Effects of forest types on leaf functional traits and their interrelationships of Pinus massoniana coniferous and broad‐leaved mixed forests in the subtropical mountain,Southeastern China

Leaf functional traits are widely used to detect and explain adaptations that enable plants to live under various environmental conditions. This study aims to determine the difference in leaf functional traits among four forest types of Pinus massoniana coniferous and broad‐leaved mixed forests by leaf morphological, nutrients, and stoichiometric traits in the subtropical mountain, Southeastern China. Our study indicated that the evergreen conifer species of P. massoniana had higher leaf dry matter content (LDMC), leaf C content, C/N and C/P ratios, while the three deciduous broad‐leaved species of L. formosana, Q. tissima, and P. strobilacea had higher specific leaf area (SLA), leaf N, leaf P nutrient contents, and N/P ratio in the three mixed forest types. The results showed that the species of P. massoniana has adapted to the nutrient‐poor environment by increasing their leaf dry matter for higher construction costs thereby reducing water loss and reflects a resource conservation strategy. In contrast, the three species of L. formosana, Q. tissima, and P. strobilacea exhibited an optimized resource acquisition strategy rather than resource conservation strategy in the subtropical mountain of southeastern China. Regarding the four forest types, the three mixed forest types displayed increased plant leaf nutrient contents when compared to the pure P. massoniana forest, especially the P. massoniana–L. formosana mixed forest type (PLM). Overall, variation in leaf functional traits among different forest types may play an adaptive role in the successful survival of plants under diverse environments because leaf functional traits can lead to significant effects on leaf function, especially for their acquisition of nutrients and use of light. The results of this study are beneficial to reveal the changes in plant leaf functional traits at the regional scale, which will provide a foundation for predicting changes in leaf traits and adaptation in the future environment.     

Acid-catalyzed steam pretreatment of lodgepole pine and subsequent enzymatic hydrolysis and fermentation to ethanol

Utilization of ethanol produced from biomass has the potential to offset the use of gasoline and reduce CO(2) emissions. This could reduce the effects of global warming, one of which is the current outbreak of epidemic proportions of the mountain pine beetle (MPB) in British Columbia (BC), Canada. The result of this is increasing volumes of dead lodgepole pine with increasingly limited commercial uses. Bioconversion of lodgepole pine to ethanol using SO(2)-catalyzed steam explosion was investigated. The optimum pretreatment condition for this feedstock was determined to be 200 degrees C, 5 min, and 4% SO(2) (w/w). Simultaneous saccharification and fermentation (SSF) of this material provided an overall ethanol yield of 77% of the theoretical yield from raw material based on starting glucan, mannan, and galactan, which corresponds to 244 g ethanol/kg raw material within 30 h. Three conditions representing low (L), medium (M), and high (H) severity were also applied to healthy lodgepole pine. Although the M severity conditions of 200 degrees C, 5 min, and 4% SO(2) were sufficiently robust to pretreat healthy wood, the substrate produced from beetle-killed (BK) wood provided consistently higher ethanol yields after SSF than the other substrates tested. BK lodgepole pine appears to be an excellent candidate for efficient and productive bioconversion to ethanol.     

长白山垂直自然带弹尾纲物种概况

以长白山弹尾纲为研究对象, 基于1758‒2022年度发表的分类学和生态学文献资料, 编制了长白山垂直自然带弹尾纲物种名录, 分析了首次发表物种的学者贡献、出版物、发表时间和各属沿海拔梯度的分布情况。本研究共梳理弹尾纲物种92种, 隶属于3目11科46属, 长角䖴目、原䖴目和愈腹䖴目的物种分别占比61%、31%和8%, 其中长角䖴目的等节䖴科(该类群物种数占总体比例, 26%)、长角䖴科(16%)和鳞䖴科(16%)、原䖴目的棘䖴科(26%)是该地区的主要类群。统计的92种长白山弹尾纲物种由36位学者首次定名和报道, 中国学者占主要贡献(33%), 其次为波兰(11%)、瑞典(11%)、俄罗斯(8%)和美国(8%); 相关论文多发表在国际期刊上, Zootaxa是发表的主要期刊。基于海拔梯度的统计发现, 鳞䖴属(Tomocerus)和符䖴属(Folsomia)的物种沿海拔梯度的分布范围最广(海拔800‒1,700 m), 分布在海拔800 m (15个物种)、1,100 m (20个物种)和1,400 m (14个物种)的物种最多。基于以上结果, 本文讨论了长白山弹尾纲分类学现状和发展前景。     

腊尔山区苗族学生头面部形态特征

本项目对1896例腊尔山区6~16岁苗族学生（男919例,女977例）进行了人体测量,测量了10项头面部形态指标,并根据公式计算13项头面部指数值。结果表明,苗族学生头面部各指标均值随年龄增长而增加,同年龄段头面部各指标均值男生一般高于女生,且多数年龄段差异有统计学意义;男性的头长宽的、形态面的、形态上面的、容貌面的、颧额宽的、容貌上面的和容貌上面高的指数以及女性的形态面的、形态上面的、容貌面的、颧下颌宽度的、容貌上面高的指数随年龄增长总体趋势是先增加后递减;男性头面高的以及女性的头长高的、头宽高的和头面宽的指数随年龄增长逐渐增加;男女性之间的头长高的、头宽高的和额顶宽的指数比较显示,多数年龄段差异有统计学意义;苗族学生头型以中头型、高头型、阔头型多见,面型以阔面型、阔上面型为主;相对于其他族群,腊尔山苗族男生面型短而宽,头型偏长,女生面型偏短,头型稍偏长而窄。腊尔山苗族学生头面部特征与融水苗族、土家族等族群较为接近,与哈萨克族、新乡汉族相距较远。     

A field test of the audibility of urban versus rural songs in mountain chickadees

Anthropogenic noise can mask avian vocalizations, and several urban‐dwelling species adjust frequency or amplitude of vocalizations in ways that appear to compensate for increased noise levels. Playback studies have investigated whether receivers differentiate between signals produced by rural and urban males, but it is difficult to determine whether differential response to stimulus reflects differences in audibility versus perceived differences in male signals/condition that result from urban settlement. Here, we performed paired‐playback trials to determine whether mountain chickadees (Poecile gambeli) differentiate urban versus rural songs when both stimuli were broadcast within noise. For each playback, stimuli were played in short bouts starting at a low signal‐to‐noise ratio and increasing in relative amplitude with each successive bout. If the primary function of adjusted urban songs is propagation in noise, we hypothesized that focal males would respond sooner to urban versus rural playbacks (detect at lower signal‐to‐noise ratios). If urban songs solely encode information about the male's condition (such as increased aggression), then we predicted only a differential aggressive response to playbacks once detected. If urban songs both increase propagation and embed information on male condition, we predicted a combination of both response types. We found no difference in latency to first response in urban versus rural songs, but some evidence for differential aggression to playback dependent on both stimulus type (urban vs. rural) and local ambient noise levels; focal males in noisy (urban) sites responded aggressively to both stimulus types, whereas focal males in quiet (rural) sites responded more aggressively to urban than to rural stimuli. This context‐dependent discrimination may be the result of increased aggression in urban habitats, improved communication in noisy habitats by urban signallers and receivers, or some combination of the two.     

Context‐dependent biotic interactions control plant abundance across altitudinal environmental gradients

Many biotic interactions influence community structure, yet most distribution models for plants have focused on plant competition or used only abiotic variables to predict plant abundance. Furthermore, biotic interactions are commonly context‐dependent across abiotic gradients. For example, plant–plant interactions can grade from competition to facilitation over temperature gradients. We used a hierarchical Bayesian framework to predict the abundances of 12 plant species across a mountain landscape and test hypotheses on the context‐dependency of biotic interactions over abiotic gradients. We combined field‐based estimates of six biotic interactions (foliar herbivory and pathogen damage, fungal root colonization, fossorial mammal disturbance, plant cover and plant diversity) with abiotic data on climate and soil depth, nutrients and moisture. All biotic interactions were significantly context‐dependent along temperature gradients. Results supported the stress gradient hypothesis: as abiotic stress increased, the strength or direction of the relationship between biotic variables and plant abundance generally switched from negative (suggesting suppressed plant abundance) to positive (suggesting facilitation/mutualism). For half of the species, plant cover was the best predictor of abundance, suggesting that the prior focus on plant–plant interactions is well‐justified. Explicitly incorporating the context‐dependency of biotic interactions generated novel hypotheses about drivers of plant abundance across abiotic gradients and may improve the accuracy of niche models.     

Mutual mate choice by mountain pine beetles: size‐dependence but not size‐assortative mating

1. Mutual mate choice may be rare, occurring when both sexes invest heavily in reproduction, mating opportunities are abundant, and individuals differ in quality. 2. Mountain pine beetles, Dendroctonus ponderosae (Curculionidae: Scolytinae) appear to meet the conditions for mutual mate choice. We introduced males to females in breeding sites and observed the occurrence and speed of a male entering a female's gallery. We tested for consequences of mutual mate choice, namely condition‐dependent choosiness and assortative mating. 3. Males were more likely to enter a female's gallery when the gallery was in a smaller tree with less resin production and when the gallery was larger. Female body size and condition did not influence the probability of entry. Larger males were less likely to enter a gallery than were smaller males, probably because of size‐dependent choosiness rather than physical limitations. 4. Small males took longer to enter galleries of large females than of small females, whereas large males entered as quickly into galleries of large females as small females. This suggests size‐dependent choosiness by females. 5. No assortative mating by body size was detected, probably because males appeared to choose on the basis of female‐associated resources rather than on female traits.     

Fracture toughness of mountain gorilla (Gorilla gorilla beringei) food plants

Mountain gorillas, the largest extant primates, subsist almost entirely on plant matter. Moreover, their diet includes a substantial amount of structural material, such as bark and stems, which other primates tend to avoid. Accordingly, the robust masticatory apparatus of gorillas may be adaptive to this presumably tough diet; however, quantitative information on this subject is lacking. In this study the fracture toughness of mountain gorilla foods was examined for the first time. Samples of 44 food plants from Bwindi-Impenetrable National Park (BINP) and Mgahinga Gorilla National Park (MGNP) were tested. These parks are inhabited by two gorilla populations that regarded by some as being distinct at the subspecific taxonomic level. Although food toughness did not differ between the two populations, both diets contained tough items. Tree barks were the toughest food items (varying from 0.23 to 8.2 kJ/m2), followed by shrub barks, pith, and stems. The toughness of leaves and fruit was negligible compared to that of bark. The toughness of bamboo was low in comparison to the toughest food items. Accordingly, the prominent toughness of bark, pith, and stems may be key factors in the evolution of orofacial robusticity in mountain gorillas.     

Risk of Disease Transmission between Conservation Personnel and the Mountain Gorillas: Results from an Employee Health Program in Rwanda

Humans and gorillas share 97% of their genetic makeup which means the risk of disease transmission between the two is potentially high. Humans with high exposure and whose exposure-related activity can most easily be managed are park conservation personnel. In June 2001, the Morris Animal Foundations Mountain Gorilla Veterinary Project initiated a health program for all employees working in Rwandas Parc National des Volcans in collaboration with in-country government and nongovernmental agencies. The goal is to improve the health of conservation personnel and reduce the risk of zoonotic disease transmission between employees and the parks mountain gorillas. Employees annually receive a clinical examination and laboratory testing, and provide a clinical history, In 2002, analyses were performed on the dataset of 127 employees to identify potential risk factors associated with positive laboratory tests. Considering all fecal tests combined, 70.1% were positive for one or more pathogenic organisms. A high percentage (> 80%) tested positive on viral antibody titer testing for various communicable diseases including measles, chickenpox, and hepatitis. On multivariate analysis, the main risk factor for testing positive for any pathogenic organism was use of a pit latrine at home. Vaccination against childhood communicable diseases and improved human waste disposal could be critical control points for preventing disease transmission to mountain gorillas. Program results have been shared with local health officials to aid in their efforts to improve village health and sanitation standards, and with park employers as a basis for ongoing employee health education.The Mountain Gorilla Veterinary Project 2002 Employee Health Group members are listed in Appendix 1. by area of contribution.     

Comparative analysis of leaf trichome structure and composition of epicuticular flavonoids in Finnish birch species

The morphology, ultrastructure, density and distribution of trichomes on leaves of Betula pendula, B. pubescens ssp. pubescens, B. pubescens ssp. czerepanovii and B. nana were examined by means of light, scanning and transmission electron microscopy. The composition of flavonoids in ethanolic leaf surface extracts was analysed by high pressure liquid chromatography. All taxa examined contained both glandular and non-glandular trichomes (short and/or long hairs) but differed from each other in trichome ultrastructure, density and location on the leaf. Leaves of B. pubescens were more hairy than those of B. pendula, but the latter species had a higher density of glandular trichomes. Of the two subspecies of B. pubescens, leaves of ssp. pubescens had more short hairs on the leaf surface and four times the density of glandular trichomes of leaves of ssp. czerepanovii, whereas, in the latter subspecies, short hairs occurred largely on leaf veins, as in B. nana. The glandular trichomes were peltate glands, consisting of medullar and cortical cells, which differed structurally. Cortical cells possessed numerous small, poorly developed plastids and small vacuoles, whereas medullar cells had several large plastids with well-developed thylakoid systems and fewer vacuoles. In B. pubescens subspecies, vacuoles of the glandular cells contained osmiophilic deposits, which were probably phenolic, whereas in B. pendula, vacuoles of glandular trichomes were characterized by the presence of numerous myelin-like membranes. The composition of epicuticular flavonoids also differed among species. The two subspecies of B. pubescens and B. nana shared the same 12 compounds, but five of these occurred only in trace amounts in B. nana. Leaf surface extracts of B. pendula contained just six flavonoids, three of which occurred only in this species. In summary, the structure, density and distribution of leaf trichomes and the composition of epicuticular flavonoids represent good taxonomic markers for Finnish birch species.