[en] Blue gum chalcid (BGC) Leptocybe invasa is a gall-forming wasp that belongs to the insect order Hymenoptera, family Eulophidae. It attacks a wide range of Eucalyptus species mostly between the seedling stage and five years of age. BGC causes damage to eucalyptus by forming bump-shaped galls on the leaf midribs, petioles and stems.Twisted and knobbed leaves manifest severe infestation. The aim of this study was to establish the spatial distribution of BGC and extent of host plant damage in Eucalyptus woodlots in Western Kenya. The study was carried out in six permanent sampling plots in Eucalyptus woodlots in Busia, Bungoma, Kakamega and Nyando. Trees were assessed for crown damage by estimating and classifying the density of galls on the leaves into four levels of infestation: low (greater than 50% of foliage canopy with galls and no twisted or knobbed leaves), moderate (greater than 50% of foliage with galls and less than 50% of the leaves twisted and knobbed), high (greater than 50% of the leaves twisted and knobbed, galls on the twigs and some twigs deformed and severe (greater than 50% of the twigs deformed and regeneration foliage observed). An evaluation of the pests' infestation and the extent of host plant damage indicated that, 4% of the trees and severe infestation; 5% high; 20% moderate and 70% low. Approximately 1% of trees died as a result of loss of foliage attributable to severe infestation. Other observations from the study were that the severity of BGC infestation tended to decline as trees grew older and BGC infestation retarded tree growth

[en] Blue Gum chalcid is a gall-forming wasp, which causes an extensive damage to Eucalyptus. It attacks mostly seedlings and field saplings. It causes damage on it's host by forming massive typical bump-shaped galls on trees canopy, specifically on the leaf midribs, petioles and stems of new growths. The pest was first reported in Kenya and Uganda in 2002 attacking the three major commercially grown Eucalyptus species; Eucalyptus grandis, E. camaldulennsis, E. saligna in East Africa. Eucalyptus is fast growing and widely planted in both plantations and farmers' woodlots. It is important for both industrial and domestic use. It is a major source of income generation for rural poor families. The objective of this study was to determine the spatial distribution, incidence and severity patterns of L. invasa and possible relationship to environment and biophysical factors in East Africa. Over 312 randomly selected stands were assessed for BGC incidence to it's distribution. In each identified stand 60 trees were selected from 3 randomly established plots of 20 trees each and BGC damage/incidence assessed on a 4-point scale. This was to determine the incidence and severity patterns. ANOVA using generalized linear procedures, regression analysis and correlation were done to determine the relationship between the percentage incidence of L. invasa infestation against altitude, age interval, agro-ecological zones and topography. There was widespread of pest in all the districts sampled. There was significant difference (p<0.05) on BGC incidence on agro-ecological zones. There was no significant difference (p>0.05) on L. invasa incidence among the three species. The study recommends that. further studies on damage and L. invasa population dynamics relationship to environment and biophysical factors should be conducted

[en] Highlights: • MIBK/H₂O pretreatment with biphasic system was applied to treat Eucalyptus. • Treatment condition had obvious effect on yield of furfural and glucose conversion. • Optimum condition was obtained (V_MIBK:V_H2O = 5:5, 150 °C, 60 min, 0.3 M HCl). • MIBK/H₂O pretreatment was effective for production of clean energy and biochemical. - Abstract: Forest wood biomass can be a sustainable and cost-effective feedstock for the biorefinery industries, but the rigid and compact structure of plant cell is a major barrier for production of clean energy and biochemical. In this case, the MIBK/H₂O pretreatment with biphasic system was applied to treat Eucalyptus and then systematically evaluated pretreatment conditions (e.g., MIBK/H₂O ratio, reaction temperature and time, NaCl concentration, and HCl dosage) on the effect of furfural yield. The resulting solid fraction obtained from the optimum pretreatment condition for furfural yield was to produce fermentable glucose by enzymatic hydrolysis. Study on enzymatic hydrolysis of the raw material and resulting solid fraction obtained by single aqueous system was also contrastively investigated. The furfural yield was 65.9% and the recovery of residue was 46.9% under an optimal reaction condition (V_MIBK:V_H2O = 5:5, 150 °C, 60 min, 0.3 M HCl). Meanwhile, the yield of glucose of cellulose was improved after the pretreatments with different systems and a maximum value was up to 60.2% by the MIBK/H₂O pretreatment. The effective fermentable glucose production was mainly affected by the significant removal of hemicelluloses, change of CrI, and destruction of surface morphology of Eucalyptus. The MIBK/H₂O pretreatment can be considered as a potential approach for efficient conversion of Eucalyptus to clean energy and biochemicals.

[en] Published in summary form only

[en] Aim of the study: This study was conducted to support fire and forest management planning in eucalypt plantations based on economic, ecological and fire prevention criteria, with a focus on strategic prioritisation of fuel treatments over time. The central objective was to strategically locate fuel treatments to minimise losses from wildfire while meeting budget constraints and demands for wood supply for the pulp industry and conserving carbon. Area of study: The study area was located in Serra do Socorro (Torres Vedras, Portugal, covering ~1449 ha) of predominantly Eucalyptus globulus Labill forests managedcultivated for pulpwood by The Navigator Company. Material and methods: At each of four temporal stages (2015-2018-2021-2024) we simulated: (1) surface and canopy fuels, timber volume (m3 ha-1) and carbon storage (Mg ha-1); (2) fire behaviour characteristics, i.e. rate of spread (m min-1), and flame length (m), with FlamMap fire modelling software; (3) optimal treatment locations as determined by the Landscape Treatment Designer (LTD). Main results: The higher pressure of fire behaviour in the earlier stages of the study period triggered most of the spatial fuel treatments within eucalypt plantations in a juvenile stage. At later stages fuel treatments also included shrublands areas. The results were consistent with observations and simulation results that show high fire hazard in juvenile eucalypt stands. Research highlights: Forest management planning in commercial eucalypt plantations can potentially accomplish multiple objectives such as augmenting profits and sustaining ecological assets while reducing wildfire risk at landscape scale. However, limitations of simulation models including FlamMap and LTD are important to recognise in studies of long term wildfire management strategies. (Author)

No abstract available

[en] Aim of study: The study aimed to characterise variation in structural attributes of vegetation in relation to variations in topographic position using LIDAR data over landscapes. Area of study: The study was conducted in open canopy eucalypt-dominated forest (Richmond Range National Park-RRNP) and closed canopy subtropical rainforest (Border Ranges National Park-BRNP) in north-eastern New South Wales, Australia. Material and Methods: one metre resolution digital canopy height model (CHM) was extracted from the LIDAR data and used to estimate maximum overstorey height and crown area. LIDAR fractional cover representing the photosynthetic and non-photosynthetic component of canopy was calculated using LIDAR points aggregated into 50 m spatial bins. Potential solar insolation, Topographic Wetness Index (TWI), slope and the elevation were processed using LIDAR derived digital elevation models. Main results: No relationship was found between maximum overstorey height and insolation gradient in the BRNP. Maximum overstorey height decreased with increasing insolation in the RRNP (R2 0.45). Maximum overstorey height increased with increasing TWI in the RRNP. Average crown area decreased with increasing insolation in both study areas. LIDAR fractional cover decreased with increasing insolation (R2 0.54), and increased with increasing TWI (R2 0.57) in the RRNP. Research highlights: The characterization of structural parameters of vegetation in relation to the variation of the topography was possible in eucalyptus dominated open canopy forest. No reportable difference in variation of structural elements of vegetation was detected with topographic variation of subtropical rainforest. (Author)

[en] Farmers in developing countries are one of the world's largest and most efficient producers of sequestered carbon. However, measuring, monitoring and verifying how much carbon trees in smallholder farms are removing from the atmosphere has remained a great challenge in developing nations. Devising a reliable way for measuring carbon associated with trees in agricultural landscapes is essential for helping smallholder farmers benefit from emerging carbon markets. This study aimed to develop biomass equations specific to dominant eucalyptus species found in agricultural landscapes in Western Kenya. Allometric relationships were developed by regressing diameter at breast height (DBH) alone or DBH in combination with height, wood density or crown area against the biomass of 48 trees destructively sampled from a 100 km² site. DBH alone was a significant predictor variable and estimated aboveground biomass (AGB) with over 95% accuracy. The stems, branches and leaves formed up to 74, 22 and 4% of AGB, respectively, while belowground biomass (BGB) of the harvested trees accounted for 21% of the total tree biomass, yielding an overall root-to-shoot ratio (RS) of 0.27, which varied across tree size. Total tree biomass held in live Eucalyptus trees was estimated to be 24.4 ± 0.01 Mg ha⁻¹, equivalent to 11.7 ± 0.01 Mg of carbon per hectare. The equations presented provide useful tools for estimating tree carbon stocks of Eucalyptus in agricultural landscapes for bio-energy and carbon accounting. These equations can be applied to Eucalyptus in most agricultural systems with similar agro-ecological settings where tree growth parameters would fall within ranges comparable to the sampled population. -- Highlights: ► Equation with DBH alone estimated aboveground biomass with about 95% accuracy. ► Local generic equations overestimated above- and below-ground biomass by 10 and 48%. ► Height, wood density and crown area data did not improve model accuracy. ► Stems, roots, branches and leaves formed 58, 21, 18 and 3% of total tree biomass

[en] The concentrations of heavy metals viz., Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in leaves of two tree species, Melia azedarach and Eucalyptus citriodora (Safeda) from different sampling sites at urban areas in Quetta city , were measured. Correlation between elements and the use of tree leaves as indicators of environmental pollution was investigated. The results show that the higher concentrations of heavy metals in Eucalyptus leaves of the areas of the Hudda, Barori and Mashraqi by Pass and in the areas with dense transportation activities are in function. So this preliminary study presents scientific basis to establish the applicability of the tree leaves as bio-monitoring tool for the rapid evaluation of the pollution status in the Quetta city by analyzing heavy metals concentration in the tree leaves. (author)

[en] Biochar is partially oxidized residues from substrates of biological origin. Due to their binding properties with various organic and inorganic pollutants, these materials are widely studied for pollutant abatement both in field studies and laboratory investigations. Though large quantity of information is available on the use of biochar of various origin for heavy metals, studies pertaining to their use in radionuclide sorption are scarce in literature. Here we are reporting the sorption characteristics of U(VI) and Am(III) on to eucalyptus biochar as a function of various operating parameters such as solution pH, initial metal ion concentration, contact time and ionic strength of the medium. Overall the present studies shows that eucalyptus biochar is a suitable sorbent for the sorption of heavy radionuclides from aqueous solutions