Tree Damage Research Articles

Detection of Fir Trees (Abies sibirica) Damaged by the Bark Beetle in Unmanned Aerial Vehicle Images with Deep Learning

Invasion of the Polygraphus proximus Blandford bark beetle causes catastrophic damage to forests with firs (Abies sibirica Ledeb) in Russia, especially in Central Siberia. Determining tree damage stage based on the shape, texture and colour of tree crown in unmanned aerial vehicle (UAV) images could help to assess forest health in a faster and cheaper way. However, this task is challenging since (i) fir trees at different damage stages coexist and overlap in the canopy, (ii) the distribution of fir trees in nature is irregular and hence distinguishing between different crowns is hard, even for the human eye. Motivated by the latest advances in computer vision and machine learning, this work proposes a two-stage solution: In a first stage, we built a detection strategy that finds the regions of the input UAV image that are more likely to contain a crown, in the second stage, we developed a new convolutional neural network (CNN) architecture that predicts the fir tree damage stage in each candidate region. Our experiments show that the proposed approach shows satisfactory results on UAV Red, Green, Blue (RGB) images of forest areas in the state nature reserve “Stolby” (Krasnoyarsk, Russia).

Linking tree growth rate, damage repair, and susceptibility to a genus-specific pest infestation

Pest preference and subsequent susceptibility of a host individual is likely related to previous growth patterns in that host. Emerald ash borer (Agrilus planipennis Fairmaire) is a pestiferous beetle introduced to North America from Asia. While all species of ash are susceptible to attack, some individual trees appear to survive infestation. We selected ash trees in southeastern Michigan, collected cores and categorized trees as high tolerance to emerald ash borer attack (high overall health, low crown dieback), low tolerance (low overall health, high crown dieback) and intermediate tolerance (in-between the other categories). We artificially wounded trees and measured wound closure after 3 years. Ring width indices were not correlated between high and low tolerance trees. Regression slopes comparing growth and years were significantly different between the three tolerance categories, with high tolerance trees having the steepest slope. Wound closure was greatest in high tolerance trees. High tolerance trees demonstrating more rapid (steeper regression slope), consistent (lower variance), and effective (greater wound closure) growth. Those vigorously growing trees likely had more capacity to repair damage caused by emerald ash borer, leading to healthier trees in our categorization. Linking previous host growth patterns to health may have implications related to identifying individual trees potentially tolerant to attack.

Urban trees management methods and their suitability for creating databases

The number of decisions permitting the removal of trees in cities is increasing every year, which suggests long-term negligence, or rather insufficient funds for proper management of urban forests. Lack of appropriate tools causes difficulties in the decision-making process. This problem is especially important in a situation of increased pressure exerted by residents to remove trees, mainly due to the safety reasons. An essential element in maintaining the proper tree management in a city is to improve management systems by applying comprehensive methods and tools. For this reason, many methods are used to support the inventory and identification of dangerous trees. The presented research is a response to the need for unification of management systems based on the most effective and proven methods of defining the resource, health and static condition, value, assessment of tree life expectancy or tree damage. Such a multilateral approach can improve the safety and management of urban forests. The results of the presented analyses led to the formulation of objective guidelines for the urban tree management standards.

Видове різноманіття та особливості поширення дереворуйнівних грибів у парку культури і відпочинку імені Михайла Чекмана міста Хмельницького

Наведено результати дослідження видового складу дереворуйнівних грибів у Парку культури і відпочинку ім. Михайла Чекмана міста Хмельницького та біоекологічні особливості їх поширення. У Парку культури і відпочинку ім. Михайла Чекмана виявлено 29 видів дереворуйнівних грибів, які поширені на 14 видах деревних порід. Найпоширенішими виявилися таки види дереворуйнівних грибів: трутовик облямований, б'єркандера обвуглена, б'єркандера димчаста, трутовик несправжній та стереум жорстковолосистий. Ці види дереворуйнівних грибів трапляються майже на всіх деревних видах парку, які пошкоджені дереворуйнівними грибами. Ці гриби трапляються поодиноко на видах дерев I та ІІ стадій деструкції, дуже рідко – на III стадії. Встановлено деревні породи, які найбільше піддаються ураженню дереворуйнівними грибами, це такі види: береза повисла, ясен звичайний, верба біла, тополя чорна та дуб звичайний. Доведено, що роль дереворуйнівних грибів у міських насадженнях негативна. Більшість видів дереворуйнівних грибів спричиняють різноманітну гниль. Такі дерева довгий час не мають зовнішніх ознак ослаблення. Встановити вражені дерева дереворуйнівними грибами можна тільки за наявністю плодових тіл. Запропоновано основні методи боротьби з дереворуйнівними грибами у парку.

PENILAIAN KESEHATAN KEBUN BENIH SEMAI Pinus merkusii DENGAN METODE FHM (FOREST HEALTH MONITORING) DI KPH SUMEDANG Health Assessment for Seedling Seed Orchard of Pinus merkusii Using FHM (Forest Health Monitoring) Method in KPH Sumedang

Pine (Pinus merkusii) is tree species that provides timber and gum rosin. To meet the needs of wood and non wood (gum rosin) products, planting by using superior or high quality seeds are needed. Seed procurements for planting are obtained from seedling seed orchard (SSO). However, Cijambu’s SSO was attacked by pine woolly aphid (Pineus boerneri). Therefore, assessment of Cijambu’s SSO needs to be done to evaluate the severity pest attacks that could affect to the quality and the quantity of seed production. Forest Health Monitoring (FHM) method is one of the methods to assess the health level of a stand. The number of trees found in all cluster plots in Cijambu’s SSO were 270 trees. Based on the value of the VCR (Visual Crown Rating), the trees located in all cluster plot have health level between low to high. Based on the value of the VCR showed 38.52% (104 trees) having VCR’s value was high, 49.26% (133 trees) having VCR’s value was middle; 12.22% (33 trees) having VCR’s value was low; and no tree having very low VCR’s value. The average of VCR’s value in all cluster plots were 3.25 and classified as middle health. Based on the value of TDLI (Tree Damage Level Index) from 270 trees in all cluster plot showed that 189 trees (70.00%) in healthy condition; 69 trees (25.56%) in slight damage condition; 11 trees (4.07%) in middle damage condition; and 1 tree (0.37%) in heavy damage condition. The value of damage in all cluster plots (ALI) was 261.22 and classified as in health condition. The trees located in all cluster plots were mostly suitable to be seed sources as 242 trees (89.63%), while 28 trees (10.37%) were not suitable for seed sources.Keywords: Forest Health Monitoring, Pinus merkusii, seedling seed orchard, Tree Damage Level Index, Visual Crown Rating

Mechanical properties of Japanese black pine (Pinus thunbergii Parl.) planted on coastal sand dunes: resistance to uprooting and stem breakage by tsunamis

Given that Japanese black pine trees (Pinus thunbergii Parl.) are predominant in the coastal forests of Japan and are part of the defence structure against tsunamis, the quantification of their resistance to tree damage is necessary. The resistance of Japanese black pine to uprooting and stem breakage and its bending properties were estimated by a tree-pulling test and bending test of green logs in conjunction with the published literature. A general equation to estimate the critical turning moment for uprooting was developed using diameter at breast height and tree height as predictor variables. For moduli of elasticity and rupture of stems (MOE and MOR), medians [5th and 95th percentile values] were 5.41 [3.78, 6.82] GPa and 35.0 [28.7, 41.8] MPa, respectively. With the obtained critical turning moment and MOR, the critical tsunami water depth was estimated by numerical simulations using modelled trees. The numerical simulations revealed that Japanese black pine trees on coastal sand dunes tended to be more vulnerable to uprooting than stem breakage, with taller and more slender trees showing less resistance to stem breakage. The results on the mechanical properties of Japanese black pine are of use to those in the wood science community as well as coastal managers who need to know the mechanical strength of Japanese black pine to help evaluate their resistance against tsunamis.

Ants, wind, and low litter deposition contribute to the maintenance of fire-protective clearings around Jeffrey pine (Pinus jeffreyi)

In Jeffrey pine (Pinus jeffreyi) forests, which once supported a frequent, mostly low severity fire regime, fire suppression has led to notable changes in forest structure and fuel loads. In parts of California, prescribed fire has been used to decrease fuel loads and reduce the risk of high intensity fire in these forests. Previous work has shown that circular litter-free clearings form around Jeffrey pine trees following prescribed burns and that they can reduce tree damage and potentially increase the chance of survival in a subsequent wildfire. In this study we aim to determine the factors responsible for maintaining clearings around trees after a fire occurs. Using a set of field experiments and observational studies, we show that a combination of natural processes, including reduced litter deposition near trees, and the movement of needles away from trees by ants (Formica sibylla) and wind, reduce the amount of litter near trees and likely contribute to the long-term maintenance of clearings. Stem flow resulting from rare heavy rain events also appears to play a role in clearing maintenance. All of the abiotic factors investigated interact with the physical structure of the tree to remove pine needles from the bases of trees, but ants move needles independently to facilitate clearing maintenance and indirectly enhance tree fitness when fires occur. Given how generally common F. sibylla is in Jeffrey pine habitat and the relative stability of the abiotic processes that also contribute to maintaining clearings (wind, precipitation, and needle fall), we may expect to see clearings form in other Jeffrey pine forests after prescribed fires are introduced.

Interpreting effects of multiple, large-scale disturbances using national forest inventory data: A case study of standing dead trees in east Texas, USA

Understanding the impacts of large-scale disturbances on forest conditions is necessary to support forest management, planning, and policy decision making. National forest inventories (NFIs) are an important information source that provide consistent data encompassing large areas, covering all ownerships, and extending through time. Here we compare how temporal aggregation approaches with NFI data affects estimates of standing dead trees as these respond to extreme disturbance events. East Texas was selected for this study owing to the occurrence of three significant disturbance events in a short span: Hurricane Rita in 2005, Hurricane Ike in 2008, and a historic drought in 2011. Wide-spread tree damage and mortality were reported after each disturbance and estimates of standing dead trees were used as the inventory variable for assessment. In the NFI of the US, the plot network is systematically divided into panels and one panel is measured each year. A measurement cycle is completed when all panels have been measured, which varies between 5 and 10 years depending on the region. Using the standard estimation approach of the US NFI, we computed population estimates using data from the full set of panels (FSP), multiple sets of panels (MSP), and single set of panels (SSP). For estimation, a single plot observation is computed from the most recent measurement of the plot that does not exceed the estimate year. Because one panel is measured per year, FSP and MSP estimates will necessarily consist of plot observations whose measurements were collected over a number of years. The SSP estimate is computed from one panel and thus all the plot observations are based on measurements collected over one year. We found that interpretations of disturbance event impacts varied depending on which sets of estimates were considered. All sets of estimates suggested a large and significant drought impact. However, differences existed among the estimates in the timing and magnitude of the impacts. The FSP estimates showed clear lag bias and smoothing of trends relative to the SSP estimates. MSP estimates were intermediate between FSP and SSP estimates. Differences in Hurricane Rita impacts were also observed between sets of estimates. Evidence of a net impact on standing dead trees following Hurricane Ike was weak among all sets of estimates. Given the potential for lag bias and smoothing, we recommend that SSP and MSP estimates be considered along with FSP estimates in assessments of large-scale disturbance impacts on forest conditions.

Logging damage and injured tree mortality in tropical forest management

AbstractUsing insights from the forest ecology literature, we analyze the effect of injured trees on stand composition and carbon stored in above‐ground biomass and the implications for forest management decisions. Results from a Faustmann model with data for a tropical forest on Kalimantan show that up to 50% of the basal area of the stand before harvest can consist of injured trees. Considering injured trees leads to an increase in the amount of carbon in above‐ground biomass of up to 165%. These effects are larger under reduced impact logging than under conventional logging. The effects on land expectation value and cutting cycle are relatively small. The results suggest that considering injured trees in models for tropical forest management is important for the correct assessment of the potential of financial programs to store carbon and conserve forest ecosystem services in managed tropical forests, such as reducing emissions from deforestation and forest degradation and payment for ecosystem services.Recommendations for Resource ManagersConsidering the role of injured trees is important for managing tropical forestsThese trees can cover up to 50% of basal area and contain more than 50% of the carbon stored in above‐ground biomassReduced impact logging leads to a larger basal area of injured trees and more carbon stored in injured trees than conventional loggingInjured trees play an important role when assessing the potential for carbon storage in the context of payment for forest ecosystem services.

Damage Diversity as a Metric of Structural Complexity after Forest Wind Disturbance

This study presents a new metric for quantifying structural complexity using the diversity of tree damage types in forests that have experienced wind disturbance. Structural complexity studies of forests have to date not incorporated any protocol to address the variety of structural damage types experienced by trees in wind disturbances. This study describes and demonstrates such a protocol. Damage diversity, defined as the richness and evenness of types of tree damage, is calculated analogously to species diversity using two common indices, and termed a ‘Shannon Damage Heterogeneity Index’ (Sh-DHI) and an inverse Simpson Damage Heterogeneity Index (iSi-DHI). The two versions of the DHI are presented for >400 plots across 18 distinct wind disturbed forests of eastern North America. Relationships between DHI and pre-disturbance forest species diversity and size variability, as well as wind disturbance severity, calculated as the fraction of basal area downed in a wind disturbance event, are examined. DHIs are only weakly related to pre-disturbance tree species diversity, but are significantly positively related to pre-disturbance tree size inequality (size diversity). Damage diversity exhibits a robust curvilinear relationship to severity; both versions of the DHI show peaks at intermediate levels of wind disturbance severity, suggesting that in turn structural complexity may also peak at intermediate levels of severity.

The effect of pollutant fog deposition on the wood anatomy of subalpine Norway spruce

In recent decades, significant changes have been observed in the atmospheric pollutant emissions and deposition in the mountain regions of Central Europe. Pollution caused significant deforestation, but the level of tree damage differs, even between neighboring locations. Thus, it is particularly important to examine the relationships between pollutant deposition rate and detrimental changes in the subalpine spruce ecosystems, and to correlate these with the intensity and structure of pollutant deposition. Radial wood cores were extracted at breast height from trees located in different montane areas: the Sudetes and both Western and Eastern Carpathians. Specific features of the secondary xylem, i.e., annual ring width as well as the width and lumen of early- and latewood tracheids, were analyzed for three decades: before the intense of environmental pollution (1950–1960), during essential stage of the ecological disaster (1980–1990) and after cessation of pollution (2000–2010). The narrowest annual rings and earlywood tracheids were formed in the 1980s in areas where fog was the main source of the pollutant deposition. In conclusion, it has been shown that fog could be an important factor increasing the destructive role of pollutants on wood formation. It was manifested in decreasing of cambial activity resulting in formation of narrower annual rings as well as in reduction in radial dimensions of earlywood tracheids.

Diplodia Tip Blight on Its Way to the North: Drivers of Disease Emergence in Northern Europe.

Disease emergence in northern and boreal forests has been mostly due to tree-pathogen encounters lacking a co-evolutionary past. However, outbreaks involving novel interactions of the host or the pathogen with the environment have been less well documented. Following an increase of records in Northern Europe, the first large outbreak of Diplodia sapinea on Pinus sylvestris was discovered in Sweden in 2016. By reconstructing the development of the epidemic, we found that the attacks started approx. 10 years back from several isolated trees in the stand and ended up affecting almost 90% of the trees in 2016. Limited damage was observed in other plantations in the surroundings of the affected stand, pointing to a new introduced pathogen as the cause of the outbreak. Nevertheless, no genetic differences based on SSR markers were found between isolates of the outbreak area and other Swedish isolates predating the outbreak or from other populations in Europe and Asia Minor. On a temporal scale, we saw that warm May and June temperatures were associated with higher damage and low tree growth, while cold and rainy conditions seemed to favor growth and deter disease. At a spatial scale, we saw that spread occurred predominantly in the SW aspect-area of the stand. Within that area and based on tree-ring and isotope (δ13C) analyses, we saw that disease occurred on trees that over the years had shown a lower water-use efficiency (WUE). Spore traps showed that highly infected trees were those producing the largest amount of inoculum. D. sapinea impaired latewood growth and reduced C reserves in needles and branches. D. sapinea attacks can cause serious economic damage by killing new shoots, disrupting the crown, and affecting the quality of stems. Our results show that D. sapinea has no limitations in becoming a serious pathogen in Northern Europe. Management should focus on reducing inoculum, especially since climate change may bring more favorable conditions for this pathogen. Seedlings for planting should be carefully inspected as D. sapinea may be present in a latent stage in asymptomatic tissues.

Fungi associated with Cryphalus rhusi (Scolytinae; Coleoptera) infesting lacquer tree, Toxicodendron vernicifluum

ABSTRACTWe have examined the fungi associated with the scolytid bark beetle, Cryphalus rhusi, which infests the lacquer tree Toxicodendron vernicifluum. The fungi were also evaluated for pathogenicity in T. vernicifluum as a step toward clarifying the potential of the beetle for tree damage. Three fungal species, a Yamadazyma sp., a Fusarium sp., and Penicillium pinophilum were isolated from adult beetles that had emerged from branches. Of these, the Yamadazyma sp. appeared to be a close associate of the beetle, since it was isolated from all individuals used in the study, while the others were much less frequent. Pathogenicity tests revealed that the Fusarium sp. caused slightly larger lesions (by 2 mm) than the negative controls, whereas the Yamadazyma sp. did not cause any symptoms. We conclude that C. rhusi, with its associated fungi, is not likely to be a serious pest for T. vernicifluum.

Initial hydraulic failure followed by late-stage carbon starvation leads to drought-induced death in the tree Trema orientalis

Drought-induced tree death has become a serious problem in global forest ecosystems. Two nonexclusive hypotheses, hydraulic failure and carbon starvation, have been proposed to explain tree die-offs. To clarify the mechanisms, we investigated the physiological processes of drought-induced tree death in saplings with contrasting Huber values (sapwood area/total leaf area). First, hydraulic failure and reduced respiration were found in the initial process of tree decline, and in the last stage carbon starvation led to tree death. The carbohydrate reserves at the stem bases, low in healthy trees, accumulated at the beginning of the declining process due to phloem transport failure, and then decreased just before dying. The concentrations of non-structural carbohydrates at the stem bases are a good indicator of tree damage. The physiological processes and carbon sink-source dynamics that occur during lethal drought provide important insights into the adaptive measures underlying forest die-offs under global warming conditions.

A New Architectural Perspective on Wind Damage in a Natural Forest

Wind damage is a significant driver of forest structure, ecology and carbon cycling in both temperate and tropical regions, but most of the literature on wind damage focusses on conifer plantations. Previous studies in broadleaf forests have been limited by a lack of data on tree architecture, a problem that is potentially overcome by terrestrial laser scanning. Here we apply novel approaches to estimate the critical wind speeds at which trees will break in a temperate, deciduous forest plot in Wytham Woods, UK, using a combination of field data and finite element analysis. Ash trees (Fraxinus excelsior) tend to have lower critical wind speeds than sycamores (Acer pseudoplatanus), while English oak (Quercus robur) are the most mechanically robust. This difference in critical wind speed is driven by tree size and architecture, rather than material properties. We observe a trade-off between critical wind speed and growth rate, both within and across species. Our estimates of critical wind speeds from field data are lower in summer than in winter, emphasizing the importance of the spring and autumn transition periods. Of the three species we studied, those with lower critical wind speeds drop their leaves earlier in autumn, suggesting that the timing of leaf shedding may be under selection pressure to minimize risk of tree damage from winter storms. These results are tentative, but also intriguing and intuitive.

Not just urban: The Formosan subterranean termite, Coptotermes formosanus, is invading forests in the Southeastern USA

Coptotermes formosanus, known in its native China as the ‘House White Ant’, was introduced to the southeast USA likely in the 1950s, where it is known as the Formosan subterranean termite. In the USA it is best known as a pest of buildings in urban areas, however C. formosanus also attacks live trees along streets and in urban parks, suggesting it may be able to invade forests in the USA. A survey of 113 forest patches around Charleston South Carolina and New Orleans Louisiana, where C. formosanus was first recorded, found that 37% and 52%, respectively, were infested. Resistograph measurement of internal hollows in tree trunks in forest patches infested with C. formosanus found infested sites contained more and larger hollows compared with non-infested sites. Compared with forest patches free of C. formosanus, infested patches had 32% more trees with hollows in Charleston, and 115% more in New Orleans. Similarly, compared with patches free of C. formosanus, hollows were 2–3 times larger in infested patches in Charleston, and 2–6 times larger in New Orleans. Quercus (oak) and Acer (maple) were the most damaged trees in Charleston, whereas Carya (bitternut hickory), Taxodium (bald cypress), Nyssa (blackgum) and Liquidamber (sweetgum) were the most damaged in New Orleans. As termite damaged trees are more likely to die, these differing damage levels between tree species suggests that C. formosanus may alter community structure in US forests.

Effect of skid trail curvature on residual tree damage

ABSTRACTSoil disturbances are unavoidable in ground-based skidding operations and it is well-known that the extent and severity of disturbances increase with increasing traffic frequency of harvesting equipment and soil conditions (e.g. soil moisture at the time of harvesting). It is unclear, however, how different traffic intensities and soil moisture contents affect the extent, size and intensity of damage inflicted upon residual trees and how these factors might further interact with the layout of skid trails. Skid trail layout in this study is concerned with the horizontal course of the trail that encompasses straight sections and curves of different deflection angles (i.e. narrower and wider curves). Due to expected rolling of logs and vehicle off-tracking in curves, we hypothesised that damage to residual trees would be greater in curves than on straight sections of skid trails and that damage would be greatest in the narrowest curves. We further hypothesised that the relationship between tree damage and curvature would hold regardless of traffic intensity and soil condition. To test these hypotheses, we conducted a survey of the residual stand damage caused by ground-based skidding operations for different trail curvatures and traffic intensities at two Hyrcanian forest sites in northern Iran with different soil conditions. The studied treatment combinations included three curvatures of the skid trail (i.e. narrow curve with a deflection angle of 60°–75°, wide curve with a deflection angle of 110°–130°, no curve (straight trail)), and three traffic frequencies (low, medium and high traffic intensity) of a rubber-tyred cable skidder operated on a clay soil with 18% soil moisture content (Site 1) and a clay-loam with 33% soil moisture content (Site 2). The percentage of damaged trees varied between 45% (Site 1) and 68% (Site 2). The results showed that the number of damaged trees as well as the distance from the skid trail edge to which trees were damaged increased significantly at both sites with increasing traffic frequency, increasing curvature (i.e. narrowing curve) and their interaction. Further, location, size and intensity of damage to residual trees varied significantly with curvature, traffic intensity and soil condition. At each traffic frequency, narrow curves exhibited more damaged trees and damaged trees were found at greater distances to the edge of the skid trail than in wide curves. The average damage area was 86 cm2 and 125 cm2 in Sites 1 and 2, respectively. The significant effect of trail curvature on the location, size and intensity of damage of residual trees has major implications for the design of a skid trail system capable of preserving residual tree quality.

Analysis and Extent of Santa Fe River Flooding in North Florida Attributed to Rainfall and Wind Damage Associated with Hurricane Irma

The Santa Fe River (SFR) is within the north Florida area of the regional Floridan aquifer system. The extent of recent flood damage in the SFR and tributaries in Bradford County has been attributed to rainfall and wind damage to trees associated with Hurricane Irma, September 2017. Implications of the determined cause of a disaster can include the allocation of disaster relief funds. Bradford County, Florida obtained approximately $2.5 million from the United States Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) for emergency flood abatement assistance and $255,875 from the Suwannee River Water Management District (SRWMD), combined with $13,750 in-kind match provided by the county, based on the attributed cause of that damage to rainfall and winds from Hurricane Irma. On January 2, 2018, Bradford County commissioners also approved grant applications to the SRWMD for $2.2 million for Alligator Creek Flood Mitigation and for $90,250 for Hampton Lake Canal to Santa Fe River Flood Mitigation, requiring in-kind matches from the county of $110,000 and $4750, respectively. Our study analyzed historical precipitation data for the SFR Basin and headwaters from 1895 through 2017 and recorded discharge and gage heights from the United States Geological Survey (USGS) to evaluate that presumed cause of flood damage in that basin and to provide a better understanding of historical relationships between precipitation, gage data and flooding in that basin. Recorded USGS peak gage height and Digital Elevation Models (DEMs) also were used to illustrate the lateral extent and relative depth of flooding associated with an extreme precipitation event in the lower SFR vicinity of O’Leno State Park. Finally, we evaluated the condition of the trees in the SFR Basin as an indicator of long-term anthropogenic groundwater alterations. Those data and analyses did not support the conclusion that Hurricane Irma was the only cause of the magnitude and extent of SFR flooding and tree damage in Bradford County and adjacent counties. Other contributors to stream flow in the SFR basin include heavy mineral mining wastewater discharges that have exceeded the maximum discharge volume of “40 million gallons a day” (MGD) under the National Pollutant Discharge Elimination System (NPDES) permit issued by the Florida Department of Environmental Protection (FDEP) to the Chemours Company TT LLC (Chemours, formerly DuPont) for Trail Ridge mining operations. The magnitude of those discharges suggests that those discharges and extensive Trail Ridge mining in Baker, Bradford, Clay, and Duval Counties contributed to the flooding and were a factor in the tree destruction in the SFR Basin.

Dinamika Populasi dan Kerusakan Pohon Tempat Bertengger Kalong (Pteropus vampyrus) di Kebun Raya Bogor

ABSTRACT The study on population dynamic and roosting trees damage by flying fox was conducted for 16 months (March 2008-June 2009) in Bogor Botanical Garden. Recording of individual flying fox was carried out by use direct observation in the roosting trees habitat at 9.00-15.00, with one replication every week. The result indicated that in 2008 the total flying fox were 420 individuals and in 2009 were 563 individuals (160 juveniles, 218 adult females and 185 adult males). The natality and mortality rate in this location is 0.0214 and 0.0099 respectively. The flying fox population growth can be predicted using exponential equation is N(t+1)=563(1.8395)t. The study also indicated that in the KRB there are 9 individual trees which are the main perch, 2 individual trees of Pterodotus alata, Pterocarpus indicus, and Shorea leprosula, and each 1 individual tree of the species Dipterocarpus cornutus, Ficus drupacea, and Syzygium syzygioides. The extent of damage to the tree where the perch is very dependent on the diameter of the canopy, bat population size in one tree, and time periods per roosting season. Keywords: Population Dynamic, Flying Fox (Pteropus vampyrus), Bogor Botanical Garden

An IoT Tree Health Indexing Method Using Heterogeneous Neural Network

Urban trees provide essential ecosystem services on regulating temperature and humidity, filtering urban pollutants, and improving air quality. However, the increasing number of urban trees put pressure on maintenance and public safety. The total compensatory value of the trees, consisting of inspection, maintenance, and settlement of tree damages, is more than $2 trillion USD. At this point in time, there is no known research on manifesting guidance on automated tree health assessment. The Internet-of-Things (IoT) proliferates the deployment of wireless sensors and networks. A concept of the IoT trees is raised to implement various sensors on the trees for automated health monitoring and assessment. In this paper, an urban tree health index (UTHI) is first developed to indicate the health of urban IoT trees. The index will facilitate preventive measures on urban trees. To construct the indexing model, seven (7) dynamic (time-series) features and seven (7) static features are extracted to explore the ambient effects on urban tree health. Afterward, a heterogeneous neural network (HNN) for UTHI modeling is developed to adopt the heterogeneous feature structure. In HNN, the dynamic features are analyzed in the gated recurrent unit (GRU) layer and the static features are analyzed in a hidden layer. The novel fusion layer then aggregates the outputs computed from those layers and further explores unseen correlations among all features. The experimental result verifies that the HNN-based modeling achieves high accuracy and model fitness with the error rate of less than 5%. In addition, the HNN achieves 34% to 66% improvement of accuracy in comparison with the other machine learning algorithms. The supremacy of the developed model is that all indexing features can be predefined or monitored by the IoT sensors, thus rendering an automated and economic urban tree management.