Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it is debated whether mountain endemics mostly originate from local lowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere. Here we investigate the evolutionary routes to endemism by sampling an entire tropical mountain biota on the 4,095-metre-high Mount Kinabalu in Sabah, East Malaysia. We discover that most of its unique biodiversity is younger than the mountain itself (6 million years), and comprises a mix of immigrant pre-adapted lineages and descendants from local lowland ancestors, although substantial shifts from lower to higher vegetation zones in this latter group were rare. These insights could improve forecasts of the likelihood of extinction and 'evolutionary rescue' in montane biodiversity hot spots under climate change scenarios.

Karyati, Ipor IB, Jusoh I, Wasli ME. 2018. Tree stand floristic dynamics in secondary forests of different ages in Sarawak, Malaysia. Biodiversitas 19: 717-723. Succession is a series sequential processes of the development of floristic community which involves changes in community structure, species composition and diversity over time. The information on tree stand floristic dynamics of various stages of succession in secondary forests in Malaysia is currently lacking. This study was conducted to determine tree stand structure, floristic composition, and species diversity in various stages of secondary forest development in the study areas. A total of 997, 1,842, and 834 tree stems with diameter at breast height (DBH) of > 5 cm were recorded in one-hectare-plots of 5, 10, and 20 year old secondary forests, respectively. The ten most common species in 5 and 10 year old of secondary forests consisted mostly of light demanding species. In the 20 year old secondary forest, these species did not exist. Macaranga gigantea was the most dominant tree species in the 5 and 10 year old secondary forests in terms of basal area and volume per hectare. The most common species, based on density, basal area, volume, and Importance Value Index (IVi), in the 20 year old secondary forest was Adinandra dumosa. The diversity and richness indices of the 10 year old secondary forest were the highest among all study sites.

The south-east asian genus Cryptocoryne has been shown to hybridize more frequently than expected. Data are presented on the known naturally occurring hybrids including information on their discovery, naming, and recognition as hybrids. Many artificial hybrids produced over the years indicate that there are only relatively few barriers to crossing. a heterosis effect is prevalent in many encountered Cryptocoryne hybrids. Vegetative propagation is clearly an advantage in the establishment of hybrid populations and also in detecting the hybrids, since inferior hybrids have disappeared naturally. our results on Cryptocoryne also suggest that when the south-east asian floras become as well-known as temperate ones, the number of natural hybrids will be similar to those presently known from temperate regions.

Abstract. Karyati, Ipor IB, Jusoh I, Wasli ME. 2019. Allometric equations to estimate the above-ground biomass of trees in the tropical secondary forests of different ages. Biodiversitas 20: 2427-2436. The allometric equations for trees of secondary forests of different ages in abandoned lands after shifting cultivation are still rarely available. The objective of this study was to develop allometric equations to estimate the above-ground biomass (AGB) of trees (DBH of > 5 cm) in the tropical secondary forest of different ages, namely 5, 10, and 20 years after abandonment. The selected trees in this study represented the dominant and rare species and DBH classes in each study site. The trunk dry biomass and AGB showed strong correlations (adjusted R2= 0.59-0.95) with diameter at breast height (DBH) and height. The leaf and branch dry biomass had weak correlations with height (adjusted R2=0.36-0.50). The developed allometric equations were suitable for trees of secondary forests of different ages, because the selected samples used in the destructive method were based on a field inventory data of forest structure and floristic composition.

This study was to investigate survival, growth and accumulation potential of Acalypha wilkesiana in phytoextraction of heavy metals contaminated soil. Acalypha wilkesiana was tested to evaluate its tolerance and phytoextraction capacity in soils contaminated with metals. It was tested under 10 mL of 100 mg/kg of As, Cr, Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn solution, along 240 days in greenhouse experiment with harvesting period of 60 days interval. Twenty four cuttings from Acalypha wilkesiana were subjected to the same treatment. Plants roots stem and leaves were dry-digested and analyzed using Atomic Absorption Spectrophotometer (AAS). Results show that Fe was the most accumulated metal followed by Cu, Mn, As and Zn with 5002.4, 542.7, 492.2, 396.7 and 308.2 mg/kg, respectively. The concentration of Cr, Ni, and Co was 101.2, 99.09, and 89.63mg/kg respectively. The highest concentration of Pb was 46.44 mg/kg, Cd was not detected by the plant. Bioconcentration Factor (BCF) of metals were above unity in root, stem, and leaf except for Fe which showed a value below the unity, and Pb shows highest BF value of 7.79. The Translocation Factor (TF) of Cr, Co, Fe, Ni, and Pb were higher, while that of As, Cu, Mn, and Zn were below the unity, Co showed the highest value of 15.93. Furthermore, Extraction Coefficient (EC) of Cr, Co, Ni, and Pb were greater than 1, while for remaining metals were lower than unity, the highest EC was observed from Pb with a value 17.21.

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A new hybrid species, Cryptocoryne ×batangkayanensis Ipor, Ørgaard & N. Jacobsen (C. cordata var. grabowskii (Engl.) N. Jacobsen × C. ferruginea Engl. var. ferruginea), from the Batang Kayan basin, Sarawak, Malaysia, is described and illustrated. It is compared with the parent species and an artificial hybrid of the same parentage.