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Dipterocarpaceae is known for its various uses, such as construction wood, veneer, furniture, craft, building green spaces, etc. Research on the distribution and diversity of this species has never been carried out in the green space of the Universitas Sumatera Utara (USU) campus. This type has many benefits as well as the potential to be developed and studied further. Preliminary surveys show species are easy to find and scattered in several locations. The results of this study will be useful as initial data in managing campus green space, information on the use of this type, and a source of data for further research. Therefore, research on the potential family at USU needs to be done and studied further. This study used exploration techniques by visiting all locations in research area. Field findings are described descriptively and cumulatively. There are four species of Dipterocarpacea in the USU green space. It is estimated to be 71 individuals. It consists of 4 species, such as Shorea laevis, Shorea macrophylla, Shorea leprosula and Shorea parvifolia . Shorea parvifolia and Shorea macrophylla are in Least Concern Criteria of IUCN Redlist. On other side, Shorea leprosula is Near Threatened and Shorea laevis is in Vulnerable Criteria of IUCN Redlist.

Shorea is one of the genera in the Dipterocarpacea family with a very large number of species. Shorea tree species have high economic and ecological value. Currently more than 100 species of Shorea are in the endangered category. Taxonomic aspects as well as information on biological characteristics are one of the important bases of species conservation or restoration activities. The University of North Sumatra campus is one of the green open spaces that can be used as an ex-situ conservation location. This study aims to determine the types of trees of the Shorea genus on the North Sumatra University campus and their kinship based on phylogenetic analysis. It is necessary to identify the Shorea species on the USU campus using the current taxonomic method using phylogeny analysis. Sequences of the identified Shorea species were collected from the NCBI (National Center for Biotechnology Information) web, then edited the data and constructed a phylogenetic tree using Meng X.1. In this study found 4 types of Shorea, namely Shorea parvifolia (Meranti Sarang Punai), Shorea laevis (Bangkirai), Shorea macrophylla (Tengkawang Tungkul) and Shorea leprosula. Shorea leprosula species are separated from other Shorea groups. This indicates that Shorea leprosula is closely related to other Shorea. Meanwhile, Shorea macrophylla and Shorea parvifolia are closely related because they are in one cluster, with a boostrap value of 85%.

Shorea is one of the largest genera of the Dipterocarpaceae family that dominates Indonesian forests. This genus has an essential role in meeting the supply of wood, both at home and abroad. There are 194 species of shorea in the tropics. However, there is a high degree of similarity between one species and another, making it difficult to identify it. This study aims to estimate the variation of leaf morphology among 6 species of shorea at PT. Reki using multivariate analysis. Multivariate analysis is a statistical technique for analyzing data with a large number of variables. PCA (Principal component analysis), Biplot, and Manova were the three species of multivariate analysis used in this study. The results of PCA analysis showed that the variables of leaf elongation (PR), lamina length (PL) and leaf width to the base of the leaf (LP) had a strong relationship so that they could be used as a differentiator for the 6 shorea species. Biplot analysis showed that Shorea parvifolia , Shorea acuminata and Shorea leprosula had high similarities. It is also indicated by the leaves of the three species, which are more round in shape. The results of the Manova analysis showed a significant value <0.005, which means that all the variables tested have differences from one another. Shorea acuminata and Shorea leprosula have high similarity, and it is also indicated by the leaves of the three species, which are more round in shape.

1. In a unique phenomenon restricted to the ever wet forests of Southeast Asia, hundreds of species from dozens of plant families reproduce synchronously at irregular, multi-year intervals. The proximate environmental cues that synchronize these general flowering events have not been evaluated systematically because there have been no long-term, high temporal resolution, species-level records from the region. 2. We present 13 years of weekly flowering records for five Shorea species as well as daily temperature and rainfall records from the Pasoh Forest Reserve, Peninsular Malaysia. We constructed models to evaluate hypothesized relationships between flowering and cool temperature, drought, and additive and synergistic effects of cool temperature and drought for each species. Model parameters include periods of time for floral cue accumulation and flower development and temperature and/or rainfall thresholds required for floral initiation. Parameters estimated using flowering observations from 2001 to 2011 were used to forecast flowering for 2011-2014. 3. We show that drought and cool temperatures acting synergistically best explain the timing of flowering events for all Shorea species in the section Mutica and forecast the largest general flowering event accurately. Periods estimated for signal accumulation ranged from 54 to 90 days among species. Periods estimated for flowers to develop ranged between 43 and 96 days and closely followed the interspecific sequence of flowering in the Shorea species. Drought and temperature thresholds also varied among species, with Shorea maxwelliana requiring the most severe drought and Shorea leprosula the lowest temperatures. 4. Synthesis. Our results indicate that cool temperatures and low rainfall occurring on seasonal time-scales of about 2-3 months rather than brief cold snaps or brief droughts best explain general flowering in Shorea species at the Pasoh Forest Reserve. Low rainfall is equally likely in winter (December-February) and summer (July–August) and cool temperatures are most likely in winter at Pasoh, which explains why general flowering events are restricted to spring and fall, with more frequent and stronger flowering in spring. In addition, species-specific sensitivity to environmental cues suggests that future climate change will have differential impacts on the frequency of reproduction, with potential consequences for regeneration of these dominant species of lowland tropical forests.

Form Factor Diameter at Breast Height (DBH) Tree Height (H) Function R2 p Function R2 p Stem over bark FF = 0.2302 + 4.927 × 10−3 DBH − 4.753 × 10−5 DBH2 0.230 <0.001 FF = 0.03069 + 0.02806 H − 0.000604 H2 0.205 <0.001 Stem under bark FF = 0.1366 + 5.404 × 10−3 DBH − 4.573 × 10−5 DBH2 0.327 <0.001 FF = −0.02295 + 0.02437 H − 0.000479 H2 0.250 <0.001 Wood over bark FF = 0.1818 + 8.999 × 10−3 DBH − 7.579 × 10−5 DBH2 0.416 <0.001 FF = −0.0877 + 0.04166 H − 0.000832 H2 0.310 <0.001 Wood under bark FF = 0.1018 + 8.325 × 10−3 DBH − 6.573 × 10−5 DBH2 0.518 <0.001 FF = −0.1058 + 0.03385 H − 0.000633 H2 0.357 <0.001 Reference Table Table 4.Functions for estimating form factors using diameter and height. Form Factor Diameter at Breast Height (DBH) Tree Height (H) Function R2 p Function R2 p Stem over bark FF = 0.2302 + 4.927 × 10-3 DBH - 4.753 × 10-5 DBH2 0.230 <0.001 FF = 0.03069 + 0.02806 H - 0.000604 H2 0.205 <0.001 Stem under bark FF = 0.1366 + 5.404 × 10-3 DBH - 4.573 × 10-5 DBH2 0.327 <0.001 FF = -0.02295 + 0.02437 H - 0.000479 H2 0.250 <0.001 Wood over bark FF = 0.1818 + 8.999 × 10-3 DBH - 7.579 × 10-5 DBH2 0.416 <0.001 FF = -0.0877 + 0.04166 H - 0.000832 H2 0.310 <0.001 Wood under bark FF = 0.1018 + 8.325 × 10-3 DBH - 6.573 × 10-5 DBH2 0.518 <0.001 FF = -0.1058 + 0.03385 H - 0.000633 H2 0.357 <0.001 1. Sony Baral1,*, Mathias Neumann2, Bijendra Basnyat3, Kalyan Gauli1, Sishir Gautam4, Shes Kanta Bhandari5 and Harald Vacik6 1The Resource Nepal, Kathmandu 44600, Nepal 2Faculty of Science Engineering and Technology, Swinburne University of Technology, Melbourne 3136, Australia 3Institute of Forestry, Tribhuvan University, Kathmandu 44613, Nepal 4Canadian Forest Service, Natural Resources Canada (Current Address), 506 Burnside Rd W, Victoria, BC V8Z 1M5, Canada 5Institute of Forestry, Tribhuvan University, Pokhara 33700, Nepal 6Institute of Silviculture, University of Natural Resources and Life Sciences, 1190 Vienna, Austria *Author to whom correspondence should be addressed.

Key message This study demonstrated that the cambial activities of three selected Shorea species with different stem diameters growing in a tropical rainforest in Malaysia responded differently to climatic factors. We investigated the cambial activities in Shorea leprosula, Shorea acuminata , and Shorea parvifolia trees with different stem diameters at breast height growing in a natural lowland dipterocarp rainforest in Malaysia. We collected and analyzed samples from the main trunks of selected trees in monthly intervals from March 2013 to April 2014. The cambium of the three Shorea species showed periods of active and less active growth in the humid forest. Selected trees with different stem diameters of the same and different species showed variation in rhythms of cambial activity (changes in the numbers of cambial and enlarging cell layers) at site with similar growing conditions. Monthly mean relative humidity and monthly mean vapour pressure deficit were important factors influencing the number of cambial cells of S. acuminata with larger stem diameter, and those of S. parvifolia with different stem diameters. Active cambium were detected in months with high relative humidity and low vapour pressure deficit in those trees. Total monthly precipitation had significant positive correlation with the cambial cells activities of S. parvifolia with different stem diameters, but no correlation with those of the other two species. The cambium of S. leprosula with smaller and larger stem diameters were found active throughout the year. We concluded that the three Shorea species examined with different stem diameters have different growth strategies and thus react differently to climatic factors.

Shorea sp. (meranti) is a wood-producing tree from Indonesia that has many benefits in world trade. Meranti cultivation is carried out to rehabilitate and develop plantation forests. However, meranti cultivation is susceptible to various pest attacks, including Calliteara cerigoides . This study aimed to determine the food preferences of C. cerigoides and to analyze the phytochemical compounds in meranti leaves. Pest food preferences were tested by testing three meranti leaf species on C. cerigoides larvae. Three species of meranti were Shorea selanica, S. pinanga , and Shorea sp. Phytochemical tests were carried out by identifying seven secondary metabolic compounds in meranti leaves. The results showed that C. cerigoides larvae preferred S. selanica leaves and survived until the seventh instar. The content of tannin and hydroquinone phenolic compounds in the leaves of S. pinanga is thought to be an obstacle in the pest’s food preference, causing the larvae to die in the third instar. The content of alkaloid and flavonoid compounds in the leaves of Shorea sp. was suspected to be the cause of the larvae not surviving until the instar phase and only until the fourth instar. Morphological factors and the content of chemical compounds in meranti leaves affect the eating preferences of larvae.

Key messageXylem maturation depends on cambial age rather than diameter growth inShorea macrophyllaby the model selections for radial variations in cell length, wood fiber traits, and basic density.Radial variations in anatomical characteristics and wood properties were investigated in 23-year-old Shorea macrophylla (engkabang) trees planted in Sarawak, Malaysia. The effects of radial growth rates on anatomical characteristics and wood properties and the manner of xylem maturation were determined based on selected mixed-effects models. The best models of radial variation were fitted by linear functions for wood fiber length, wood fiber wall thickness, basic density, and compressive strength. Logarithmic functions were applied for vessel element length and vessel frequency, and quadratic functions were applied for vessel diameter and wood fiber diameter. Vessel diameter and wood fiber length were affected by radial growth rates although these effects on the other properties were minimal. In the fixed part of the models, the results showed small mean absolute error values of radial variation in relation to the distance from the pith according to vessel frequency and vessel diameter. In contrast, in relation to the estimated cambial age, smaller mean absolute error values were obtained for cell length, wood fiber traits, and basic density, suggesting that all properties varied from pith to bark in relation to the cambial age, except for vessel traits. Thus, in S. macrophylla, xylem maturation in cell length, wood fiber traits, and basic density were due to cambial age rather than diameter growth, but xylem maturation in vessel traits depended on diameter growth.

Tree seedlings in tropical rain forests are subject to both damage from natural enemies and intense interspecific competition. This leads to a trade-off in investment between defense and growth, and it is likely that tree species specialized to particular habitats tailor this balance to correspond with local resource availability. It has also been suggested that differential herbivore impacts among tree species may drive habitat segregation, favoring species adapted to particular resource conditions. In order to test these predictions, a reciprocal transplant experiment in Sabah, Malaysia, was established with seedlings of five species of Dipterocarpaceae. These were specialized to either alluvial (Hopea nervosa, Parashorea tomentella) or sandstone soils (Shorea multiflora, H. beccariana), or were locally absent (S. fallax). A total of 3000 seedlings were planted in paired gap and understory plots in five sites on alluvial and sandstone soils. Half of all seedlings were fertilized. Seedling growth and mortality were recorded in regular samples over 3.5 years, and rates of insect herbivore damage were estimated from censuses of foliar tissue loss on marked mature leaves and available young leaves. Greater herbivory rates on mature leaves had no measurable effects on seedling growth but were associated with a significantly increased likelihood of mortality during the following year. In contrast, new-leaf herbivory rates correlated with neither growth nor mortality. There were no indications of differential impacts of herbivory among the five species, nor between experimental treatments. Herbivory was not shown to influence segregation of species between soil types, although it may contribute toward differential survival among light habitats. Natural rates of damage were substantially lower than have been shown to influence tree seedling growth and mortality in previous manipulative studies.

Although cutting is a useful method for vegetative propagation and tree breeding, there is a difference in rooting ability between tree species and even between node positions within a species. A large number of F¹ hybrids of Shorea (Shorea curtisii × S. leprosula) (Dipterocarpaceae) have recently been found in Singapore. Given that some of the hybrid traits appear to have higher physiological performances than those of their parent species, understanding the rooting ability of the leafy-stem cuttings of F¹ hybrids may contribute to performance improvement in dipterocarp trees. In this study, we compared the rooting abilities of cuttings taken from seedlings of F¹ hybrids and their parent species at different node positions. The cuttings of F¹ hybrids showed rooting ability with small internode differences, and the rooting rate (32.2%) was almost intermediate between those of S. curtisii (42.0%) and S. leprosula (21.0%). The rooting rates of hybrids and parents fell into the middle range of previously reported values for 21 closely related Shorea species. Overall, the rooting ability of F¹ hybrids is comparable with that of their parent species and/or other Shorea species in the red meranti group. Thus, F¹ hybrids could be mass propagated through cuttings.