Changes in the parameters of skin capillaries during the adaptation of students from the countries of Asia, Africa and Latin America

Time-dependent changes in diameters of various parts of the capillaries, distances between loops of the skin papillary capillaries in the nail wall and number of functioning capillaries per 1 mm2 of the skin surface have been studied biomicroscopically in foreign students, arrived from hot countries, during the process of their adaptation. Reorganization of these skin capillary parameters, actively participating in processes of heat exchange, demonstrate a time-dependent character. Therefore, by means of regressive analysis it is possible to approximate dynamics of the initial data using suitable theoretical models. The dynamics of average meanings of the capillary diameters in the arterial part subordinates to the hyperbolic dependence, changes of other parameters approach the rectilinear regression.     

PREFURROW BEHAVIOR OF THE EQUATORIAL SURFACE IN ARBACIA LIXULA EGGS*

Study of equatorial surface activity occurring immediately before furrowing in Arbacia lixula (=pustulosa) eggs was undertaken to learn more about the establishment of the cleavage mechanism. Behavior of echinochrome granules in the egg surface, observed and recorded with a Nikon AFM camera, was used as the indicator of surface events. An hour after fertilization A. lixula eggs were slightly flattened and periodically photographed until the furrow appeared. By measuring regional changes in the concentration of echinochrome granules, we found that a band of equatorial surface approximately 22 μm wide, which comprises about 32% of the uncleaved egg surface, shrinks about 34% and forms a densely pigmented band averaging 15 μm wide. This contraction in the equatorial zone is accompanied by expansion or stretching in the subequatorial surfaces. The possible relation between these events and formation of the microfilamentous contractile ring is discussed.     

Climate and vegetation in China IV. Distribution of tree species along the thermal gradient

The aim of this study was to examine correlations between vegetational zones and thermal climate on the basis of analysis of the thermal distribution of main-component trees in each zone. The whole and main thermal distribution ranges for 73 tree species were obtained from their distributions along the warmth index (WI) gradicnt. Cluster analysis using the WI values at the upper and lower limits of the main distribution ranges as parameters gave seven species groups. The geographical distributions of the species in each group were described. Moreover, the frequency distribution curves of the seven species groups were determined along the WI grandient, and four borderlines (lines I, II, III and IV) were found among them. The WI values at the lines I, II and IV were 50, 90, 175°C month, respectively, and corresponded to boundaries between the subarctic and cool-temperate zones (I), the cool-and warm-temperate zones (II) and the warmtemperated and subtropical/tropical zones (IV), respectively. Line III corresponded to a WI of 135°C month. The WI values at the forest limit and at the lower limit of the subarctic forest were estimated, and their averages were 15.2 and 49.6°C month, respectively. In conclusion, thermal climatic zones in China could be divided by the following WI values: alpine (arctic) zone, WI<15; subarctic zone, 15–50; cool-temperate zone, 50–90; warm-temperate zone, 90–175; subtropical/tropical zone >175°C month.     

On the Classification of Forest Vegetation in Xishuangbanna,Southern Yunnnan

Xishuangbanna of southern Yunnan is a region of extremely interest to biologists and also a hotspot for biodiversity conservation . It is located in a transitional zone from tropical Southeast Asia to temperate East Asia biogeographically. The present paper reviewed vegetation types of Xishuangbanna and suggested a revised classification system based on theupdated study results over the last two decades . By combining physiognomic and floristic characteristics with ecological performances and habitats , the primary forest vegetation in Xishuangbanna can be organized into four main vegetation types: tropical rain forest, tropical seasonal moist forest, tropical montane evergreen broad-leaved forest and tropical monsoon forest. The tropical rain forest can be classified into two subtypes , i. e. tropical seasonal rain forest in the lowlands and tropical montane rain forest on higher elevations. The tropical seasonal rain forest in this region shows similar forest profile and physiognomic characteristics to those of equatorial lowland rain forests and is a type of world tropical rain forest. Because of conspicuous similarity on floristic composition , the tropical seasonal rain forest in Xishuangbanna is a type of tropical Asian rain forest . However , since the tropical seasonal rain forest occurs at the northern edge of tropical SE Asia, it differs from typical lowland rain forests in equatorial areas in maintaining some deciduous trees in the canopy layer , fewer megaphanerophytes and epiphytes but more abundant lianas and more plants with microphyll . It is a type of semi-evergreen rain forest at the northern edge of the tropical zone . The tropical montane rain forest occurs in wet montane habitats and is similar to the lower montane rain forests in equatorial Asia in floristic composition and physiognomy . It is a variety of lower montane rain forests at the northern tropical edges of tropical rain forests . The tropical seasonal moist forest occurs on middle and upper limestone mountains and is similar to the tropical montane evergreen broad-leaved forest of the region in physiognomy, but it differs from the latter in floristic composition. The monsoon forest in Xishuangbanna is a tropical deciduous forest under the influence of a strong monsoon climate and is considered to be a transitional vegetation type between tropical rain forest and savanna in physiognomy and distribution. The tropical montane evergreen broad- leaved forest is the main vegetation type in mountain areas . It is dominated by the tree species of Fagaceae , Euphorbiaceae , Theaceae and Lauraceae in majority. It differs from the tropical montane rain forests in lack of epiphytes and having more abundant lianas and plants with compound leaves . It is considered to be a distinct vegetation type in the northern margin of mainland southeastern Asia controlling by a strong monsoon climate, based on its floristic and physiognomic characteristics.     

论滇南西双版纳的森林植被分类

本文基于多年研究成果的总结,对西双版纳森林植被的分类、主要植被类型及其特征进行了系统归纳,并讨论了它们与世界类似热带森林植被的关系。以群落的生态外貌与结构、种类组成和生境特征相结合作为植被分类的原则和依据,可以将西双版纳的热带森林植被分类为热带雨林、热带季节性湿润林、热带季雨林和热带山地常绿阔叶林四个主要的植被型,包括有至少二十个群系。热带雨林包括热带季节雨林和热带山地(低山)雨林二个植被亚型。热带季节雨林具有与赤道低地热带雨林几乎一样的群落结构和生态外貌特征,是亚洲热带雨林的一个类型,但由于发生在季风热带北缘纬度和海拔的极限条件下,受到季节性干旱和热量不足的影响,在其林冠层中有一定比例的落叶树种存在,大高位芽植物和附生植物较逊色而藤本植物和在叶级谱上的小叶型植物更丰富,这些特征又有别于赤道低地的热带雨林。热带山地雨林是热带雨林的山地亚型,是该地区热带山地较湿润生境的一种森林类型,它在植物区系组成和生态外貌特征上类似于热带亚洲的低山雨林,隶属于广义热带雨林植被型下的低山雨林亚型。热带季节性湿润林分布在石灰岩山坡中、上部,在群落外貌上类似热带山地常绿阔叶林但在植物区系组成上与后者不同,它是石灰岩山地垂直带上的一种植被类型。热带季雨林是分布在该地区开阔河谷盆地及河岸受季风影响强烈的生境的一种热带落叶森林,是介于热带雨林与萨王纳之间的植被类型。热带山地常绿阔叶林(季风常绿阔叶林)是西双版纳的主要山地植被类型,它分布在热带季节雨林带之上偏干的山地生境。它在植物区系组成上不同于该地区的热带季节雨林,在生态外貌特征上亦不同于热带山地雨林,是发育在受地区性季风气候强烈影响的热带山地的一种森林植被类型。     

Reforestation and surface cooling in temperate zones: Mechanisms and implications

Land‐use/cover change (LUCC) is an important driver of environmental change, occurring at the same time as, and often interacting with, global climate change. Reforestation and deforestation have been critical aspects of LUCC over the past two centuries and are widely studied for their potential to perturb the global carbon cycle. More recently, there has been keen interest in understanding the extent to which reforestation affects terrestrial energy cycling and thus surface temperature directly by altering surface physical properties (e.g., albedo and emissivity) and land–atmosphere energy exchange. The impacts of reforestation on land surface temperature and their mechanisms are relatively well understood in tropical and boreal climates, but the effects of reforestation on warming and/or cooling in temperate zones are less certain. This study is designed to elucidate the biophysical mechanisms that link land cover and surface temperature in temperate ecosystems. To achieve this goal, we used data from six paired eddy‐covariance towers over co‐located forests and grasslands in the temperate eastern United States, where radiation components, latent and sensible heat fluxes, and meteorological conditions were measured. The results show that, at the annual time scale, the surface of the forests is 1–2°C cooler than grasslands, indicating a substantial cooling effect of reforestation. The enhanced latent and sensible heat fluxes of forests have an average cooling effect of ?2.5°C, which offsets the net warming effect (+1.5°C) of albedo warming (+2.3°C) and emissivity cooling effect (?0.8°C) associated with surface properties. Additional daytime cooling over forests is driven by local feedbacks to incoming radiation. We further show that the forest cooling effect is most pronounced when land surface temperature is higher, often exceeding ?5°C. Our results contribute important observational evidence that reforestation in the temperate zone offers opportunities for local climate mitigation and adaptation.     

Sialyl glycoprotein distribution on the plasma membrane of ejaculated ram spermatozoa

Localization of sialyl residues on unfixed ejaculated ram sperm membrane using the direct covalent probes of either ferritin hydrazide or latex hydrazide revealed a unique regional distribution on the plasmalemma covering the sperm head only. Three different labelling zones were identified based on the intensity and the nature of the sialyl glycoconjugates: a patchy-like zone which included the plasma membrane overlaying the post-nuclear cap and the convex side of the apical body of the acrosome; highly ordered heavily labelled zones including the plasmalemma adjacent to the concave apical body of the acrosome and to the posterior part of the equatorial acrosomal segment; a paucity-labelling zone which included the plasma membrane underlying the principal acrosomal region and the anterior part of the equatorial acrosomal segment. The possible physiological role of the highly ordered labelled zones is discussed.     

Intra- and infra-specific morphological variation in selected coccolithophore species in the equatorial and subequatorial Pacific Ocean

The ecological preferences of morphological groups within major coccolithophore taxa were studied in surface water samples from the equatorial and subequatorial Pacific Ocean. Emiliania huxleyi was subdivided into three morphological groups: Type A, Type C, and variety corona. The most probable factors limiting the occurrence of E. huxleyi Types A and C were high temperatures and low nutrient concentrations, respectively. E. huxleyi var. corona had an affinity for oligotrophic conditions. Calcidiscus leptoporus ssp. small was adapted to fertile waters. Umbilicosphaera foliosa and Umbilicosphaera sibogae preferred mesotrophic upwelling waters and stratified marginal waters surrounding the upwelling front, respectively. Among the three Umbellosphaera tenuis morphotypes observed in this study (Types I, III, and IV), only Type I was found in very warm tropical surface. Both Types III and IV were found in subtropical waters, and Type III differed from Type IV in that its distribution was constrained to hemi-pelagic waters. Habitat segregation among the morphotypes of major taxa indicates that the observed global distributions of these major taxa are, in fact, combinations of discrete morphological groups.     

Latitudinal pattern of mountain vegetation zonation in southern and eastern Asia

A new scheme of altitudinal and latitudinal vegetation zonation is proposed for eastern Asia. The latitudinal patterns of mountain vegetation zonation show a clear boundary at ca. 20°–30° N. For the tropical mountains south of 20° N, the altitudinal series includes tropical lowland, tropical lower montane, and tropical upper montane zones. For the temperate mountains north of 30° N, the series includes temperate lowland, temperate lower montane, and temperate upper montane zones. The mountains located between 20° and 30° N show a transitional zonation pattern; the lower two zones are comparable to the lower two of the tropical zonation (tropical lowland and tropical lower montane), and the upper two zones are comparable to those of the temperate zonation (temperate lower montane and temperate upper montane). The tropical upper montane zone is not found north of 20°–30° N, while the tropical lower montane zone reaches down to sea level and constitutes the temperate lowland zone. Thus the zonation between 20° and 30° N includes tropical lowland, tropical lower montane/temperate lowland, temperate lower montane, and temperate upper montane zones. The latitudinal series of lowland rain forests follows the scheme of climatic division into tropical, subtropical/warm-temperate, cool-temperate and cold-temperate, with a shift of the respective life forms, evergreen, evergreen notophyllous, deciduous, and evergreen needle-leaved. The tropical lower montane forest can be correlated to the horizontal subtropical/ warm-temperate zone. The temperate altitudinal and latitudinal zonations above 30° N are correlated and show an inclined parallel pattern from high altitudes in the south to low altitudes down to sea level in the north.     

El Niño and tree growth near Jerusalem over the last 20 years

A strong correlation is observed between an El Niño index (anomalies in tropical Pacific sea surface temperature) and rainfall in the Judean foothills near Jerusalem over the past 20 years. These relationships clearly influenced the growth of local pine trees, as reflected in the width of their annual tree rings. The ability to predict El Niño events about a year in advance lend a special significance to relationships reported here for ecology, agriculture and water management in this climatic transition zone. To help explain the observed, long-range teleconnection we propose a possible mechanism based on a newly identified direct cloud connection between equatorial Africa (more directly affected by El Niño) and the Southeastern Mediterranean shoreland. The penetration and contribution of the moisture current from equatorial Africa to this region may depend on a shift in the usual rain generating moisture currents to southwesterly trajectories (passing over north Africa). The occurrence of such shifts is supported by the observed decrease in the mean ¹⁸O content of the local precipitation during El Nino winters.     

Structural comparison of tropical montane rain forests along latitudinal and altitudinal gradients in south and east Asia

Geographical patterns of altitudinal zonation, floristic composition, and structural features of tropical montane rain forests were examined along latitudinal gradients in south and east Asia. On equatorial mountains, the tropical montane rain forests occur above 1000 m. Toward middle latitudes, they come farther down and reach sea level at c. 35° N. Thus, the forests are equivalent to the subtropical rain forests of the latitudinal, horizontal zonation series. They exhibit gradual changes in floristic composition and structure along both altitudinal and latitudinal gradients. On equatorial mountains, they are divided into three types, i.e. tropical lower montane, upper montane, and subalpine forests. The three tree regeneration types, having emergent, sporadic and inverse-J type stem-diameter class frequency distributions, coexist in the lower montane forests, but the upper and subalpine forests display only the inverse-J type species with a few species of the sporadic type. Toward the northern latitudinal limit, the distinction between the three tropical montane forest zones in equatorial mountains becomes less clear. This can be explained by temperature conditions: on equatorial mountains, a temperature sum of 85° C months which controls the upper limit of the lower montane forests, and a coldest month mean temperature of-1° C which controls the evergreen broad-leaved trees, appear at c. 2500 and c. 4000 m respectively. The altitudinal range between 2500 m and 3800 m, which is the upper forest limit, is covered by upper montane and subalpine forests. On the other hand, at the latitudinal northern limit, the tropical upper montane and subalpine forests cannot exist because the above mentioned two temperature conditions occur at nearly the same point. Thus, at the northern latitudinal limit of the tropical montane forests, the three zones of equatorial mountains amalgamate into a single subtropical lowland forest community. This is due to the seasonal temperature climate in middle latitudes in, e.g., central Japan and central China.A part of this paper was presented as an oral presentation at the Vth International Congress of Ecology, Yokohama 23–30.8.1990.     

气候变化背景下中国南方地区季节性干旱特征与适应Ⅴ.南方地区季节性干旱特征分区和评述

在干旱特征研究的基础上开展季节性干旱分类分区,可为不同干旱区域应对全球气候变化、制定抗旱减灾对策和防控技术提供理论依据.以国家标准中的气象干旱、农业干旱指标为主要依据,利用南方地区268个气象台站1959-2008年的气候资料,在分析南方地区季节性干旱的气候背景和分布特征的基础上,采用综合因子与主导因子相结合方法、逐级指标筛选法,综合灾害分析和聚类分析方法,对季节性干旱进行3级分区.一级分区以年干燥度和季干燥度为主要指标,以年尺度和主要作物生长季的降水量为辅助指标,将南方区域分为半干旱区、半湿润区、湿润区和极湿润区4个一级区;在此基础上再划分为川滇高原山地温凉半干旱区,江北温暖半湿润区、华南暖热半湿润区和西南高原温凉半湿润区3个半湿润区,长江流域温热湿润区、华南暖热湿润区和西南山地温暖湿润区3个湿润区,以及华南暖热极湿润区和江南西南山区温凉极湿润区2个极湿润区,共9个二级干旱分区.最后基于多个干旱指标的干旱频率和干旱强度,将南方区域分成29个三级干旱区.在分区基础上对不同季节性干旱特征分区分布情况、干旱特点及对农业生产影响进行评述,并提出了防旱避灾措施.     

Quantitative investigations on the topography of twelve structural elements of the male gonad

For elucidating the problem whether the tissue composition of the male gonad is identical or different in the equatorial zone and polar zones of the organ, 104 left testes were studied obtaining them from the cadaver of patients dying from various acute and chronic diseases not affecting the endocrine system. In the histological preparations of the polar and equatorial zones of the testis, the proportion [%] were calculated of 6 types of convoluted tubules designated with numbers from 1 to 6 in the sequence of decreasing spermatogenic activity, and by the morphometric method, the proportions [%] were determined of the tubular lumina, spermatogenic epithelium, tubular membrane, stroma, blood vessels, and LEYDIG's cells. In the whole analysed group, only tubules type 2 were more numerous in the equatorial part, while tubules type 6 prevailed in the polar parts. The lumina of the tubules occupied a greater % of the testicular structure in the polar parts as compared with the central part. Other tissue elements were present in similar amounts or the differences between their amounts in these parts were only nearly significant statistically. The study showed also that the number of type 1 tubules decreased significantly with progressing age, while the number of type 6 tubules increased. A statistically significant fall of the proportion [%] of the spermatogenic epithelium and increased proportion of tubular membranes and stroma were another age-related changes. It is worth stressing that these age-related processes progressed parallelly in the equatorial part and in the polar parts of the testis which suggest that ageing of the organ occurs simultaneously in the whole gonad.     

Exine morphology and ultrastructure of Duplicisporites from the Triassic of Italy

A morphological study of dispersed Circumpolles pollen grains from the Upper Triassic of the Southern Alps has been initiated with the genus Duplicisporites. Individual pollen grains were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Seen with SEM the pollen surface is finely verrucate with low verrucae of different sizes. A sub‐equatorial continuous rimula is clearly visible. The proximal trilete scar is small and indistinct. TEM images reveal a bi‐layered exine. The ectexine is formed by numerous small, closely packed, granulae subdivided by irregularly‐spaced cavities. In the region of the subequatorial canal, the ectexine becomes thinner, about 1/3 of the usual thickness. At places, the ectexine is slightly separated from the underlying endexine. The endexine is prominent and significantly darker than the ectexine. It is homogeneous and of constant thickness. On the basis of its older age, with respect to Classopollis, the present ultrastructural dataset provides information on the possible origin of cheirolepidiaceous‐type morphology.     

Geological History,Flora, and Vegetation of Xishuangbanna,Southern Yunnan,China1

Xishuangbanna of southern Yunnan is biogeographically located at a transitional zone from tropical Southeast (SE) Asia to subtropical East Asia, and is at the junction of the Indian and Burmese plates of Gondwana and the Eurasian plate of Laurasia. The flora of the region consists of a recorded 3336 native seed plant species, belonging to 1140 genera in 197 families, among which 83.5 percent are tropical genera and 32.8 percent are endemic to tropical Asia, suggesting a strong affinity to tropical Asian flora. The vegetation of Xishuangbanna is organized into four forest types: tropical rain forest, tropical seasonal moist forest, tropical montane evergreen broad‐leaved forest, and tropical monsoon forest. The tropical rain forest in Xishuangbanna has the same floristic composition of families and genera as some lowland equatorial rain forests in SE Asia, and is dominated (with a few exceptions) by the same families both in species richness and stem dominance. The exceptions include some deciduous trees in the canopy layer, fewer megaphanerophytes and epiphytes, and a higher abundance of lianas and microphyllic plants. We consider the tropical rain forest of Xishuangbanna as a type of tropical Asian rain forest, based on their conspicuous similarities in ecological and floristic characteristics.     

Fiber stress profiles in the left ventricle of the heart during diastole: Effects of distension and hypertrophy

Pressure-volume and volume-dimensions relationships, obtained from excised dog left ventricles were used for calculating the stresses acting along the longitudinal axis of the individual myocardial fibers. The calculations were based on a set of empirical and theoretical equations. The pressure-volume relationship as well as the volume-dimensions relationships for the excised left ventricle were expressed in the form of empirical equations; the fiber orientation was written as a function of the fiber location within the left ventricular wall; finally, the fiber stress was determined by means of theoretically derived formulas. Simultaneous solutions for the fibers of a meridian cut through the left ventricular myocardial shell were obtained by means of a digital computer and presented in the form of diagrams. The results showed that at low degrees of distension of the left ventricle there are two zones of higher stresses at the equatorial area, one near the epicardium and one near the endocardium. As the distension proceeds under the effect of progressively increasing intraventricular pressure, these two zones become less well defined, whereas a new zone of higher stresses appears near the apex. At high degrees of distension, the ventricle assumes a more spherical shape and the equatorial zones of higher stresses are replaced by zones of lower stresses. Increase in the myocardial mass results in appearance of the equatorial lower stress zones at lower degrees of distension.     

INCREASED RATES OF MOLECULAR EVOLUTION IN AN EQUATORIAL PLANT CLADE: AN EFFECT OF ENVIRONMENT OR PHYLOGENETIC NONINDEPENDENCE?

A recent study of environmental effects on rates of molecular evolution in the plant subgenus Mearnsia shows that species occurring in more equatorial latitudes have higher rates of substitution in rDNA sequences as compared to their more southerly congeners (Wright et al. 2003). However, we believe that the statistical approach employed by Wright et al. (2003) insufficiently accounts for the phylogenetic nonindependence of the species examined, given that all six equatorial species of Mearnsia form a clade. To distinguish between the effect of latitude and that of phylogenetic nonindependence, we have employed a variety of comparative approaches that use independent contrasts to test for an effect of environment across this entire subgenus. We find very little evidence for an effect of latitude on rate of molecular evolution using these approaches and believe that the shared evolutionary history of the clade is a plausible explanation of the apparent rate difference between equatorial and subequatorial Mearnsia species.     

The impact of accelerating land-use change on the N-Cycle of tropical aquatic ecosystems: Current conditions and projected changes

Published data and analyses from temperate and tropical aquatic systems are used to summarize knowledge about the potential impact of land-use alteration on the nitrogen biogeochemistry of tropical aquatic ecosystems, identify important patterns and recommend key needs for research. The tropical N-cycle is traced from pre-disturbance conditions through the phases of disturbance, highlighting major differences between tropical and temperate systems that might influence development strategies in the tropics. Analyses suggest that tropical freshwaters are more frequently N-limited than temperate zones, while tropical marine systems may show more frequent P limitation. These analyses indicate that disturbances to pristine tropical lands will lead to greatly increased primary production in freshwaters and large changes in tropical freshwater communities. Increased freshwater nutrient flux will also lead to an expansion of the high production, N- and light-limited zones around river deltas, a switch from P- to N-limitation in calcareous marine systems, with large changes in the community composition of fragile mangrove and reef systems. Key information gaps are highlighted, including data on mechanisms of nutrient transport and atmospheric deposition in the tropics, nutrient and material retention capacities of tropical impoundments, and N/P coupling and stoichiometric impacts of nutrient supplies on tropical aquatic communities. The current base of biogeochemical data suggests that alterations in the N-cycle will have greater impacts on tropical aquatic ecosystems than those already observed in the temperate zone.     

Gross mismatch between thermal tolerances and environmental temperatures in a tropical freshwater snail: Climate warming and evolutionary implications

The relationship between acute thermal tolerance and habitat temperature in ectotherm animals informs about their thermal adaptation and is used to assess thermal safety margins and sensitivity to climate warming. We studied this relationship in an equatorial freshwater snail (Clea nigricans), belonging to a predominantly marine gastropod lineage (Neogastropoda, Buccinidae). We found that tolerance of heating and cooling exceeded average daily maximum and minimum temperatures, by roughly 20 °C in each case. Because habitat temperature is generally assumed to be the main selective factor acting on the fundamental thermal niche, the discordance between thermal tolerance and environmental temperature implies trait conservation following ‘in situ’ environmental change, or following novel colonisation of a thermally less-variable habitat. Whereas heat tolerance could relate to an historical association with the thermally variable and extreme marine intertidal fringe zone, cold tolerance could associate with either an ancestral life at higher latitudes, or represent adaptation to cooler, higher-altitudinal, tropical lotic systems. The broad upper thermal safety margin (difference between heat tolerance and maximum environmental temperature) observed in this snail is grossly incompatible with the very narrow safety margins typically found in most terrestrial tropical ectotherms (insects and lizards), and hence with the emerging prediction that tropical ectotherms, are especially vulnerable to environmental warming. A more comprehensive understanding of climatic vulnerability of animal ectotherms thus requires greater consideration of taxonomic diversity, ecological transition and evolutionary history.