Characteristics of Trees Infested by the Invasive Primary Wood-Borer Aromia bungii (Coleoptera: Cerambycidae)

The expanding distribution and tree damage of the invasive, primary wood-borer Aromia bungii (Coleoptera: Cerambycidae), which kills trees of the Rosaceae family, is a problem in intruded areas. However, the tree characteristics associated with infestation by A. bungii, which are useful for early detection or prioritizing preventive measures, are not well examined. We investigated the presence or absence of tree damage (response variable) in pre- and post- surveys along with tree characteristics (four explanatory variables; bark roughness, size, species, and vigor) on monitoring trees in uninvaded sites (survey for the first trees to be damaged) and already invaded sites (survey for the next trees to be damaged). We evaluated the variables using generalized linear mixed models for each site (i.e., a first trees model and a next trees model). Three tree characteristics (bark roughness, size, and vigor) were included as explanatory variables in both best models, indicating that trees with rough surface bark, large in size, and weakened conditions were more susceptible to A. bungii infestation. The reasons for the difference between the two models (species was only chosen in the next trees model) will be considered in our future work.

Predicting Risks of Severe Windstorm Damage to Southeastern U.S. forests

ContextThe southeastern U.S. experiences tornadoes and severe thunderstorms that can cause economic and ecological damage to forest stands resulting in loss of timber, reduction in short-term carbon sequestration, and increasing forest pests and pathogens. ObjectivesThis project sought to determine landscape-scale patterns of recurring wind damages and their relationships to topographic attributes, overall climatic patterns and soil characteristics in southeastern forests. MethodsWe assembled post-damage assessment data collected since 2012 by the National Oceanic and Atmospheric Administration (NOAA). We utilized a regularized Generalized Additive Model (GAM) framework to identify and select influencing topographic, soil and climate variables and to discriminate between damage levels (broken branches, uprooting, or trunk breakage). Further, we applied a multinomial GAM utilizing the identified variables to generate predictions and interpolated the results to create predictive maps for tree damage. ResultsTerrain characteristics of slope and valley depth, soil characteristics including erodibility factor and bedrock depth, and climatic variables including temperatures and precipitation levels contributed to damage severity for pine trees. In contrast, valley depth and soil pH, along with climactic variables of isothermality and temperature contributed to damage severity for hardwood trees. Areas in the mid-south from Mississippi to Alabama, and portions of central Arkansas and Oklahoma showed increased probabilities of more severe levels of tree damage. ConclusionsOur project identified important soil and climatic predictors of tree damage levels, and areas in the southeastern U.S. that are at greater risk of severe wind damage, with management implications under continuing climate change.

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

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

Analysis of internal factors affecting the health condition of mangrove forests in the coastal area of East Lampung Regency

The surrounding community widely uses mangrove forests as a fulfillment of life. This requires an efforts to preserve the mangrove forest so that no damage occurs. This study aimed to determine the internal factors that affect the health condition of mangrove forests. The research method used to obtain internal factor data is by measuring the ecological indicators of forest health using the Forest Health Monitoring (FHM) method, then the data is processed by the Multiple Regression Analysis method using SPSS 20 through data on internal factors of mangrove forest health which are analyzed for their effect on health conditions of the mangrove forest. The results showed that the significant value of the regression was 0.008 ((α = 0.05) > 0.008), this means that simultaneously the independent variables (tree damage, crown damage, Cation Exchange Capacity-CEC, and biodiversity have an effect on the dependent variable (mangrove forest health) at the level of = 5%. Furthermore, through individual regression coefficients from internal factor data, it is found that the internal factors of biodiversity indicators in measurements 1 and 2 and crown conditions in the second measurement do not affect forest health conditions. Therefore, this research concludes that the internal factors that affect the level of forest health in the first measurement are vitality indicators (tree damage/cluster Plot Index-CLI and crown condition) and site quality indicators (CEC). Meanwhile, in the second measurement, there was a change in the crown condition parameters, which did not significantly affect forest health.

Short duration overnight cattle kraaling in natural rangelands leads to increased tree damage by elephants

Elephants are attracted to nutrient hotspots created through short duration overnight cattle corralling (hereafter kraaling) in natural rangelands at Debshan, a mixed cattle-wildlife private ranch in central Zimbabwe, causing severe tree damage. We determined the effect of age of nutrient hotspot (i.e., time after kraal use) on elephant use and the extent of tree damage. Elephant use and tree damage were assessed in nutrient hotspots of varying ages (6, 12, 24, 36 and 48 months after kraal use) and in surrounding landscape. We also compared Acacia karroo bark nutrient and soil nutrient concentration between nutrient hotspots (24 months after kraal use) and the surrounding landscape. Elephant use of nutrient hotspots was highest at 12 and 24 months after kraaling. The most severely damaged trees were in the 12-, 24- and 36-month-old nutrient hotspots. Acacia karroo bark nutrient concentrations (nitrogen, potassium, calcium, magnesium and iron) were higher in nutrient hotspots than surrounding vegetation, while soil nutrients (nitrogen, phosphorus, calcium and potassium) were higher in nutrient hotspots than surrounding landscape. We concluded that elephants mostly used nutrient hotspots 12 and 24 months after kraaling, while severe tree damage occurred 12, 24 and 36 months after kraal use.

Population Dynamics and Tree Damage of the Invasive Chestnut Gall Wasp, Dryocosmus kuriphilus, in Its Southernmost European Distributional Range

The invasive chestnut gall wasp (CGW), Dryocosmus kuriphilus, the worst pest of chestnut cultivation, has spread worryingly throughout Europe in less than 20 years. Despite the great concern around this pest, little is known about the status in its southernmost distribution in continental Europe. We assessed spatio-temporal patterns in the population dynamics, phenology and tree damage caused by CGW in southern Spain. Likewise, the relationship between these variables and thermal trends was evaluated. We found strong variation in the population dynamics and flight phenology among localities and over time, which were highly influenced by changes in thermal regimes. Specifically, warmer localities and vegetative periods promoted higher population densities, a partial increase in the survival of immature stages, and advanced flight activity. Moreover, tree damage evolved differently over time in each locality, which suggests that local conditions may determine differences in damage evolution. Our findings evidence that great spatio-temporal variability in the CGW populations takes place across invaded areas in its southernmost European distributional range. Although control mechanisms have been introduced, implementation of further control and management measures are critical to cope with this main threat for the chestnut industry and to prevent its spread to nearing chestnut-producing areas.

Tree damage, growth and phenology after a hurricane in a tropical dry forest in Veracruz

As a major disturbance, hurricanes affect growth and phenology of trees. Tree diameters were annually measured for three years, and the phenology of 16 tree species monthly recorded in a seasonally dry tropical forest in Veracruz, Mexico, when on September 2010, Hurricane Karl struck the region. One month later, tree damage was recorded and phenological observations resumed for 12 more months, and diameter measurement for two more years. Tree damage due to the hurricane was high: 10 % were uprooted, 7 % broken and 2 % bent. All trees uprooted died, but some broken or bent trunk trees resprouted (15 % of tagged trees died). Overall, mean diameter growth of trees that survive the hurricane (0.79 cm yr-1) was greater than pre-hurricane growth rate (0.68 cm yr-1). For all the studied species together, leaf fall, leafing, and flowering phenology did not differ between pre- and post-hurricane whereas fruiting was lower for the post-hurricane year. At species level, most species displayed differences in reproductive phenology between pre-hurricane and post-hurricane years. Most species did not flower, lower flowering and fruiting (Calyptranthes schiedeana), or did not fruit (Luehea candida, Maclura tinctoria, Tabebuia chrysantha) the year following the hurricane. In conclusion, due to hurricane damage, tree mortality was high but many trees recovered from damage, and that the hurricane negatively influenced intensity in reproductive phenology, and in turn may alter forest structure, shift species composition, and affect the trophic relationships and functioning of the whole forest community.

Damages to Himalayan White Pine (Pinus wallichiana) by Asiatic Black Bear (Ursus thibetanus) in Kaghan Valley, Pakistan

Tree damage is one of the destructive behaviors of the Asiatic black bear (Ursus thibetanus G. (Baron) Cuvier, 1823), and this type of damage causes great economic loss to the forest. A survey about Himalayan white pine (Pinus wallichiana (A. B) Jacks, 1836) damages was conducted at Kaghan Valley, District Mansehra, Khyber Pakhtunkhwa, Pakistan. Field surveys were carried out within five major sites of Kaghan Valley, including Manshi reserve forest, Kamal Bann reserve forest, Malkandi reserve forest, Noori Bichla reserve forest, and some Guzara forests. Line transects and diameter at breast height (DBH) methods were selected for data collection. Eighteen transects were placed in different sites of the valley. A total of (n = 201) affected trees were observed from eighteen transects, along with a total population of 1081 trees with the encounter rate (ER: 0.657) and the mean DBH is x¯ = 71.97 cm. Among total damages, the most severe (n = 39: 19.4%) were fully damaged with a greater encounter rate. Bark stripping was made during the late winter season and used as foodstuff when natural food is limited in the area. In severe cases, the bear-stripped bark encircles from the entire tree trunk, which results in the drying of trees and, finally, falls. Among all five sites, Manshi reserve forest was greatly affected, where the highest number (n = 76) of tree damage, and (n = 21) the entire diameter of trunks were damaged. People of the study area claimed that the black bear causes great forest damage, as well as crop destruction that leads to high economic loss.