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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.

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 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.

Large‐scale conversion of tropical forests into oil palm monocultures has led to dramatic losses of biodiversity and ecosystem functions. While ecological restoration is urgently needed in many oil palm landscapes, there is a lack of scientific knowledge of sustainable management strategies. We established experimental tree islands of varying sizes (25 m2 to 1,600 m2) and diversity levels (1, 2, 3 and 6 species) in an oil palm plantation in Sumatra, Indonesia. Six native multi‐purpose tree species including Archidendron pauciflorum (Jengkol), Durio zibethinus (Durian), Parkia speciosa (Petai), Shorea leprosula (Meranti), Peronema canescens (Sungkai) and Dyera polyphylla (Jelutung) were planted between living and felled oil palms. Here, we analyse the controlling factors of tree growth and survival during the first 4 years at the level of local neighbourhood and tree island. We found a significant effect of diversity levels on tree productivity, that is, basal area was higher in multi‐species than in single‐species tree islands. This overyielding was attributed to enhanced tree growth, while mortality had no effect. In the local neighbourhood, tree species richness had a positive effect on tree growth during the first year only, indicating that selection and dominance of well‐performing species at high level of diversity are most likely driving overyielding. Trees grew better away from living oil palms, suggesting tree‐palm competition. Proximity to felled oil palms increased growth especially during the first years, during which the planted trees might have benefited from the additional available space and resources. Despite positive edge effects from the conventional oil palm management in the surrounding, tree island size had an overall positive effect on tree growth. Synthesis and applications. We planted native trees in an oil palm landscape following a tree island pattern. The establishment success differed widely among the six planted species. The selection of particular species is a decisive factor to foster a positive relationship between diversity and tree growth. Planting larger tree islands (e.g. 1,600 square metres) is a better option to enhance tree growth, but tree‐palm competition implies a trade‐off between tree growth and palm oil production in the tree islands. Ringkasan Konversi ekosistem hutan tropis secara luas menjadi kebun kelapa sawit monokultur mengakibatkan kehilangan keanekaragaman hayati dan fungsi ekosistem secara dramatis. Sehingga restorasi ekologi sangat diperlukan pada berbagai lanskap kelapa sawit, namun pengetahuan empiris tentang strategi pengelolaan kelapa sawit yang lestari masih sangat terbatas. Percobaan penanaman pohon dalam pola pulau‐pulau dengan berbagai ukuran petak (25 m2 sampai 1,600 m2) dan berbagai tingkat keragaman spesies pohon (1,2,3, dan 6 spesies) dilakukan di kebun sawit di Sumatera, Indonesia. Enam spesies pohon multiguna dan asli Sumatera yaitu Jengkol (Archidendron pauciflorum), Durian (Durio zibethinus), Petai (Parkia speciosa), Meranti (Shorea leprosula), Sungkai (Peronema canescens), dan Jelutung rawa (Dyera polyphylla) ditanam diantara pohon sawit. Penebangan beberapa pohon kelapa sawit dilakukan untuk memberi ruang bagi pohon yang ditanam. Data yang dianalisis berupa faktor‐faktor yang mempengaruhi pertumbuhan dan persentase hidup pohon selama empat tahun. Hasil penelitian menunjukan bahwa keragaman species dalam petak berpengaruh nyata terhadap produktifitas pohon. Basal area pohon pada petak dengan keragaman spesies yang tinggi berbeda nyata dengan basal area pohon pada petak satu spesies. Perbedaan tersebut disebabkan oleh pertumbuhan pohon, sedangkan kematian pohon tidak memberikan pengaruh nyata. Keragaman species pohon juga memberikan pengaruh positif pada pertumbuhan pohon tetapi pengaruh tersebut hanya terjadi pada tahun pertama saja. Hal ini mengindikasikan bahwa seleksi dan dominansi pohon pada tingkat keragaman spesies yang tinggi menjadi faktor penyebab dari perbedaan tersebut. Pohon yang tumbuh jauh dari kelapa sawit cenderung untuk tumbuh lebih baik dibandingkan dengan pohon yang tumbuh dekat dengan kelapa sawit. Hal ini menunjukan adanya kompetisi antara kelapa sawit dengan pohon. Sementara itu, pohon yang ditanam berdekatan dengan kelapa sawit yang ditebang memiliki pertumbuhan yang lebih terutama pada tahun pertama. Hal ini dapat disebabkan oleh ketersedian ruang tumbuh dan unsur hara hasil pelapukan batang kelapa sawit. Meskipun terdapat efek tepi positif dari pengelolaan kelapa sawit konvensional di sekitarnya, ukuran pulau pohon memiliki efek positif secara keseluruhan pada pertumbuhan pohon. Sintesa dan penerapan. Penanaman dalam pola pulau‐pulau pohon di perkebunan sawit dapat dilakukan melalui pencampuran tanaman kelapa sawit dengan spesies pohon asli. Keberhasilan penanaman sangat berbeda‐beda diantara spesies pohon. Pemilihan spesies pohon menjadi faktor penentu hubungan positif antara pertumbuhan pohon dengan keanekaragaman jenis. Penanaman pohon dalam pulau yang lebih luas (misalnya > 1,600 m2) dapat dilakukan untuk meningkatkan pertumbuhan pohon, namun kompetisi pohon dan sawit dapat berimplikasi terhadap pertukaran (trade‐off) pertumbuhan pohon dengan produksi buah sawit. We planted native trees in an oil palm landscape following a tree island pattern. The establishment success differed widely among the six planted species. The selection of particular species is a decisive factor to foster a positive relationship between diversity and tree growth. Planting larger tree islands (e.g. 1,600 square metres) is a better option to enhance tree growth, but tree‐palm competition implies a trade‐off between tree growth and palm oil production in the tree islands.

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%.

This research aims to analyze the growth and identify p eat soil chemical properties under the Shorea leprosula Miq.stand. This research was carried out at the Palangka Raya University Seedling Seed Orchard (SSO) which is located in the Green Campus Area of Palangka Raya University. The sampling method in the field uses a purposive sampling method to take the first tree sample on each route and continue with Systematic Sampling, by measuring 10 tree samples on each route, the total number of trees measured on all routes are 300 trees. Meanwhile, to identify soil by taking soil samples in 2 plots, For soil chemical characterization analysis. Based on research results S. leprosula growth annual increment in diameter, height, and volume were 0.99 cm. year-1 66.96 cm year-1 0.0023 m3. year-1 respectively. Soil fertility criteria under the Meranti Merah stand, it can be seen that the only P content is very high in the soil, while the soil pH has very strong acid and several other elements have low and shallow criteria levels.

Shorea leprosula Miq. is one of Indonesia’s native red meranti species with a higher growth increment than other meranti species. Gunung Dahu Research Forest is a rehabilitated hilly landscape planted with various species of Dipterocarpaceae. This study aims to analyze the growth performance of 24 years old of S. leprosula stands in various slope classes of line planting technique at Gunung Dahu Research Forest. Growth analysis of S. leprosula was carried out by measuring the stem diameter, total tree height, basal area, diameter increment, height increment, and Leaf Area Index (LAI). Slopes were divided into three classes: mild/gentle (15-25%), steep (>25-45%) and very steep (>45%). The results showed that slope class significantly affected height growth and the canopy cover of S. leprosula , but it did not affect the diameter growth. A very steep slope provided the best growth to diameter (average diameter 30.07 cm; MAI 1.25 cm/year) and height (average height 23.7 m; MAI 0.99 m year −1 ). Furthermore, a linear relationship was formed between the crown cover and slope class in which denser crowns were established in response to a steeper slope (LAI 3.4). Thus, planting S. leprosula as a rehabilitation effort in steep slope landscape delivers beneficial as they showed better growth performance.

Shorea leprosula Miq is a species from Dipterocarp family with high economic value but has complex problems in seeds availability and storage. S. leprosula stand in Gunung Dahu Research Forest (GDRF), Bogor-West Java has been flowering for several times that makes these stand to have potential to be developed as seed stand. This research was aimed to assess the potential of Gunung Dahu Research Forest as source-identified seed stand for S. leprosula. Assessment was carried outin plot number 1, 2, 5, 7 and 21A by developing a scoring technique to several criteria, those were: total amount of seed trees, stand's quality, flowering and fruits quality, stand's health, trees parentage, accessibility, and stand's security. Only those of plots having 94 points or above would be accepted as seed stand and that designated plot number 2, 5, and 21A with total score 131; 131.5; and 96.5 points accepted as seed stands while plot number 1 and 7 were failed to fulfil the criteria. Among those of accepted plots, plot number 5 has higher potential as seed stand because it has fewer disturbances than plot number 2.

Shorea leprosula is a promising species to be used for reforestation and offers opportunities for enhancing carbon sink. The study was carried out in Gunung Dahu Forest Research, Indonesia. This paper reports growth performance, production potential and biomass accumulation of 12-yr-old Shorea leprosula by measuring the tree growth attributes. Based on the basal area, destructive samplings of 18 representative trees were done. The results showed that diameter and height growth and the proportion of canopy were found to have a positive relationship with the spacing regime. Growth performance in monoculture planted-system showed better results than other in mix planted-system for all spacing regimes. The regression models related to growth parameters, such as diameter (D) and height (H) to stem volume and biomass were constructed, then used to estimate stem and biomass accumulation. Production potential are 154.85, 136.97, 38.95 and 83.22, 72.99, 48.41 m 3 /ha for monoculture planted of 2 x 2, 3 x 3, 5 x 5 and mix planted of 2 x 2, 3 x 3 and 5 x 5 m spacing, respectively and their total biomass accumulations are 89.89, 76.78, 24.27 and 49.74, 43.95, 30.05 Ton/ha. The figure for production potential and biomass accumulation indicated that their quantifications can be estimated using D and D-H.

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.