Crown Condition Research Articles

Forest health study in efforts to preserve community forest agroforestry patterns in Kubu Batu Village, Gedong Tataan District, Pesawaran Regency, Lampung Province

The agroforestry pattern community forest in Kubu Batu Village, Gedong Tataan District, Pesawaran Regency, Lampung Province has essential values for the community, both economically, ecologically, and socially. Therefore, to ensure the sustainability of the community forest, a forest health assessment is carried out. Forest health assessment is one of the criteria for achieving community forest sustainability. This study aims to determine the condition (status) and ecological factors that affect the health level of community forests using agroforestry patterns in Kubu Batu Village, Gedong Tataan District, Pesawaran Regency, Lampung Province. The research methods used are the Forest Health Monitoring method to measure forest health with the Forest Health Assessment Information System (SIPUT) and sperm rank correlation to determine the relationship between ecological factors and the health level community forests using agroforestry patterns. The results showed the condition (status) of community forest health in agroforestry patterns with good categories in cluster plots 2, 4, 5, and 6, moderate categories in cluster plots 1 and 7, and bad categories in cluster plots 3. Strongly positive/unidirectional agroforestry patterns are the crown condition and tree species diversity. This condition illustrates that it preserves community forests using agroforestry patterns in Kubu Batu Village is necessary to focus tree species diversity attention on tree crown parameters. Thus, the health status of community forest agroforestry patterns in Kubu Batu Village is good. This proves that the people there have made efforts to maintain the sustainability of their community forests.

Defoliation, Recovery and Increasing Mortality in Italian Forests: Levels, Patterns and Possible Consequences for Forest Multifunctionality

Forest health and multifunctionality are threatened by global challenges such as climate change. Forest health is currently assessed within the pan-European ICP Forests (International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests) programme through the evaluation of tree crown conditions (defoliation). This paper analyses the results of a 24-year assessment carried out in Italy on 253 permanent plots distributed across the whole forested area. The results evidenced a substantial stability of crown conditions at the national level, according to the usual defoliation thresholds Defoliation > 25% and Defoliation > 60%, albeit with species-specific patterns. Within this apparent temporal stability, an increased fraction of extremely defoliated and dead trees was observed. Extreme defoliation mostly occurred in years with severe summer drought, whereas mortality was higher in the years after the drought. The results for singular species evidenced critical conditions for Castanea sativa Mill. and Pinus species, whereas Quercus species showed a progressive decrease in defoliation. Deciduous species, such as Fagus sylvatica L., Ostrya carpinifolia Scop. and Quercus pubescens Willd. suffer the loss of leaves in dry years as a strategy to limit water loss by transpiration but recover their crown in the following years. The recurrence of extreme heat waves and drought from the beginning of the XXI century may increase the vulnerability of forests, and increased tree mortality can be expected in the future.

Early detection of spruce vitality loss with hyperspectral data: Results of an experimental study in Bavaria, Germany

Vitality loss of trees caused by extreme weather conditions, drought stress or insect infestations, are expected to increase with ongoing climate change. The detection of vitality loss at an early stage is thus of vital importance for forestry and forest management to minimize ecological and economical damage. Remote sensing instruments are able to detect changes over large areas down to the level of individual trees. The scope of our study is to investigate whether it is possible to detect stress-related spectral changes at an early stage using hyperspectral sensors. For this purpose, two Norway spruce (Picea abies) forest stands, both different in age and maintenance, were monitored in the field over two vegetation periods. In parallel, time series of airborne hyperspectral remote sensing data were acquired. For each stand 70 trees were artificially stressed (ring-barked) and 70 trees were used as control trees. The data collected in south-eastern Germany consists of measurements at multiple times and at different scales: (1) crown conditions were visually assessed in the field (2) needle reflectance spectra were acquired in the laboratory using a FieldSpec spectrometer, and (3) hyperspectral airborne data (HySpex) were flown at 0.5 m spatial resolution. We aimed for a simultaneous data acquisition at the three levels. This unique data set was investigated whether any feature can be discriminated to detect vitality loss in trees at an early stage. Several spectral transformations were applied to the needle and tree crown spectra, such as spectral derivatives, vegetation indices and angle indices. All features were examined for their separability (ring-barked vs. control trees) with the Random Forest (RF) classification algorithm. As result, the younger, well maintained forest stand only showed minor changes over the 2-year period, whereas changes in the older forest stand were observable both in the needle and in the hyperspectral tree crown spectra, respectively. These changes could even be detected before changes were visible by field observations. The tree spectral reactions to ring-barking were first noticeable 11 months after ring-barking and 6 weeks before they were visible by field inspection. The most discriminative features for separating the two groups were the reflectance spectra and the spectral derivatives, over the VIs or angle indices. The tree crown spectra of the two groups could be separated by the RF classifier with a 79% overall accuracy at the beginning of the second vegetation period and 1 month later with 92% overall accuracy with high kappa index. The results clearly demonstrate the great potential of hyperspectral remote sensing in detecting early vitality changes of stressed trees.

INFLUENCE OF A PREFABRICATED-CROWN ROLLING PROCESS ON THE CORROSION BEHAVIOUR OF AZ31 MAGNESIUM ALLOY

The present study aims to investigate the effect of a prefabricated-crown rolling process on the corrosion characteristic of the AZ31 magnesium alloy. Specimens made of the AZ31 alloy were rolled under various crown conditions, and their microstructure evolution and corrosion behavior were analyzed. The corrosion behavior was studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the corrosion-current density of the AZ31 alloy with a side pressure of 37.5 % of the plate thickness of the precast convexity decreased from 3.79 × 10–6 A/cm2 to 1.80 × 10–6 A/cm2, and the difference between the edge and the middle of the AZ31 alloy was shortened from 2.05 × 10–6 A/cm2 to 1.14 × 10–6 A/cm2. The charge-transfer resistance also increased from 507.1 Ω·cm2 to 581.2 Ω·cm2. The improvement in the corrosion resistance is a result of the more stable corrosion products and microstructure refinement formed after the prefabricated-crown rolling process.

The use of measurable traits of trunk and crown to assess the biosocial classes of oak trees (Quercus robur L.)

The crown class assessment is a key element in forestry practice. It is a traditional method that finds application in thinning plans, assessment of site index, tree competition, or crown condition. Assigning trees into a given class is done during field surveys and requires precision and experience to avoid inaccuracy. Therefore, Kraft’s system has often been criticized and modified. Thus, in our study, we aimed to analyse whether the directly measured traits of trunk and crown of oak trees (Quercus robur L.) can be applied to crown class assessment. For this purpose, we used the principal component analysis (PCA) and nonlinear kernel principal component analysis (KPCA) based on measurable traits of trunk and crown, i.e., the height of the tree, the diameter at breast height, the length of the crown, and the field crown projection area. In total, we measured 286 mature trees in three oak stands located in western Poland. Results indicate that all chosen traits of trunk and crown allowed, though not always perfect, to assign the trees into given crown classes. The greatest contribution to crown class distinction had the diameter at breast height and the parameters of crown, i.e., and the field crown projection area. Furthermore, results show that the best method of assigning the trees into biosocial classes is the KPCA Gauss, considering the percentage explanation of the total variability, and KPCA Laplace, considering the visual division. In the latter, the multivariate analysis resulted in a similar crown class assignment as the field-assigned method. However, its application requires measurements that make it neither cheaper nor faster than a traditional crown class assessment. It indicates that a traditional field-assigned method, despite its subjectivity, should continue to be of great importance in forestry practice. Moreover, the alternative traits of trunk and crown can be a potentially useful statistical substitute for crown class assessment. Keywords: crown class, oak stand, trunk and crown traits, multivariate methods

Effects of Canopy and Multi-Epoch Observations on Single-Point Positioning Errors of a GNSS in Coniferous and Broadleaved Forests

Global navigation satellite systems (GNSS) can quickly, efficiently, and accurately provide precise coordinates of points, lines, and surface elements, plus complete surveys and determine various boundary lines in forest investigations and management. The system has become a powerful tool for dynamic forest resource investigations and monitoring. GNSS technology plays a unique and important role in estimating timber volume, calculating timber cutting area, and determining the location of virgin forest roads and individual trees in forests. In this study, we quantitatively analyzed the influence of crown size and observation time on the single-point positioning accuracy of GNSS receivers for different forest types. The GNSS located single points for different forest types and crown sizes, enabling the collection of data. The locating time for each tree was more than 10 min. Statistical methods were used to analyze the positioning accuracy of multi-epoch data, and a model was developed to estimate the maximum positioning errors under different forest conditions in a certain positioning time. The results showed that for a continuous positioning time of approximately 10 min, the maximum positioning accuracies in coniferous and broadleaf forests were obtained, which were 12.13 and 15.11 m, respectively. The size of a single canopy had no obvious influence on the single-point positioning error of the GNSS, and canopy density was proven to be closely related to the positioning accuracy of a GNSS. The determination coefficients (R2) in the regression analysis of the general model, coniferous forest model, and broadleaved forest model that were developed in this study were 0.579, 0.701, and 0.544, respectively. These results indicated that the model could effectively predict the maximum positioning error in a certain period of time under different forest types and crown conditions at middle altitudes, which has important guiding significance for forest resource inventories and precise forest management.

Analysis of Prosthetic Factors Affecting Peri-Implant Health: An in vivo Retrospective Study.

ObjectiveTo investigate and compare the various restorative and prosthetic parameters affecting peri-implant tissues’ health following dental implant placement and functional loading.MethodsA total of 484 dental implants (length>6mm, non-turned, 2–3 piece, titanium – Straumann) were evaluated for patients (male=271; female=213). Study variables such as patient’s age, gender, implant restoration/crown type, crown retention, and implant crown status were assessed against various periodontal parameters (periodontal pocket depth (PPD), plaque index (PI), bleeding on probing (BOP), gingival color, and crestal bone level). All the data were analyzed using the SPSS software.ResultsOut of all the investigated dental implants, 201 (42%) of the implants investigated presented with BOP > one-site of the peri-implant mucosa (peri-implant mucositis), 115 (23.76%) presented with peri-implant marginal bone loss. PPD value was significantly lower in good crown status (p<0.0001). Majority of the patients with good crown status had no plaque accumulation based on the PI scores (52.7%). Only 35% of the patients whose crown status was good were having BOP when compared with 65% who did not have any BOP recorded. Gingival color (pale pink and red) showed statistically significant association with crown type (porcelain fused to metal v/s all ceramic) (p=0.005). Most of patients with crown status good had no change in their radiographic findings (94%) compared to only 6% who had implant threads exposed (p<0.0001).ConclusionOptimal design of Implant prosthetic factors are vital for avoiding the development of peri-implant mucositis/peri-implantitis and must be considered during treatment planning while restoring dental implants.

Short Communication: Assessing the state and change of forest health of the proposed arboretum in Wan Abdul Rachman Grand Forest Park, Lampung, Indonesia

Abstract. Safe’I R, Latumahina FS, Dewi BS, Ardiansyah F. 2021. Short Communication: Assessing the state and change of forest health of the proposed arboretum in Wan Abdul Rachman Grand Forest Park, Lampung, Indonesia. Biodiversitas 22: 2072-2077. Forest health is the fundamental of sustainable forest management. As such, forest health needs to be continually monitored and maintained. This study assessed the state and change of forest health of the prospective arboretum in Wan Abdul Rachman Grand Forest Park (Tahura WAR), Lampung, Indonesia, aiming that the arboretum can serve for integrated conservation and education forest (Tahura War). This research used the Forest Health Monitoring (FHM) method by combining the parameters of vitality (i.e., tree damage and tree crown condition) and biodiversity (tree species diversity) across four Forest Health Monitoring plot clusters. The results showed there was a change in the state of forest health of the prospective arboretum in Tahura WAR. The first measurement showed that 50% of plot clusters had a status of bad, while 25% was moderate and 25% was good. The results of the second measurement showed that 50% of plot clusters had a status of moderate, while 25% was bad and 25% was good. This finding suggests that the prospective arboretum experienced changes toward better conditions in health status. Even so, it is still necessary to carry out regular forest health monitoring activities to determine trends.

Phosphite spray for the control of oak decline induced by Phytophthora in Europe

Forest decline induced by Phytophthora is a global phenomenon that affects many tree species. In central Europe, the health of Quercus robur has been declining due to various biotic and abiotic factors, since the 2000s. In drought-prone areas in the Mediterranean region, forests of Q. ilex show maintained tree mortality since the 1980s. The efficacy of potassium phosphite, applied as a foliar or trunk spray at a range of concentrations between 0 and 35%, was investigated over several years in four field trials with mature oaks. Specifically, Experiments 1 and 2, conducted on Q. robur in Poland indicated that aerial and trunk spray of 35% phosphite improved the crown condition of unhealthy trees. The efficacy of treatments was not dependant on the initial tree health condition, although its effects started earlier in trees that had lower crown transparency. Treatments did not alter the abundance and composition of edaphic and endophytic bacteria of trees. Moreover, aerial spray enhanced the N, P and Mg leaf content and induced the formation of fine roots without compromising the secondary growth of trees. In Experiment 3, conducted in Spain on Q. ilex, foliar spray did not improve the crown condition of trees. However, foliar spray of 0.56% phosphite induced twig growth in treated trees located on a southern exposure. Reduction of Phytophthora inoculum by the use phosphite was not observed. Our study provides the foundation for the development of a cost-effective management tool for Phytophthora in Europe and motivates future research into the optimization of treatments in Q. ilex and Q. robur.

Index measures for oak decline severity using phenotypic descriptors

Oak decline syndromes such as Acute Oak Decline (AOD) and Chronic Oak Decline (COD) are becoming increasingly prevalent and with this comes the need for more quantitative, sensitive and standardised visual oak health monitoring.Phenotyping protocols were developed to specifically measure oak decline severity and were based on a comprehensive set of simple to measure phenotypic descriptors. A total of 36 phenotypic measurements describing oak decline status included aspects of tree size, crown condition, the presence of biotic agents and a number of derived composite descriptors.Phenotypic measurements were collected from a total of 174 Quercus robur, surveyed from 9 sites across England and included healthy, AOD, COD and AOD trees in remission. Using these data, the Phenotypic Decline Index (PDI) and the Decline Acuteness Index (DAI) were developed to quantitatively describe and differentiate the acute and chronic oak decline severity spectrum. These decline indexes were derived from unsupervised random forest machine learning models, trained using the collected phenotypic data.The suitability of the decline indexes for describing decline severity and type were assessed by comparing decline index scores to manual decline status classifications along with an assessment of descriptor importance and contribution to the decline index models. Crown condition and trees size descriptors such as ‘composite crown volume’ contributed positively to the PDI. Trees with smaller crowns in poor condition had greater PDI values. Tree stature and the presence of stem bleeding contributed highly to the DAI, allowing differentiation between trees with AOD and COD syndromes. AOD trees had relatively larger stature and the presence of stem bleeding where as COD trees had small stature and stem bleeding was absent.The oak decline indexes are simple but sensitive measures of tree decline severity and allow easy comparisons of oak trees both spatially and temporally. These have the potential to provide useful tools for forest monitoring and management as well application to remote sensing and omics research.

A multiple‐lines‐of‐evidence approach for prioritising environmental watering of wetland and floodplain trees

AbstractLong‐lived vegetation is a key attribute of lowland river floodplains; yet dieback is increasingly being reported globally, with prior studies identifying salinity, drought and altered flow regimes as key stressors. In the Murray–Darling Basin (Australia), many floodplain/wetland areas have management strategies that aim to maintain the condition of floodplain tree communities. Environmental water delivery is a key tool used to achieve such outcomes. Currently, one of the primary tools for determining the need for environmental water delivery is a qualitative visual assessment of tree crown condition. To advance to more quantitative assessment and understanding of tree condition, we present a suite of techniques ranging from low‐cost, rapid visual assessment of tree crown condition to laboratory analysis of components of soil condition and in situ measurement of tree physiology. The aim is to address a number of key knowledge gaps on how to use the linkages between soil water availability ↔ tree physiology ↔ tree visual condition to quantitatively inform environmental water delivery decisions to meet management objectives. We have developed a multiple‐lines‐of‐evidence management assessment framework that presents a pathway to enable managers to improve prioritisation management actions. Furthermore, increased confidence in predicted outcomes should assist water holders and floodplain managers to optimise timing and maximise the benefits of environmental watering. Application of outcomes of this research will increase the efficiency of environmental water use.

TREE DAMAGE AND MISTLETOE IMPACT ON URBAN GREEN AREAS

ABSTRACT Green areas in cities provide several benefits to people, however, several biotic and abiotic agents affects the tree’s health. The main goals of this research were to identify tree damages and to assess the impact of mistletoe on dendrometric variables and the crown condition. Four thousand, seven hundred seventy-five trees were evaluated in 16 green areas of eight Mayoralties in Mexico City; each tree was labeled, and total tree height (Th), diameter at breast height (DBH), damage agents (up to three types), and the crown variables: Live crown ratio (Lcr), Crown dieback (Cdie), Mistletoe severity (Ms) and Crown position (Cpo) were recorded. Of the assessed trees, 3318 presented damage. For the type of damage 1, the mistletoes Cladocolea and Struthanthus showed an average incidence of 42%. For type 2, 20 agents and type 3, 11 were identified. Mechanical wounds, sucking insects, vandalism, and cankers were the most common damages. Based on the Principal Component Analysis (PCA), trees of all diameters and heights were infected, however, Struthanthus was associated with taller and larger diameter trees. Lcr was lower, and Cdie and Ms were higher in infected trees. About Cpo, dominant and codominant trees showed the highest levels of severity by mistletoe. The most affected tree genera were Ulmus and Populus (low Lcr and high Cdie and Ms). Cladocolea was found toward southern Mayoralties, and Struthanthus at the north. It is recommended to assess at least two types of damage on each tree, as this will provide a more complete picture of its health. This is the first study in Mexico on the impact of mistletoe on tree crown variables

Interaction between stem damage, crown vitality and growth performance of European yew in Central–East Europe

Abstract As long-lived, slow-growing tree species, European yew (Taxus baccata L.) has considerable potential for dendrochronological use. The increasing probability of decline and the worsening of yew health status endanger the species diversity of temperate forests. In 2015–2017, we sampled adult yew populations with scattered occurrence in limestone beech forests (Fagetum dealpinum), in which yew trees exhibit the top growth performance. Altogether, 150 trees were sampled (294 cores) at four localities. By using the general linear model, we investigated the interactions between stem and crown status, sex and growth performance of yew trees. Based on the previous results and innovative measures of competition and canopy closure, we explored the promotion of silviculture care for female over the male trees and formulated exact release cutting rules. The results demonstrate divergent growth trends between male and female trees and the pronounced negative effects of crown and stem damage on growth performance of European yew. Expected decreases in radial growth of damaged female trees in comparison with male ones is less confirmed. Despite this, making silvicultural treatments for females as a priority is recommendable. Our findings can improve the effectiveness of forest management and restoration activities in European temperate forests, where yew adults are threatened by the higher degree of shading and herbivory pressure.

The crown condition of Norway spruce and occurrence of symptoms caused by Armillaria spp. in mixed stands

Mixed stands are currently supported as effective management options to reduce forest vulnerability to climate change. However, our issues about benefits of mixtures, mechanisms of their incidence and conditions for their effectiveness have yet been only partly clarified. We assessed the crown condition of Norway spruce (Picea abies /L./ Karst) and occurrence of symptoms caused by Armillaria spp. on spruce in a small area in the Drahanská vrchovina Highlands (Czech Republic) in differently mixed stands in 2002 and 2019. We found that although the broadleaf abundance affected the total defoliation of Norway spruce, the effect was unstable in time. The observed effect of altitudinal zones and Norway spruce abundance on the occurrence of symptoms of Armillaria root rot in spruce was also unstable. The drought during recent four years and the implemented forestry measures (salvage and intermediate felling) can be reasons for the relationship instability. We did not identify any statistically significant relationship between tree species diversity (Simpson’s Index) and defoliation.

Spatial and temporal fuels changes in whitebark pine (Pinus albicaulis) from mountain pine beetle (Dendroctonus ponderosae)

Mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) causes extensive tree mortality in whitebark pine (Pinus albicaulis Engelm) forests. Previous studies conducted in lodgepole pine (Pinus contorta Douglas), Douglas-fir (Pseudotsuga menziesii (mirb.) Franco), and Engelmann spruce (Picea engelmanni Parry ex. Engelm) have shown that litter, duff, and 1-h (<0.64 cm) and 10-h (0.64–2.54 cm) time lag fuels are altered significantly from MPB outbreaks, while coarse woody fuels are affected over a longer time frame. MPB activity in conifer stands also alters foliar fuel moisture content over the course of the bark beetle rotation. This study evaluated changes to fine surface fuels and foliar fuel moisture in and under whitebark pine trees infested by MPB at two sites in Montana and Wyoming, USA. Fuel loads and foliar moisture were measured for crown condition classes of green trees (healthy), red trees (within two years since initial MPB attack with at least 50% of needles remaining), and gray trees (more than two years since attack with approximately 15% to 45% needles remaining). Tree locations and condition class were mapped using 2011, 2013, and 2015 NAIP imagery, and spatial point patterns were identified. Duff depths were significantly shallower beneath green trees (10.7–11.9 mm) than red (16.7–17.7 mm) and gray (13.9–16.1 mm) trees. Foliar fuel moisture content was altered dramatically across crown condition classes. Red needled trees had the lowest fuel moisture content, which was less than 18%. Point pattern hot spot analysis revealed increased (hot-spots) fuel hazard in trees 2–3 years post MPB attack, and decreased fuel hazard (cold-spots) in trees more than 3 years after MPB attack because foliage fell from trees and left larger diameter aerial fuels which were less likely to ignite. MPB-attacked trees were often clustered, and thus fuels hazard was not uniform across the landscape following MPB attack.

Earth Observation Based Monitoring of Forests in Germany: A Review

Forests in Germany cover around 11.4 million hectares and, thus, a share of 32% of Germany’s surface area. Therefore, forests shape the character of the country’s cultural landscape. Germany’s forests fulfil a variety of functions for nature and society, and also play an important role in the context of climate levelling. Climate change, manifested via rising temperatures and current weather extremes, has a negative impact on the health and development of forests. Within the last five years, severe storms, extreme drought, and heat waves, and the subsequent mass reproduction of bark beetles have all seriously affected Germany’s forests. Facing the current dramatic extent of forest damage and the emerging long-term consequences, the effort to preserve forests in Germany, along with their diversity and productivity, is an indispensable task for the government. Several German ministries have and plan to initiate measures supporting forest health. Quantitative data is one means for sound decision-making to ensure the monitoring of the forest and to improve the monitoring of forest damage. In addition to existing forest monitoring systems, such as the federal forest inventory, the national crown condition survey, and the national forest soil inventory, systematic surveys of forest condition and vulnerability at the national scale can be expanded with the help of a satellite-based earth observation. In this review, we analysed and categorized all research studies published in the last 20 years that focus on the remote sensing of forests in Germany. For this study, 166 citation indexed research publications have been thoroughly analysed with respect to publication frequency, location of studies undertaken, spatial and temporal scale, coverage of the studies, satellite sensors employed, thematic foci of the studies, and overall outcomes, allowing us to identify major research and geoinformation product gaps.

Leaf gas exchange and foliar macronutrients vary in Quercus bicolor but not Quercus phellos between a designed soil pavement system and open lawn

Structural soils are a type of designed soil intended to improve tree growth in the built environment by increasing the rooting volume available to trees underneath pavement. While urban trees can experience multiple environmental stressors, tree water relations and leaf nutrients are not well studied in structural soil systems. We examined leaf level gas exchange, foliar nutrient concentrations, and crown condition to evaluate the potential effects of water and nutrient related stressors in this setting. Located in Brooklyn, NY, USA, the study site included Quercus bicolor and Q. phellos planted in both sidewalk pits underlain with structural soil and in open lawn areas. Tree size measurements indicate that around 16–20 years post-installation, lawn trees have started to become larger than those in the sidewalk, though the size differences are comparatively small. Leaf level net photosynthetic assimilation and stomatal conductance of Q. bicolor were significantly lower in sidewalk trees compared to lawn trees in 2016. Yet no differences in gas exchange were observed for Q. phellos which suggests the two species likely have different water use strategies. Out of 27 elements measured in leaf tissue, Ca, K, Ba, and Sr were significantly lower in Q. bicolor sidewalk trees. Both species appeared to have elevated foliar concentrations of Na. For Q. phellos, sidewalk trees had significantly lower crown vitality (fine twig dieback) scores, though no differences were observed for Q. bicolor. These findings suggest Q. bicolor may be more sensitive to water and nutrient stress in the structural soil system compared to Q. phellos.

Tree vitality indicators revealed a rapid response of beech forests to the 2018 drought

Changes in regional and global hydrological cycles and temperature regimes will affect forest health, functioning and growth, and therefore their role in carbon (C) sequestration. A severe spring-summer drought hit large parts of central Europe in 2018 leading locally to premature leaf senescence in deciduous tree species. In late summer 2018 and 2019, we carried out a special survey on selected plots (n = 75) of the Swiss National Forest Inventory to detect whether beech (Fagus sylvatica L.) trees (n = 271) responded to the drought, and to evaluate possible lasting effects in the subsequent year. We concentrated on three vitality indicators: severe crown transparency (SCT), severe leaf browning (SLB), and growth in terms of basal area increment (BAI). In late summer 2018, we observed a frequency of beech trees affected by SLB and SCT significantly higher than in long-term baseline data. The most significant predictors of the occurrence of SLB and SCT were previous growth, species composition, tree size and precipitation deficit. Overall, BAI was significantly lower in 2018 compared to the 2010–2017 average. In particular, trees with both SLB and SCT grew significantly less than unaffected trees, with 40–100% lower median C increment. SCT, SLB and BAI largely recovered after more favorable weather conditions in 2019: almost no instances of SLB were recorded, and SCT was comparable to long-term baseline data. BAI in 2019 was significantly higher than in 2018 and 2010–2017, and weakly related to the crown condition recorded in late summer 2018. We conclude that SCT and SLB recorded in late summer 2018 indicated rapid, drought-induced canopy deterioration of beech, associated with an immediate reduction in BAI and tree-level carbon sequestration. These effects were, however, mainly temporary for most of the investigated beech trees. Since the standard long-term forest health assessment was not able to capture the above signals, we discuss opportunities for adapting its design without jeopardizing data comparability over time.

Category Classification of Tree States Using Visual Data Based on Fuzzy Logic

Introduction: A reliable assessment of tree condition directly affects the planning of economic indicators for the use of forest resources and ecological actions for forest protection. Therefore, the correct evaluation of the sanitary state of forest is very important. At present, the decisions that forest pathologists make about classifying trees or forest areas are based on visual inspection and their subjective knowledge about the tree features. Purpose: Development of a method for classifying the condition of a tree in terms of its crown density degree and other features, based on fuzzy logic with characteristic functions for linguistic variables such as “Crown density”, “Annual branch growth”, “Bark falling off” or “Shrinking branches”. Results: The proposed method classifies the tree condition using pine as an example. The method consists in preliminary image processing, including the removal of background objects, extraction of texture features as extended binary patterns, and application of a specially designed controller based on fuzzy logic. We propose four types of linguistic variables, with their respective terms. For these variables, characteristic functions are specified in tabular form and then approximated by smooth functions. A fuzzy logic controller allows you to obtain an objective assessment of the tree crown condition. Experimental studies confirm the effectiveness of the developed method. Practical relevance: The intelligent system of classifying the tree condition according to visual data can provide a significant support to plantation survey specialists. The proposed method allows you to improve the quality of forest monitoring, minimize the influence of human factor, and organize the forest protection in the best possible way.

Quali-quantitative diagnosis and urban tree map in Marajoara neighborhood in the city Teófilo Otoni – MG

Urban afforestation is really important in urban centers, however, few Brazilian cities have effective planning for the afforestation of their public roads. This paper aims to diagnose a situation of urban afforestation in the Marajoara neighborhood, located in the city of Teófilo Otoni - MG. For this diagnosis, the data were collected using a questionnaire with a qualitative and quantitative assessment and mapping of adult trees, registering 324 trees. The phytosanitary state, size, root problems, need for pruning, crown status, interference from trees on public roads and conflicts with the electrical systems of the streets were observed; The Afforestation Index measured by Kilometer of afforested sidewalk in the city of Teófilo Otoni presented a value classified as insufficient (20.72). It is recommended for Teófilo Otoni an articulated planning between the City Hall and a local energy concessionaire, so that urban afforestation can be developed effectively with techniques for installation and maintenance of trees.