The disturbance of mangrove forests could affect climate regulation, hydrological cycles, biodiversity, and many other unique ecological functions and services. Proper biomass estimation and carbon storage potential are needed to improve forest reference on biomass accumulation. The establishment of a site-specific allometric equation is crucial to avert destructive sampling in future biomass estimation. This study aimed to develop a site-specific allometric equation for biomass estimation of a mix-mature mangrove forest at Sungai Pulai Forest Reserve, Johor. A stratified line transect was set up and a total of 1000 standing trees encompassing seven mangrove tree species were inventoried. Destructive sampling was conducted using the selective random sampling method on 15 standing trees. Five allometric equations were derived by using diameter at breast height (D), stem height (H), and wood density (ρ) which were then compared to the common equation. Simulations of each allometric equation regarding species were performed on 1000 standing trees. Results showed that the single variable (D) equation provided an accurate estimation, which was slightly improved when incorporated with the H variable. Both D and H variables, however, gave inconsistent results for large-scale data and imbalance of sampled species. Meanwhile, the best fit either for small-scale or large-scale data, as well as for imbalanced sample species was achieved following the inclusion of the ρ variable when developing the equation. Hence, excluding the H variable while including the ρ variable should be considered as an important determinant in mixed mangrove species and uneven-aged stand for aboveground biomass estimation. This valuation can both improve and influence decision-making in forest development and conservation.

Leaf traits, which vary across different climatic conditions, can reveal evolutionary changes within a species made to adapt to the environment. Leaf traits play major roles in a plant functions under varying climatic conditions. To examine adaptive modes and mechanisms applied by plants in different climates, we analyzed leaf morphology and anatomical structures in Quercus brantii in the Zagros forests, Western Iran. The plants adapted to the environmental differences with increased dry matter content in a Mediterranean climate, and increasing leaf length, specific leaf area, stomata length (SL), stomata width, stomatal density (SD), stomatal pore index (SPI), trichome length, and width in a sub-humid climate; trichome density was increased in a semi-arid climate. There were strong, positive correlations between SPI with SL and SD. Correlations for other leaf traits were weakly significant. Such morphological and anatomical plasticity probably leads to lower transpiration rates, control of internal temperature and water status, and improved photosynthetic capability under stressing conditions. These findings provide new insights into the adaptive strategies of plants to environmental changes at the morphological and anatomical levels.

The establishment of an Acacia mangium plantation often alters physicochemical characteristics and nutrient concentrations of soils. We aimed to evaluate the invasive potential of A. mangium forest on the soil in Ayer Hitam Forest Reserve, Peninsular, Malaysia. To achieve the mentioned target, four different regions, namely, the open ground region (OG), Acacia mangium region (AM), transition region (TZ), and native forest region (NF), were selected and each of the regions was divided into six plots. Composite samples were randomly taken from subplots at 0–15 cm depth (topsoil) and 15–30 cm depth (subsoil). Some physicochemical properties such as soil moisture and texture, textural classification, bulk density and particle density, pH, electric conductivity (EC), exchangeable bases (EB) (Ca, Mg and K), cation exchange capacity (CEC), organic matter (OM), total nitrogen (TN), and available phosphorous (Av. P) were analyzed. The results of our study showed that the soil of the AM region, which was clay loam, contained clay (51%), silt (32%), and sand (16%). The chemical analysis of topsoil showed significant differences in terms of OM%, exchangeable- Ca, Mg, K (molc kg⁻¹), N (%), gravitational water content (GWC), and Avail. P between all four regions. Additionally, the highest pH and OM of topsoil were seen in the AM region with 4.5% and 4.33%, respectively. In the subsoil, there were significant differences (p ≤ 0.01) in terms of EC (ds/m), OM (%), Exchangeable- Ca, Mg and K (cmolc kg⁻¹), GWC, available phosphorus, and N (%) between all four regions. The highest GWC, N (%), and Ca (cmolc kg⁻¹) were observed in the AM region with 16.00, 0.14%, and 0.64 cmolc kg⁻¹, respectively. These results showed that A. mangium changed some soil characteristics due to its invasion potential. In summary, A. mangium showed high adaptability on degraded forest land and high ability to accumulate the soil physicochemical properties to enhance its growth.

Tree decline due to climate change results in physiological weaknesses, attacks by harmful pests and pathogens and threats to forest ecosystem stability. In the work described here, the effects of drought on wood density, tree ring width and variations in vessel morphology are investigated in Persian oak (Quercus brantii) in the forest of the Zagros Mountains, Ilam Province, western Iran. Discs are cut from trunks of declined and healthy trees and woodblocks are cut radially from the sapwood near the bark, at a mid-point between the vascular cambium and the pith (middle) and from wood near the pith. Observations are made on transverse sections from the blocks using microscopy. In trees with decline symptoms, wood density is greater than in healthy trees. Furthermore, declining trees have the narrowest ring width, reduced vessel diameter and area and the highest numbers of vessels and tylose in pith towards the bark. It is concluded that changes in anatomical features are associated with the weakening of trees and are components of declining tree health.