articles

Bryophyte community composition is influenced by microhabitat and cover of vascular plants and lichens in New Zealand montane forest

ABSTRACT Bryophytes are important to terrestrial ecosystems, as they build soil and improve habitats for vascular plants. We investigated the influence of substrate pH, light, and cover of lichens and vascular plants on bryophyte communities in different microhabitats near the Lewis Pass. The effect of tree diameter and trunk aspect on epiphytic communities was also examined. In total, 30 bryophyte species were identified in 98 0.25 m2 quadrats in five forest microhabitats (kānuka/mānuka and beech forest floor, beech tree trunks, and streamside and decomposing wood in beech forest). Bryophyte community composition in streamside microhabitats differed from all other microhabitats. Bryophyte community composition on the beech forest floor differed from the community on kānuka/mānuka forest floor; these differences were correlated with vascular plant and lichen cover. The composition and cover of epiphytic communities on tree trunks were correlated with aspect and lichen cover, there was no effect of tree diameter. No effect of substrate pH was found, although pH only ranged from 4 to 6. This study is one of the first in New Zealand to study the relationship between environmental factors and bryophyte communities in beech and kānuka/mānuka forests, contributing to our understanding of these understudied, key components of New Zealand forest ecosystems.

Current state of protective forest plantations with Sophora japonica (Sophora japonica L.) in the southern regions of Ukraine

The results of studies of the state, growth dynamics and agroforestry efficiency of shelterbelt forest plantations of different species composition in the southern regions of Ukraine are presented. The positive impact of shelterbelt forest plantations on the state of agricultural land is noted, which is manifested in the termination of water and wind erosion, accumulation of moisture in the soil, creation of a favourable microclimate in crops, increase in overall biodiversity, which leads to yield enhancement of field crops by 15 %. Their optimal species composition, parameters and optimal structure in the respective types of habitat conditions are determined. The current state and silvicultural and taxation indicators of shelterbelts were analyzed. A survey of plantations with Sophora japonica growing on the territory of Odesa and Mykolaiv regions was conducted. In these plantations, the heights and diameters of trees were measured, their condition was established, planting schemes were established for the creation of 2-4-6-row forest strips, and their current density at the age of 30 to 96 years was determined. Field-protective belts with Sophora japonica compared to Quercus robur, which are created on ordinary black soils, are well adapted to the arid climate. They have significantly higher productivity in all types of plantings and are endowed with a whole complex of high adaptive and economically valuable features, thanks to which they can be widely used in planting field-protective forest belts. It has been established that the current state of protective forest plantations is significantly negatively affected by anthropogenic factors: trees are damaged by unauthorized fellings, every year, a significant part of them is damaged by fire during the stubble burning, the plantations located near the settlement are used as a place for storing household and other waste, and uncontrolled grazing is carried out. To increase the effectiveness of protective forest plantations, we recommend bringing the plantations into proper sanitary condition through selective sanitary felling; to carry out reconstruction in the field protection plantations, as well as to organize monitoring of pest foci and control unauthorized fellings. Key words: forest shelter belt, reconstruction, main species, sanitary condition of a plantation, steppe zone, productivity.

The street tree distribution across a streetscape reflects the social inequality of Latin American cities

Due to the ecosystem services they provide, street trees are fundamental for the quality of life and well-being of the urban human population. However, street trees are usually not equitably distributed across streetscapes, making some demographic groups most vulnerable to the consequences of a poorly managed street tree community. In this study, we evaluated if the socioeconomic characteristics of a large Latin American metropolis (wealth and density of older adults and children) are related to aspects describing characteristics of the street tree community (number of trees, beta diversity, canopy diameter, and proportion of native trees). Our street trees database is comprised of more than 250,000 trees and 559 species. Through a model selection approach, we observed that all socioeconomic characteristics relate to an aspect of the street tree community. The number of trees increased with wealth, but the highest densities of older adults were observed in regions with fewer trees. Canopy cover, conversely, decreased in wealthier neighborhoods and in regions with a higher density of children, while increasing with the density of older adults. Beta diversity of native trees also decreased with wealth. These results not only highlight the luxury effect across the streetscape but reflect the social inequality of Latin American cities: most people from both demographic groups live in regions with a less exuberant tree cover. Our approach can help identify the strengths and weaknesses regarding the plan and management of this street tree community, assisting in the definition of public policies and guidelines for a more sustainable and equitable urban landscape.

Prediction Models for Ceiba pentandra in the Guinea Savanah Ecological Zone of Ghana

This study investigated the relationships between seven dendrometry variables in Ceiba pentandra. The relationships between stem diameter at breast height, total tree height, crown diameter, crown height, crown ratio, crown projection area and number of branches. Also, the relationship between Crown diameter and total tree height was studied. Regression prediction models were derived using simple linear regression analysis. Pearson correlation between variables was done using the Pearson’s Correlation coefficient. Stem diameter at breast height and crown diameter were used as independent variables as they are readily easy to measure with high accuracy. The study showed that positive correlations exited between stem diameter at breast height and total tree height, crown diameter, crown height, crown projection area, number of branches and crown ratio. Again, a positive correlation exited between the crown diameter and total height (0.39). The value of Pearson correlation coefficient (r) between the stem diameter at breast height, total tree height, crown diameter and crown height was 0.98; that between stem diameter at breast height and crown projection area was 0.95; between stem diameter at breast height, number of branches and crown ratio was 0.96. The correlation coefficient between crown diameter and total height was also 0.98. The coefficient of determination (Ar2) between the stem diameter at breast height, total tree height and crown height was 0.9; between stem diameter at breast height and crown diameter was 0.91; between stem diameter at beast height and crown projection area was 0.84; and 0.88 between stem diameter at breast height, number of branches and crown ratio. The coefficient of determination between crown diameter and total tree height was 0.9. Thus, the stem diameter at breast height accounted for about 90% of the total tree and crown heights. Also stem diameter accounted for 91% of crown diameter, 84% of crown projection area, and 88% of both crown ratio and number of branches. The crown diameter, on the other hand, accounted for 90% of the crown projection area. P-values were significant at 0.05 for all the variables studied (P ≤ 0.05). The models developed will enhance decision making in forest management and save cost and time spent in collecting data on these dendrometry variables studied.

Blue Carbon in Mangroves of the Arid Zones of San Ignacio and El Dátil Lagoons, El Vizcaino Biosphere Reserve, Baja California, Mexico

Estimation of carbon (C) stocks revealed a very high carbon sequestration potential of mangroves, which play a major role in the global C cycle. The C stored in the biomass of live trees can be estimated from above- and below-ground measurements, i.e., tree diameter and height, leaf litter, root biomass, necromass, and soil. The allocation of biomass and C in the scrub mangrove forest is influenced by various factors, including low structural development. The objective of this study was to estimate the carbon stock (in relation to biomass) and storage in the soil of the San Ignacio and El Dátil lagoons in an arid region of the north Pacific. Above-ground biomass (AGB) was estimated based on mangrove structure and leaf litter; below-ground biomass (BGB) was measured by extracting root cores (45 cm depth) and soil (1.2 m depth). Biomass values were converted to carbon with allometric equations. We found an inverse relationship between BGB content (roots) and above-ground structural development, with a mean total biomass (AGB + BGB) of 101.7 MgC ha−1. Below-ground carbon content (roots, necromass, and soil) was 2.8 times higher than above-ground carbon content (trees and litter). Control sites (devoid of vegetation) adjacent to the mangrove have recorded low carbon stocks of 7.3 MgC ha−1, which supports the recommendations for conserving and restoring degraded areas. The present study contributes valuable information on carbon related to mangrove biomass and stored in the soil of arid mangrove areas of northwestern Mexico.

Biomass, carbon stock and sequestration in various conditions of mangrove forests in Sungai Apit, Siak, Riau, Indonesia

Abstract. Fatonah S, Hamidy R, Mulyadi A, Efriyeldi. 2023. Biomass, carbon stock and sequestration in various conditions of mangrove forests in Sungai Apit, Siak, Riau, Indonesia. Biodiversitas 24: 5837-5846. The value of aboveground carbon is influenced by differences in conditions of the mangrove. Therefore, this study aimed to estimate biomass, as well as carbon stock and sequestration in various mangrove forests within Sungai Apit Siak, including natural, rehabilitated, and degraded forests. The Line Transect Plot method was used for sampling. Aboveground biomass was determined using an allometric equation based on mangrove stem diameter. Stem diameter measurements were taken from mangrove vegetation in three forest conditions across three villages in Sungai Apit, Siak. The findings revealed that natural forests contained higher values of biomass, carbon stock, and sequestration at 256, 128, and 470 tons/ha, respectively, compared to rehabilitated and degraded forests. The variability in these parameters across different mangrove forests was influenced by stands characteristics, specifically basal area and mean tree diameter, which were associated with the age of mangrove vegetation and recovery duration. Notably, Rhizophora mucronata, Sonneratia caseolaris, and Avicennia alba exhibited the highest carbon sequestration. These results highlighted that Sungai Apit mangrove forests store a relatively high carbon stock, emphasizing the importance of implementing proper conservation and management measures to ensure sustainability.

Seasonal roost characteristics and fall behavior of coastal populations of Northern Myotis (Myotis septentrionalis)

Abstract Temperate bats exhibit seasonal and sex differences in resource selection and activity patterns that are influenced by ambient conditions. During fall, individuals face energetic trade-offs as they make choices relating to migration, mating, and hibernation that may diverge for populations throughout their range. However, research has largely focused on the summer maternity and winter hibernation seasons, whereas the prehibernation period remains comparatively understudied. Northern Myotis (Myotis septentrionalis) have experienced precipitous population declines from white-nose syndrome (WNS), leading to their protected status in the United States and Canada. Therefore, understanding their ecology throughout the year is paramount to inform conservation. We compared seasonal roosts and documented fall behaviors between study sites and sexes on 3 islands: Long Island (New York), Martha’s Vineyard, and Nantucket Island (Massachusetts). Between 2017 and 2020, we radio-tracked 54 individuals to analyze activity patterns and characterize fall roosts to compare with previously known summer roosts. Summer tree roosts were of smaller diameter, later stages of decay, and lower canopy closure than those used in fall. Both sexes selected trees of similar diameter and decay stage during fall. Anthropogenic roost use was documented in both seasons but use of anthropogenic structures was greater during fall and increased as the season progressed. Bats made short inter-roost movements with males traveling greater distances than females on average. Activity occurred until late November, with males exhibiting a longer active period than females. We tracked 23% of tagged bats to local hibernacula in subterranean anthropogenic structures, the majority of which were crawlspaces underneath houses. Use of anthropogenic structures for roosts and hibernacula may facilitate survival of this species in coastal regions despite the presence of WNS infections. Timing of restrictions on forest management activities for bat conservation may be mismatched based on prehibernation activity observed in these coastal populations, and the conservation of habitat surrounding anthropogenic roosts or hibernacula may be warranted if the structures themselves cannot be protected.

Contributions to the knowledge of Turkish saproxylic beetle fauna of Anatolian sweetgum forests

The aim of this study was to determine the saproxylic beetle species (Coleoptera) present in Anatolian sweetgum, Liquidambar orientalis Miller (Saxifragales: Altingiaceae) forests, to reveal the contribution of this endemic tree species to insect biodiversity. Beetles were sampled in two areas in Muğla province of Türkiye, where L. orientalis is the most widely distributed tree species. Five old trees (diameter at breast height 36.0-51.9 cm) were selected in each area and two trap types were used on each tree. Traps were set on March 13, 2021, and checked once a month for six months. At the end of the study, 1,302 individuals belonging to 108 species from 33 families were obtained. Fifteen beetle species were new records for the fauna of Türkiye. The families with most individuals were Curculionidae (555), Anobiidae (325) and Tenebrionidae (104). Families with the highest number of represented species were Anobiidae (15), Elateridae (13), Curculionidae (8) and Tenebrionidae (8). According to the IUCN Mediterranean Red List, Ectamenogonus montandoni (Buysson, 1889) (Coleoptera: Elateridae) is classified as endangered (EN) and Propomacrus bimucronatus (Pallas, 1781) (Coleoptera: Euchiridae) as vulnerable (VU).

Determining Allometry and Carbon Sequestration Potential of Breadfruit (Artocarpus altilis) as a Climate-Smart Staple in Hawai‘i

Breadfruit (Artocarpus altilis) is an underutilized Pacific tree crop that has been highlighted as having substantial potential to contribute to global food security and climate-smart agriculture, including adaptation to and mitigation of climate change. To explore the carbon sequestration potential of breadfruit production, we characterize tree volume, wood density, carbon density, foliar biomass, and growth rates of breadfruit in Hawai‘i. Strong relationships to trunk or branch diameter were displayed for wood density (r2 0.81), carbon density (r2 0.87), and foliar biomass (r2 0.91), which were combined to generate an allometric prediction of tree volume (r2 0.98) based on tree diameter at breast height. Growth rates, as measured by diameter at breast height, were well predicted over time when trees were classified by habitat suitability. We extrapolate potential breadfruit growth and carbon sequestration in above-ground biomass to the landscape scale over time. This study shows that breadfruit is on the low end of broadleaf tropical trees in moist and wet environments, but in an orchard can be expected to sequester ~69.1 tons of carbon per hectare in its above-ground biomass over a 20-year period.

Plant functional traits and tree size inequality improved individual tree height prediction of mid-montane humid evergreen broad-leaved forests in southwest China

Tree height and diameter at breast height (DBH) are key survey factors in forest inventory. Compared to measuring DBH, the process of measuring tree height is time-consuming, labor-intensive and costly, especially in natural mixed forests. Tree height is therefore commonly predicted using height-diameter (H-D) models. Nevertheless, developing H-D models for natural mixed forests are hampered by the large diversity of tree species and the small number of rare tree species observed. In this study, a nonlinear mixed effects H-D model was established for a mid-montane humid evergreen broad-leaved forest in southwest China. For this purpose, we classified tree species by K-means clustering according to the specific plant functional traits. Data were collected from 5, 737 trees in 100 subplots with 86 species. The results revealed that the nonlinear mixed effects model of tree height accounted for 75% of the variation in tree height without significant heteroscedasticity, and that the model parameters had biological significance. In the 10-fold cross validation, no clear fluctuation in the model evaluation metrics was observed, indicating the absence of overfitting in the model. Of the 15 stand variables, dominant height (Hd) and Margalef’s index of DBH (DMg), which contributed the most to the height-diameter model, were selected to expand the model. Our findings suggest that tree height increased with increasing values of Hd and DMg, and vice versa. This study highlights the feasibility of categorizing natural mixed forests by utilizing plant functional traits and the influential role of tree size inequality on tree height variation.

Ancient, veteran and other listed trees as nest sites for wild-living honey bee, Apis mellifera, colonies

Wild-living honey bee (Apis mellifera) colonies naturally nest in old cavity-bearing trees throughout their range, but this important nesting habitat is in global decline. Here we determine the use of ancient, veteran and other listed trees as nest sites by wild-living honey bee colonies in Britain and investigate the effect of tree size, genus and management on occupancy. Over 1,000 trees of special interest (TSIs) were surveyed in southeast England using the Ancient Tree Inventory (ATI) of the Woodland Trust, a charity that protects and promotes trees in Britain. 2% of all TSIs and 4.4% of TSIs with cavities were occupied by wild-living honey bee colonies (n = 21). Occupancy positively correlated with tree diameter, which is surprising given that the overall sample already had a large mean diameter of 1.3 m. Wild-living colonies occupied sweet chestnut (Castanea sativa) more frequently than expected (7% versus 2% overall), probably due to their large mean diameter (1.6 m) and proportion of trees with cavities (73%). Heights of occupied tree cavities (including non-ATI trees) ranged from 0 to 18.2 m with a median of 6.8 m, entrance size ranged from 2.2 to 322 cm2 with a median of 33.8 cm2 and entrance orientation was not significantly different from random.

Tradeoffs between timber and wildlife habitat quality increase with density in longleaf pine (Pinus palustris) plantations

Longleaf pine (Pinus palustris), a historically abundant tree species in the southeastern United States, is often planted to restore the ecologically and culturally important longleaf pine ecosystem that once covered vast acreages in the southeastern United States. Government cost-share programs that support establishment of these plantations place restrictions on planting rates to promote wildlife habitat, as greater tree planting density may reduce canopy openness and herbaceous plant cover that are critical components of habitat for priority species, including gopher tortoise (Gopherus polyphemus) and Bachman’s sparrow (Peucaea aestivalis). However, there is expressed concern among some forest managers that more open grown trees in the plantations will be of inferior timber quality with more and larger horizontal branches and associated knots. We examined how density affects dynamics and tradeoffs among understory vegetation structure and composition, longleaf pine stem form (branch density and straightness), and longleaf pine survival by sampling 73 plantations of various ages (5–25 years) and planting rates (653–2445 trees per hectare (TPH)/264–990 trees per acre (TPA)) throughout the southeastern United States. We documented a relationship between planting rate and longleaf pine stand density at time of sampling (r = 0.69, p = 0.0001) and relationships between stand density and habitat and timber quality metrics. Greater stand density resulted in lower tree diameters but greater stand basal area than lower stand density. Higher planting rates led to lower branch density and lower straightness grades than lower planting rates. Canopy openness decreased with greater stand density, and bare ground cover and herbaceous cover decreased as density and stand age at time of sampling increased. Based on our results, we suggest that lower maximum planting rates are appropriate when wildlife habitat is a program objective because lower rates result in fewer tradeoffs, as reducing planting rates slows degradation of wildlife habitat when compared with higher maximum planting rates that have only mixed benefits on timber quality.

Prescribed fire lessens bark beetle impacts despite varied effects on fuels 13 years after mastication and fire in a Sierra Nevada mixed-conifer forest

Mastication, thinning, and prescribed fire can help shift fire-prone forests to a structure and composition more resilient to wildfire, but the ability to evaluate treatment effectiveness requires monitoring forest response to disturbances over time after treatment. In this study, we investigated fuel loadings, forest structure, and tree growth to assess treatment legacies thirteen years after mastication, prescribed fire, and surface fuel pull-back from tree boles in Sierra Nevada mixed-conifer forest. An outbreak of bark beetles between 2011 and 2018 impacted all plots but burned treatments had lower overstory mortality relative to unburned treatments which experienced an 80 % decline in live tree biomass. Tree diameter, canopy density, and surface fuel loadings became similar across all treatments during the 13 year time period. Height to live crown remained elevated in burned treatments relative to the control but had lowered by an average of 1.9 ± 0.3 (SE) m across all treatments. Radial tree growth did not have a sustained response to treatment and was greater in burned treatments for only a single year, 2011, several years post-treatment. Prescribed fire decreased duff mass by 56 % relative to unburned treatments but did not affect forest floor bulk density. Downed woody fuel loadings (1-h – 1000-h) were similar across treatments. The invasive Bromus tectorum (cheatgrass) had uniformly high cover across treatments. Whereas treatments were largely ineffective at producing long-term reductions in surface fuel loadings, the enduring reductions in duff loadings and reduced overstory mortality support the long-term utility of prescribed fire. Cumulatively, our results highlight the potential for prescribed fire to reduce overstory mortality and duff loadings in dry mixed-conifer forests, thereby contributing more effectively to fire-resilient characteristics relative to other fuel reduction treatments.

Foraging Niche Differentiation of Five Woodpecker Species in the Primitive Broadleaved Korean Pine Forests of Northeast China

Explaining the mechanism of the coexistence of sympatric species is an important goal of ecology. Five species of woodpeckers coexist in the broadleaved Korean pine forest of Liangshui National Nature Reserve, including the Black Woodpecker (Dryocopus martius), Great Spotted Woodpecker (Dendrocopos major), Lesser Spotted Woodpecker (Dendrocopos minor), Three-toed Woodpecker (Picoides tridactylus), and White-backed Woodpecker (Dendrocopos leucotos). Woodpeckers are considered to be keystone species because of their role as ecosystem engineers, creating breeding and shelter sites for many vertebrate and invertebrate taxa. As woodpeckers are predominant in primary forests, they are sensitive to changes in forest ecosystems. To understand their coexistence mechanisms and propose conservation strategies, it is necessary to investigate their foraging niche differentiation. This study aimed to identify the foraging behavior parameters and foraging tree parameters of five woodpecker species in Liangshui Reserve from October to December. The foraging niches of five woodpecker species were observed, including the type of foraging techniques, foraging height, foraging site, foraging duration, tree species being foraged upon, diameter of the foraging tree at breast height, foraging tree height, and decay status of trees. Our results identified that there were significant differences in the overall foraging ecology of the five species of woodpecker at Liangshui Reserve. The Great Spotted Woodpecker and Lesser Spotted Woodpecker had more diverse foraging patterns and preferred to forage on live trees. The Black Woodpecker and Three-toed Woodpecker excavated and pecked at the trunks of decaying spruce and fir trees. The White-backed Woodpecker preferred to forage in broadleaved trees. The choice of foraging sites was complicated. The size of the foraging trees and decay status of trees were important bases for woodpeckers when choosing trees to forage from. Different woodpeckers achieve stable coexistence through the separation of their foraging niches. This information regarding foraging behavior and foraging tree characteristics provides a basis to study the coexistence patterns of woodpeckers. Our research into woodpecker foraging should be used to inform forest management practices, protect forest ecosystem diversities, and maintain woodpecker community diversity.

Monitoring and Investigating the Change Patterns of Major Growth Parameters of Almond (Badam) Trees under Different Irrigation Conditions

Knowledge of the response of growth parameters of almond (Badam) trees to different water supply conditions is important for Badam production. To identify growth parameters that are sensitive to water deficit in almond trees, field experiments were conducted during a median water year to monitor the major growth characteristics of almond trees under different irrigation conditions in Shache County, Xinjiang, China. A field (in-situ) monitoring system was also constructed using various sensors for the continuous and non-destructive monitoring of the growth parameters, such as soil water in the root zone, canopy temperature depression, trunk diameter, and fruit diameter of almond trees. The results confirmed the reliability of the monitoring system. Both canopy temperature depression and the diameter shrinkage of the trunk and fruit were significantly negatively correlated (r values ranging from −0.996 to −0.823) with the irrigation water quantity. This correlation was observed from the young fruit stage to the maturation stage of almond trees, under irrigation conditions representing 50–100% of crop evapotranspiration (ETc). These parameters were sensitive (|r| ≥ 0.778) to the water deficit status of almond trees from 14:00 to 18:00 in sunny weather. These results can provide both technical and theoretical support for real-time non-destructive assessment of the water deficit status of almond trees.

Assessment of the Full Density Curve in Stand Density Management Diagrams for Hinoki (Chamaecyparis obtusa) in Kyushu Island, Japan: Implications for Forest Management

Accurate forest information on tree species, stand age, tree density, and stand volume is required to ensure effective forest management practices. In Japan, forest information is consolidated in forest yield tables and stand density management diagrams (SDMDs) that are specifically designed for major forest plantation species. In this study, we analyzed whether the current full density curve in the SDMD of Hinoki (Chamaecyparis obtusa) plantation stands in Kyushu Island aligns with the characteristics of the existing stands. Data from 18 Hinoki forests were used to measure tree heights, diameters, and densities. Equations were developed to establish relationships between stand factors, and various curves were derived for average height, competition ratio, full density, yield ratio, average diameter, and natural mortality. The results showed that the current full density curve in the SDMD for Hinoki plantation stands did not completely align with the characteristics of the existing Hinoki plantation stands in Kyushu Island. Thus, the full density curve in the SDMD for the Hinoki stands in this region should be significantly adjusted. These results can enhance forest management in Japan and advance SDMD modeling and its application in forest planning and management.

Biomass accumulation in trees and downed wood in northern hardwood forests: Repeated measures of a successional chronosequence in New Hampshire, USA

Successional, second-growth forests dominate much of eastern North America; thus, patterns of biomass accumulation in standing trees and downed wood are of great interest for forest management and carbon accounting. The timing and magnitude of biomass accumulation in later stages of forest development are not fully understood. We applied a “chronosequence with resampling” approach to characterize live and dead biomass accumulation in 16 northern hardwood stands in the White Mountains of New Hampshire. Live aboveground biomass increased rapidly and leveled off at about 350 Mg/ha by 145 years. Downed wood biomass fluctuated between 10 and 35 Mg/ha depending on disturbances. The species composition of downed wood varied predictably with overstory succession, and total mass of downed wood increased with stand age and the concomitant production of larger material. Fine woody debris peaked at 30–50 years during the self-thinning of early successional species, notably pin cherry. Our data support a model of northern hardwood forest development wherein live tree biomass accumulates asymptotically and begins to level off at ∼140–150 years. Still, 145-year-old second-growth stands differed from old-growth forests in their live ( p = 0.09) and downed tree diameter distributions ( p = 0.06). These patterns of forest biomass accumulation would be difficult to detect without a time series of repeated measurements of stands of different ages.

Soil Carbon Stock and Indices in Sandy Soil Affected by Eucalyptus Harvest Residue Management in the South of Brazil

There has been limited research on the effect of eucalyptus harvest residue management on soil organic carbon (SOC) in subtropical environments. This research evaluated the effect on soil C indices of the following eucalyptus harvest residue managements: AR, with all forest remnants left on the soil; NB, where bark was removed; NBr, in which branches were removed; NR, which removed all residues; and NRs, which is same as NR but also used a shade net to prevent the litter from the new plantation from reaching the soil surface. C stocks within the soil depths of 0–20 cm and 0–100 cm increased linearly with the C input from eucalyptus harvest residues. In the layer of 0–20 cm, the lowest soil C retention rate was 0.23 Mg ha−1 year−1, in the NR treatment, while in the AR treatment, the retention rate was 0.68 Mg ha−1 year−1. In the 0–100 cm layer, the highest C retention rate was obtained in the AR (1.47 Mg ha−1 year−1). The residues showed a high humification coefficient (k1 = 0.23) and a high soil organic matter decomposition rate (k2 = 0.10). The carbon management index showed a close relationship with the C input and tree diameter at breast height.

Genetic Variability and Divergence Studies in Quantitative Traits of Wild Pomegranate (Punica granatum L)

The mean performance and variability in quantitative traits of Punica granatum seed sources collected from five different districts comprising of ten seed sources. Two seed sources were considered from each district viz; Narag and Neripul from Sirmour district, Waknaghat and Sadhupul from Solan district, Sundernagar and Rewalsar from Mandi district, Mohal and Banjar from Kullu district, Basantpur and Sunni from Shimla district of Himachal Pradesh, India, were evaluated during the year 2018-19. The quantitative traits viz., morphological and seedling characteristics of seed sources varied significantly among the different districts and within the districts. The phenotypic coefficient of variation (PCV) for all the characters was slightly higher than genotypic coefficient of variation (GCV), which signified the presence of environmental influence to some degree in the phenotypic expression of characters. Collar diameter had the highest PCV (76.83) and GCV (26.67). Genetic advance was recorded as maximum for tree diameter per plant (5.57), whereas genetic advance as percent of mean was highest for tree height (4.86). Highest heritability (H2 , 99.77) was coupled with higher genetic advance (5.57) estimated for tree diameter per plant, which indicated that the character is controlled by additive genes and therefore further improvement could brought by selection. Tree diameter was significantly and positively associated with most of the characters except number of branches per plant, at both genotypic and phenotypic levels; therefore, these are important prerequisites to formulate a successful improvement program. Cluster analysis was performed and the seed sources were grouped into three clusters. The results showed significant variance among different morphological characters, traits namely tree height (m), tree diameter (cm), crown spread E-W (m), crown spread N-S (m), fruit weight (g), leaf length(cm), internodal length(cm), collar diameter (mm), number of branches per plant and leaf petiole (cm)

TERRESTRIAL 3D MAPPING OF FORESTS: GEOREFERENCING CHALLENGES AND SENSORS COMPARISONS

Abstract. Terrestrial 3D reconstruction is a research topic that has recently received significant attention in the forestry sector. This practice enables the acquisition of high-quality 3D data, which can be used not only to derive physical forest criteria such as tree positions and diameters, but also more detailed analyses related to ecological parameters such as habitat availability and biomass. However, several challenges must be addressed before fully integrating this technology into forestry practices. The primary challenge is accurately georeferencing surveyed 3D data acquired in the same location and placing them into a national projection reference system. Unfortunately, due to the forest canopy, the GNSS signal is often obstructed, and it cannot guarantee sub-meter accuracy. In this paper, we have implemented an indirect georeferencing methodology based on spheres with known coordinates placed at the forest’s edge where GNSS reception was more reliable and accurate than under the canopy. We evaluated its performance through three analyses that confirmed the validity of our approach. Indeed, the accuracy of the TLS point cloud, georeferenced using our method, is within a centimetre level (4.7 cm), whereas mobile scanning methods demonstrate accuracy within the decimetre range but still less than a metre. Additionally, we have initiated the analysis of a potential future application for mixed reality headsets, which could enable real-time acquisition and visualisation of 3D data.