Endemic Tree Species Research Articles

Tropical cloud forest plant endemism persistence within crop-fallow systems in a Mesoamerican hotspot area

Tropical montane cloud forests (TMCF) under natural disturbances have shown high endemism in early successional vegetation. However, little is known about anthropogenic disturbances and plant endemism in TMCF under ancient agricultural management. In this sense, I assessed the number of species, abundance, and frequency of endemic vascular plants in temporary plots of cultivated and young fallow areas from two maize-based systems: milpa shifting cultivation (MS) and semi-permanent cropping (SP) in Oaxaca, Mexico. Overall, both agricultural stages and systems harbored endemic species, seven in total, but most of such species were found in the fallow stage than in the cropping stage, and in the MS system than in the SP system. A single Asteraceae herbaceous endemic species (Melampodium mimulifolium) was commonly recorded in cultivated fields, but almost exclusive to the SP cropping system. Seven species were recorded in fallows, where the narrow-range endemic tree species Clethra integerrima (Clethraceae) was the most abundant and frequent, but almost exclusive to the MS cropping system. In more permanent and intensified agricultural systems within biodiversity hotspots, only ruderal endemic herbaceous species can persist. In contrast, in low intensity managed agricultural systems, like ancient agroforestry, not only can endemic tree species prosper, but also restricted endemic trees can be found. Indigenous agricultural systems in biodiversity hotspots should not be seen as a threat, but rather as complementary areas for endemism conservation.

Water relations and non-structural carbohydrate responses to the combined effects of defoliation and progressive drought in a dioecious tree

Increases in drought frequency and insect defoliation are emerging threats that typically affect the plantation production of Populus yunnanensis, which is an endemic dioecious tree species in China. Nevertheless, it is difficult to predict which sex of P. yunnanensis will be more affected by the combined effects of water limitations and defoliation. In this study, we examined the combined effects of progressive drought and defoliation on water relations, growth, gas exchange and leaf carbohydrate reserves in P. yunnanensis females and males to test whether defoliation alters the effects of drought and and how this response varies between genders. The experimental design included two watering regimes (well-watered and drought-stressed) and two levels of defoliation (leaves untouched and 60% defoliated). Defoliation exacerbated drought stress in females by decreasing photosynthesis, dry mass accumulation and leaf non-structural carbohydrate (NSC) concentration. In contrast, the total biomass of males grown under drought combined with defoliation was not significantly altered when compared to those grown under drought alone. These results suggest that defoliation does not aggravate the drought effects on males. The males presented a high capacity to maintain foliar water status through stomatal control under drought conditions irrespective of defoliation treatment. The conservative water use strategy in males resulted in a gradual reduction in leaf water potential, gas exchange rates and NSC. Our data showed that the different responses of the females and males to drought and defoliation were influenced by plant water status and consequent effects on changes in carbon assimilation and leaf non-structural carbohydrate reserves.

Individual tree diameter growth modeling system for Dalat pine (Pinus dalatensis Ferré) of the upland mixed tropical forests

Pinus dalatensis Ferré (Dalat pine, or five-needle pine, locally) is an endemic large tree species of Vietnam that has both high timber and non-timber values. It is also a rare tree species listed in the Red List of the International Union for Conservation of Nature (IUCN). The objective of this study was to develop an individual tree diameter growth modeling system to facilitate the sustainable management and conservation of this species. We used Haglöf Sweden ® increment borers to collect tree ring samples from a total of 56 trees resulting in a dataset of 4566 diameter at breast height (dbh, cm) measurements at age (t, year) and obtained the associated ecological environmental factors in three different sites in the Central Highlands, Vietnam. A subset of this dataset (n = 1264) also had the climate data collected over the period of past 32–38 years (from 1980 to 2011 and from 1979 to 2016). Weighted mixed-effects models were used to model Dalat pine trees growth and account for autocorrelation and heteroscedasticity of the dbh measurements. Cross validation over 200 realizations were used to select the best equation form of dbh growth and incorporate the environmental effects and climatic factors that help improve reliability of the models. Under the mixed-effects modeling paradigm, the Mitscherlich equation fitted with random effects of ecological environmental factors (eco-subregions and altitude) and climatic factors (temperature, humidity, and temperature in dry and in rainy seasons) produced the best results. Whereas, under the fixed-effect modeling paradigm, the models that used the exponential function of environmental or climatic factors as the modifiers of an average diameter growth performed the best (Bias = −5.9% and RMSE = 10.0 cm). The models developed in this study will be useful for forecasting growth and for silvicultural planning under shifting environment and climate and are expected to contribute to the sustainable management of this endemic species.

Sığla yağının sinnamik asit ve alkollerinden elde edilen türevler

Sığla ağacı (Liquidambar orientalis Miller) Türkiye’de yetişen endemik bir ağaç türüdür. Muğla bölgesinde (Köyceğiz, Fethiye) yetişen ağaç dünyada 4 türe sahiptir. Sığla ağacı görünüş olarak çınara benzer fakat yaprakları çınar yaprağından daha küçüktür. Ağaçlar uzun ömürlü (200-300 yıl) ve 25-30 metre uzunluğa sahiptirler. Ağacın çoğalması, tohum, kök ve kütük sürgünlerden olur. Ormanların kesilmesi ve aşırı üretim gibi sebeplerden günümüzde sığla ormanlarının miktarı çok düşmüştür. Sığla yağı ağacın gövdesi kazınarak elde edilir. Bir zamanlar önemli bir ihraç maddesi olan sığla yağı günümüzde bu önemini kaybetmiştir. Kahverengimsi sarı renkte olup yarı sıvıdır. Acı bir tada ve sinnamik aside benzer bir kokuya sahiptir. % 35-40 civarındaki sinnamik asidi serbest ve ester halinde bulundurur. %1 civarında uçucu yağa sahip olan sığla yağı aynı zamanda % 60 civarında sitoresin denilen triterpen asidleri de içerir. Çalışmamızda sığla yağı, Muğla Orman Bölge Müdürlüğü, Köyceğiz Orman İşletmesinden sağlandı. Yağ içinde bulunan sinnamik asit esterleri alkollü KOH çözeltisi ile hidroliz edildi. Hidroliz sonucu esterler, potasyum sinnamat ve alkollere dönüştürüldü. Potasyum sinnamat asitlendirilerek sinnamik aside sonra metil alkol ve etil alkolle tiyonil klorür varlığında esterlerine çevrildi. Alkoller, asetil klorür ile reaksiyona sokularak asetat türevlerine dönüştürüldü. Bu oluşan esterler, 1H NMR ve IR ve GC/MS gibi değişik teknikler ile karakterize edildi.

Micropropagation of Syzygium densiflorum Wall. ex Wight & arn.: An endemic and endangered semi-evergreen tree species of the Western Ghats, India

Syzygium densiflorum Wall. ex Wight & Arn. is one among the vulnerable tree species growing in the selected forest areas of the Western Ghats, India. The habitat of this tree species is being altered due to overexploitation, pressure from exotic weeds, reproductive inefficiency, microbial infection on the leaves and other problems associated. Although, this species has been included under IUCN redlist as Vulnerable (B1+2C). A study has been attempted to develop a micropropagation protocol for Syzygium densiflorum with Woody plant medium, B5 medium and Murashige skoog medium supplemented by various concentrations (0.5–2.5 mg/l) of BAP, Kn, 2,4-D, IAA and IBA alone and various combinations. The highest number of shoots (7.7 ± 0.08) was obtained from nodal explant on woody plant medium containing 1.5 mg/l BAP with 1.5 mg/l IBA achieved. The highest number of roots (3.83±0.53) and root length (3.4 ± 0.05 cm) were obtained in half strength woody plant medium supplemented with 0.5 mg/1 IBA. The rooted plantlets were successfully hardened in the paper cups containing 1:1 ratio of sand and soil and successfully transferred to field condition. About 58.5% of the saplings were survived in the natural condition.

Ebony (Diospyros celebica Bakh.) cultivation: A short review

Ebony (Diospyros celebica Bakh.) is an endemic tree species of Sulawesi. Based on the World Conservation Monitoring Centre, it is one of the protected tree species and listed in IUCN Red List under the category of vulnerable. This species is well known for its beautiful and luxurious wood. In practice, natural forests dominated by Diospyros can be managed using the Indonesian Selective Logging System (TPTI). The purpose of this paper was to determine the cultivation and management techniques of ebony plants in order to establish ebony plantations and their conservation strategy. Data were collected based on primary field observation and review of previous research written by other authors. Direct field observations were conducted to collect data on the management of seed, scarification techniques, germination, and seedling growth increment (height and diameter), while secondary data were collected from Diospyros-related studies. From the study, it was identified that the best time to produce fruit for the species was between September - November, with a germination rate, was up to 94.67%. The recommended parent trees should be over 20 years old. Seedlings were weaned when having 2 - 4 leaves with compost enriched with NPK as the best planting media. The seedling can be moved to the planting location after the age of 8-9 months with weeding as the initial treatment. The optimum growth for nine-year-old Ebony trees may reach 6.5 m in height and 6.63 cm in diameter and this growth may still be seen for 12 years old trees that showed 9 m in height and 12.81 cm in diameter. Based on this optimum growth, it is prospective to establish ebony plantation and or enrichment planting as long as the silvicultural aspect described in this study was used as a basic guideline.

Evolutionary legacy of a forest plantation tree species (Pinus armandii): Implications for widespread afforestation.

Many natural systems are subject to profound and persistent anthropogenic influence. Human‐induced gene movement through afforestation and the selective transportation of genotypes might enhance the potential for intraspecific hybridization, which could lead to outbreeding depression. However, the evolutionary legacy of afforestation on the spatial genetic structure of forest tree species has barely been investigated. To do this properly, the effects of anthropogenic and natural processes must be examined simultaneously. A multidisciplinary approach, integrating phylogeography, population genetics, species distribution modeling, and niche divergence would permit evaluation of potential anthropogenic impacts, such as mass planting near‐native material. Here, these approaches were applied to Pinus armandii, a Chinese endemic coniferous tree species, that has been mass planted across its native range. Population genetic analyses showed that natural populations of P. armandii comprised three lineages that diverged around the late Miocene, during a period of massive uplifts of the Hengduan Mountains, and intensification of Asian Summer Monsoon. Only limited gene flow was detected between lineages, indicating that each largely maintained is genetic integrity. Moreover, most or all planted populations were found to have been sourced within the same region, minimizing disruption of large‐scale spatial genetic structure within P. armandii. This might be because each of the three lineages had a distinct climatic niche, according to ecological niche modeling and niche divergence tests. The current study provides empirical genetic and ecological evidence for the site‐species matching principle in forestry and will be useful to manage restoration efforts by identifying suitable areas and climates for introducing and planting new forests. Our results also highlight the urgent need to evaluate the genetic impacts of large‐scale afforestation in other native tree species.

Anselmella kerrichi – A new pest on the reproductive reduction of an Endangered tree (Syzygium parameswaranii) of semi-evergreen Forests of the Western Ghats, India

Syzygium parameswaranii (Myrtaceae) is an endemic and endangered tree species of the Western Ghats, India. The population of this tree has severely affected by several factors including its reproductive inefficiency. Anselmella kerrichi infestation has serious consequences in S. parameswaranii in which, the host has not displayed any noticeable symptoms during the early stages and very difficult to identify. During flowering, A.kerrichi oviposit the eggs inside the flowers and affected the seed formation of the trees of Megamalai Wildlife Sanctuary. About 75-93% of the fruits were observed as under-developed and the larva feeding the ovary and ovules which affects the fruit set and seed formation. Further, this infestation reduces the reproduction and further survival of the species in the wild.

Complete chloroplast genome sequence of Liquidambar formosana, an ancient subtropical landscape plant to China

Liquidambar formosana (Hamamelidaceae) is a tertiary relic species widely distributed in subtropical areas, and is a common endemic broad-leaved tree species in south China. Here, we report and describe for the first time the complete chloroplast genome of L. formosana based on Illumina double-ended sequencing data. The complete plastid genome was 160,425 bp, which contained inverted repeats (IR) of 26,266 bp separated by a large single-copy (LSC) and a small single-copy (SSC) of 88,971 bp and 18,922 bp, respectively. The cpDNA contains 132 genes, comprising 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content of the plastome is 37.9%. The phylogenetic analysis of 18 selected chloroplast genomes demonstrated that L. formosana was close to the species Sinowilsonia henryi.

Antimicrobial Activity of Leaf Extracts of Memecylon heyneanum Benth. ex Wight & Arn.: An Endemic Tree Species of Southern Western Ghats

The genus Memecylon L. consists of more than 300 taxa, distributed mainly in the Old World. In Peninsular India, the genus Memecylon includes 34 species and nearly 18 species are endemic to the Western Ghats. Memecylon heyneayanum is an endemic and endangered tree species of Southern Western Ghats belonging to the family Melastomataceae, which is locally known as Kannavu, Kaya and Kanalai. It is a small tree growing in evergreen forests between the altitudes of 1500-2300 m asl. Being a medicinally promising species, the leaves of this evergreen tree are used to cure various ailments like diabetes, cough, leucorrhoea and menorrhagia. The powdered leaf was successively extracted with various solvents, Hexane, Petroleum ether, Chloroform, Acetone and Methanol through soxhlet apparatus. The extracts were tested for the antimicrobial activities against Bacillus cereus, Klebsiella pneumonia, Micrococcus mucilaginosus, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella terrigena, E. coli, Candida glabrata, Candida albicans and Candida sp. by agar well diffusion method at various concentrations (100µg, 150µg and 200µg) of extracts. All the extracts were effectively tested against microorganisms and also compared with standard antibiotic (Ampicilin; 100mg/ml). The maximum antimicrobial activities were obtained with maximum zone of inhibition in methanol (200µg) extract followed by Acetone, Chloroform, Petroleum ether and Hexane. The current results indicated that the potentiality of methanolic leaf extract and this can be utilized as natural drug for the treatment of several infectious diseases by microorganisms.

Whole-exome sequencing reveals a long-term decline in effective population size of red spruce (Picea rubens).

Understanding the factors influencing the current distribution of genetic diversity across a species range is one of the main questions of evolutionary biology, especially given the increasing threat to biodiversity posed by climate change. Historical demographic processes such as population expansion or bottlenecks and decline are known to exert a predominant influence on past and current levels of genetic diversity, and revealing this demo‐genetic history can have immediate conservation implications. We used a whole‐exome capture sequencing approach to analyze polymorphism across the gene space of red spruce (Picea rubens Sarg.), an endemic and emblematic tree species of eastern North America high‐elevation forests that are facing the combined threat of global warming and increasing human activities. We sampled a total of 340 individuals, including populations from the current core of the range in northeastern USA and southeastern Canada and from the southern portions of its range along the Appalachian Mountains, where populations occur as highly fragmented mountaintop “sky islands.” Exome capture baits were designed from the closely relative white spruce (P. glauca Voss) transcriptome, and sequencing successfully captured most regions on or near our target genes, resulting in the generation of a new and expansive genomic resource for studying standing genetic variation in red spruce applicable to its conservation. Our results, based on over 2 million exome‐derived variants, indicate that red spruce is structured into three distinct ancestry groups that occupy different geographic regions of its highly fragmented range. Moreover, these groups show small Ne, with a temporal history of sustained population decline that has been ongoing for thousands (or even hundreds of thousands) of years. These results demonstrate the broad potential of genomic studies for revealing details of the demographic history that can inform management and conservation efforts of nonmodel species with active restoration programs, such as red spruce.

Impacts of Global Warming on the Radial Growth and Long-Term Intrinsic Water-Use Efficiency (iWUE) of Schrenk Spruce (Picea schrenkiana Fisch. et Mey) in the Sayram Lake Basin, Northwest China

Global warming and the sharp rise in atmospheric CO2 concentrations have a profound impact on forest ecosystems. To better manage these changes, a comprehensive understanding of forest ecosystem responses to global change is essential. There is a lack of knowledge about the growth response of Schrenk spruce (Picea schrenkiana Fisch. et Mey)—an endemic tree species found in the arid Central Asian region—to climate change and rising atmospheric CO2 concentrations. In this study, core samples of Schrenk spruce were collected in the Sayram Lake Basin, Xinjiang. Tree-ring radial growth and long-term intrinsic water-use efficiency (iWUE) chronologies were established based on standard tree-ring width and stable carbon isotope methods. The relationships between atmospheric CO2 concentrations, climate, radial growth, and iWUE were analyzed. Our results indicate that the iWUE of trees in this region has continued to rise rapidly but that radial growth has not increased over the past 160 years. The main factor affecting iWUE is atmospheric CO2 concentrations (Ca), whereas the radial growth is much more sensitive to water availability. This may explain why the increase Ca has not had a fertilizer effect on the radial growth of trees.

Effect of Temperature, Light, and Storage Time on the Seed Germination of Pinus bungeana Zucc. ex Endl.: The Role of Seed-Covering Layers and Abscisic Acid Changes

Pinus bungeana Zucc. ex Endl. is an endemic conifer tree species in China with high ornamental value. In order to investigate favorable conditions for seed germination and explore the germination inhibition mechanism of this species at high temperatures, the effects of temperature, light, and storage on the mean germination time (MGT), speed of germination (SG), and total germination percentage (TGP) are evaluated here. Seeds that have either been kept still or entered into a state of dormancy at high temperature are assessed here by a recovery experiment. Furthermore, the contribution of covering layers on thermo-inhibition is analyzed here, including the way they work. This has been realized by the structural observation and via the determination of the abscisic acid (ABA) content. The results show that seeds germinate to a high percentage (approximately 90%) at temperatures of 15 or 20 °C, with or without light, whereas higher temperatures of 25 or 30 °C impeded radicle protrusion and resulted in the germination percentage decreasing sharply (within 5%). Inhibition at high temperatures was thoroughly reversed (bringing about approximately 80% germination) by placing the ungerminated seeds in favorable temperatures and incubating them for an additional 30 days. Dry cold storage did little to reduce the temperature request for germination. Embryo coverings, especially the nucellar membrane, and ABA levels both had a dominant role in seed germination regulation in response to temperature. Under favorable temperature conditions, the levels of ABA significantly decreased. Germination occurred when the levels dropped to a threshold of 15 ng/g (FW (Fresh Weight)). Incubation at a high temperature (25 °C) greatly increased ABA levels and caused the inhibition of radicle protrusion.

Genomics of the critically endangered monotypic genus Sinopora: the plastome of S. hongkongensis (Lauraceae)

Sinopora hongkongensis is a critically endangered endemic tree species restricted to Hong Kong. Here we report its plastome sequence. The S. hongkongensis plastome was 158,612 bp in length, with a large single-copy (LSC) region of 89,405 bp and a small single-copy (SSC) region of 18,205 bp, separated by two inverted repeat (IR) regions of 25,498 bp. It contained 126 genes, including 89 coding genes, 29 tRNA genes, and 8 rRNA genes. The overall GC content was 39.0%, and 43.0%, 37.7%, and 34.0%, in the IRs, LSC, and SSC regions, respectively. A phylogenetic analysis combining a subset of Lauraceae plastomes with closely related outgroup families confirms the placement of S. hongkongensis in Lauraceae and explores relationships with other genera in the family.

Uspevanje omorike (Picea omorika (Pančić) Purk.) v generativnem semenskem nasadu Počivalnik pri Postojni

Serbian spruce (Picea omorika (Pančić) Purk.) is an endemic tree species from the Balkan Peninsula. The species also thrives in Slovenia and would be an interesting minority alternative to Norway spruce (Picea abies (L.) Karst.) on some sites. This study was carried out in a Serbian spruce plantation below Počivalnik hill, between Unec and Postojna. The trees were planted in 1988 and are currently classified as a pole stand. We measured the diameters of the trees and systematically evaluated the vitality of each tree throughout the plantation. Data processing consisted of calculating the percentage of trees of each health status for each provenance and phenotype present in the plantation, creating a plantation model, and performing an analysis of variance and Tukey's post-hoc test. We found that provenance has a significant effect on the vitality of trees but not on tree diameter. Phenotype affects both the vitality of trees and tree diameter. The correlation between phenotype and tree diameter is significant within phenotypes B (type %semidichotomy%) and C (type %serbica%). Also, the impact of phenotype on diameter increment varies between the different provenances. According to our investigations, the most suitable seed material for the Dinaric karst region of Slovenia is from the Šargan provenance (read Shargan). In terms of phenotype, types C ('serbica') and F ('argentea') seem to be the most suitable. They are also the most desirable for horticultural use.

Phylogeography and population dynamics of an endemic oak (Quercus fabri Hance) in subtropical China revealed by molecular data and ecological niche modeling

High numbers of endemic plants exist in subtropical China, but there have been few investigations of the phylogeography and dynamic history for endemic tree species in this region. In this study, we explored the phylogeographic pattern of Quercus fabri, an endemic oak species in subtropical China, to assess the effects of past geographical and climatic changes on the evolutionary history of this deciduous species using three chloroplast DNA (cpDNA) fragments and the internal transcribed spacer region (ITS) and ecological niche modeling (ENM). The cpDNA fragments differentiated three phylogeographical groups among Q. fabri populations. A BEAST-derived chronogram based on the cpDNA haplotypes indicated that the initial divergence of Q. fabri probably occurred during the late Miocene (12.33 Ma), whereas haplotype divergence time could date back to the late Pliocene to early Pleistocene. ENM showed that the suitable areas contracted during the last glacial maximum (LGM) and expanded in the warm period during the Pleistocene. Consistently, both the cpDNA and ITS datasets suggested that population expansion occurred after the LGM period (ca. 13–14 kyr) for Q. fabri. Demographical analyses based on multiple genetic datasets and a coalescent-based method also suggested a shrinkage–expansion trend for the effective population sizes of Q. fabri during the glacial–interglacial periods in the Quaternary. Our results suggest that the Neogene and Pleistocene were important periods for triggering species differentiation and intraspecific diversification in Q. fabri, thereby providing insights into the effects of environmental changes in the Quaternary on the population dynamics of endemic tree species in subtropical China.

Leaf trichomes in Metrosideros polymorpha can contribute to avoiding extra water stress by impeding gall formation.

Plants inhabiting arid environments tend to have leaf trichomes, but their adaptive significance remains unclear. Leaf trichomes are known to play a role in plant defence against herbivores, including gall makers. Because gall formation can increase water loss partly through increased surface area, we tested the novel hypothesis that leaf trichomes could contribute to avoiding extra water stress by impeding gall formation, which would have adaptive advantages in arid environments. We focused on Metrosideros polymorpha, an endemic tree species in the Hawaiian Islands, whose leaves often suffer from galls formed by specialist insects, Hawaiian psyllids (Pariaconus spp.). There is large variation in the amount of leaf trichomes (0-40 % of leaf mass) in M. polymorpha. Three gall types are found on the island of Hawaii: the largest is the 'cone' type, followed by 'flat' and 'pit' types. We conducted laboratory experiments to quantify the extent to which gall formation is associated with leaf water relations. We also conducted a field census of 1779 individuals from 48 populations across the entire range of habitats of M. polymorpha on the island of Hawaii to evaluate associations between gall formation (presence and abundance) and the amount of leaf trichomes. Our laboratory experiment showed that leaf minimum conductance was significantly higher in leaves with a greater number of cone- or flat-type galls but not pit-type galls. Our field census suggested that the amount of trichomes was negatively associated with probabilities of the presence of cone- or flat-type galls but not pit-type galls, irrespective of environmental factors. Our results suggest that leaf trichomes in M. polymorpha can contribute to the avoidance of extra water stress through interactions with some gall-making species, and potentially increase the fitness of plants under arid conditions.

Otoba vespertilio (Myristicaceae), una especie nueva de Mesoamérica

Otoba vespertilio, a new endemic tree species from the Caribbean slope of Costa Rica and Panama, is described and illustrated. This species is similar to O. cyclobasis, but differs in having leaf blades with 6–8 secondary veins per side (vs. 14–17) and staminate flowers with the pedicel 2–3.6 mm long (vs. 4–5 mm) and without an extrastaminal disc surrounding the base of the staminal column (vs. extrastaminal disc present). Data on its distribution and habitat, phenology, and taxonomy are included, as are photographs of the living plant and a key to identify the four species of the genus in Mesoamerica.

Diurnal Serianthes nelsonii Merr. leaflet paraheliotropism reduces leaflet temperature, relieves photoinhibition, and alters nyctinastic behavior

The diel cycle of Serianthes nelsonii leaflet movements was characterized under four levels of shade from full sun to 22% sunlight transmission to determine the photoprotective components of diurnal leaflet movements and the relationship to patterns of nocturnal leaflet movements. Treatments also included negating paraheliotropism by re-orienting plants every 15min throughout the photoperiod such that the plants never experienced a predictable solar vector. The timing of leaflet closure to avoid high light, the shape of the diurnal curve depicting leaflet angle, and the maximum extent of leaflet closure were influenced by the shade treatments. Protection of leaf function by paraheliotropism was also influenced by shade treatment, with the full sun plants exhibiting the greatest level of protection. Leaflet heat gain was reduced 50% by leaflet movement as determined by direct measurements of leaf-to-air temperature differences. Midday quantum efficiency of photosystem II was increased 120% by leaflet movement as determined by direct measurements of pulse modulated chlorophyll fluorescence. The extent of nyctinastic leaflet closure was greatest in the high light plants that moved the most midday and least in the shaded plants that moved the least midday, indicating the extent of diurnal paraheliotropism controlled the amplitude of nocturnal leaflet movement. Serianthes nelsonii is highly skilled at using movement to reduce leaflet exposure to the solar vector, providing instantaneous behavioral control over heat gain and photoinhibition. This case study of an endemic tree species in Micronesia has added to the nascent field of conservation physiology, and indicated that heliotropism of S. nelsonii leaves may provide the species with the ability to minimize high light damage during increased temperatures associated with climate change.

Characterization of the complete plastid genome of Acer tsinglingense, an endemic tree species in China

Acer tsinglingense is an ecologically and economically important tree species in China. In this study, we characterized its whole plastid genome sequence using the Illumina sequencing platform. The complete plastid genome size of A. tsinglingense is 156,039 bp in length, including a large single-copy [LSC] region of 85,760 bp, a small single-copy [SSC] region of 18,139 bp, and a pair of inverted repeats [IRs] of 26,070 bp. The genome contains 137 genes, including 89 protein-coding genes, 40 tRNA genes, and 8 rRNA genes. The GC contents in chloroplast genome, LSC region, SSC region, and IR region were 38.0%, 36.2%, 32.4%, and 42.9%, respectively. The phylogenetic analysis based on the plastid genomes showed that A. tsinglingense was more closely related with the congeneric A. laevigatum, A. palmatum, A. wilsonii, and A. buergerianum, these species were clustered into a monophyletic clade with high bootstrap support.