Responses to recent climatewarming of Pinus sylvestris and Pinus cembra within their montane transition zone in the Swiss Alps

Abstract. Altitudinal and latitudinal distribution limits of trees are mainly controlled by temperature. Therefore climate warming is expected to induce upslope or poleward migrations. In the Swiss Central Alps, summers in the period 1982-1991 were on average 0.8 °C warmer than those of the period 30 yr before. We investigated whether populations of conifers at the montane Pinus sylvestris-Pinus cembra ecocline exhibit demographic trends in response to that warming. We found no evidence for this. Young seedlings of Pinus sylvestris, the species which is expected to expand its range upward in a warmer climate, were virtually absent from all sites, whereas large fractions of Pinus cembra populations were observed in the seedling and juvenile categories even below the present lower distribution limit of adult trees. This suggests that there are no major altitudinal shifts in response to the recent sequence of warmer summers. Germination and seedling survival trials with Pinus sylvestris suggest that temperature per se would not exclude this species even from establishing at the current treeline in the Swiss Central Alps. Similar results were found at the polar treeline. Phytotron tests of seedling survival showed much less drought resistance in Pinus sylvestris than in Pinus cembra which is in contrast to their phytogeographic distributions. Thus, the montane pine ecocline in the Swiss Central Alps seems to be stabilized by species interactions and may not be directly responsive to moderate climatic change, which needs to be taken into account in predictive attempts.     

Contrasting growth forecasts across the geographical range of Scots pine due to altitudinal and latitudinal differences in climatic sensitivity

Ongoing changes in global climate are altering ecological conditions for many species. The consequences of such changes are typically most evident at the edge of a species’ geographical distribution, where differences in growth or population dynamics may result in range expansions or contractions. Understanding population responses to different climatic drivers along wide latitudinal and altitudinal gradients is necessary in order to gain a better understanding of plant responses to ongoing increases in global temperature and drought severity. We selected Scots pine (Pinus sylvestris L.) as a model species to explore growth responses to climatic variability (seasonal temperature and precipitation) over the last century through dendrochronological methods. We developed linear models based on age, climate and previous growth to forecast growth trends up to year 2100 using climatic predictions. Populations were located at the treeline across a latitudinal gradient covering the northern, central and southernmost populations and across an altitudinal gradient at the southern edge of the distribution (treeline, medium and lower elevations). Radial growth was maximal at medium altitude and treeline of the southernmost populations. Temperature was the main factor controlling growth variability along the gradients, although the timing and strength of climatic variables affecting growth shifted with latitude and altitude. Predictive models forecast a general increase in Scots pine growth at treeline across the latitudinal distribution, with southern populations increasing growth up to year 2050, when it stabilizes. The highest responsiveness appeared at central latitude, and moderate growth increase is projected at the northern limit. Contrastingly, the model forecasted growth declines at lowland‐southern populations, suggesting an upslope range displacement over the coming decades. Our results give insight into the geographical responses of tree species to climate change and demonstrate the importance of incorporating biogeographical variability into predictive models for an accurate prediction of species dynamics as climate changes.     

Formation mechanisms of the alpine Erman’s birch (Betula ermanii) treeline on Changbai Mountain in Northeast China

Key message

The treeline on Changbai Mountain controlled by low temperature and water stress, has not reached the position most commonly expected.

Abstract

Treeline pattern is an important consideration in exploring the general mechanisms controlling the response of treelines to climatic change. However, most of the present conclusions were derived from evergreen and/or conifer treeline, it is still not clear about the deciduous treeline. This study analyzed concentrations of non-structural carbohydrates (NSC) and their components (total soluble sugars and starch) in tree tissues of the deciduous species Erman’s birch (Betula ermanii) at four points along an elevational gradient ranging from 1,908–2,058 m a.s.l at the end of the growing season on Changbai Mountain in Northeast China. The mean 10-cm soil temperature of 8.2 °C under trees across the 129-day growing season at the treeline in this region was higher than that of the average threshold temperature found at treeline positions in the global and China’s climate studies. However, altitudinal trends of NSC concentrations increased significantly in all tissue types along the altitudinal gradients, revealing no depletion of carbon reserves at the treeline on Changbai Mountain. At the same time, the pronounced variation of δ¹³C in leaves and aged branches suggested that low temperature and water stress may simultaneously be operating at high altitudes to restrict the growth and NSC accumulation in trees above the treeline. In light of the above, we conclude that treeline formation on Changbai Mountain is no carbon depletion at the end of growing season, and most likely the result of sink limitation reflecting the combined effects of low temperature and water stress that determined the actual position of the treeline.     

High genetic structure of the Cozumel Harvest mice,a critically endangered island endemic: conservation implications

We assessed the genetic structure and diversity of Reithrodontomys spectabilis, a critically endangered, endemic rodent from Cozumel Island, México. A total of 90 individuals were trapped from September 2001 to January 2005. Microsatellite data analysis revealed high genetic diversity values: a total of 113 alleles (average 12.5 per locus), H _o  = 0.78, H _e  = 0.80. These high values can be related to Cozumel’s size (478 km²) and extensive native vegetation cover, factors that could be promoting a suitable population size, high heterozygosity and the persistence of rare alleles in the species, as well as some long-term movement of individuals between sampling localities. A strong genetic structure was also observed, with at least four genetic groups, associated with a pattern of isolation by distance. We found a strong allelic and genetic differentiation shown between localities, with negligible recent gene flow and low inbreeding coefficients. The species life history and ecological characteristics—being nocturnal, semi-terrestrial, a good tree climber, having lunar phobia and significant edge effect—are likely affecting its genetic structure and differentiation. The high genetic diversity and population structure award R. spectabilis a significant conservation value. Our results can serve as a basis for future research and conservation of the species, particularly considering the problems the island is facing from habitat perturbation, urbanization and introduction of exotic species. In view of the structure and genetic variability observed, it is essential to establish and reinforce protected areas and management programs for the conservation of the endemic and endangered Cozumel Harvest mice.     

Uniform selection as a primary force reducing population genetic differentiation of cavitation resistance across a species range

Background

Cavitation resistance to water stress-induced embolism determines plant survival during drought. This adaptive trait has been described as highly variable in a wide range of tree species, but little is known about the extent of genetic and phenotypic variability within species. This information is essential to our understanding of the evolutionary forces that have shaped this trait, and for evaluation of its inclusion in breeding programs.

Methodology

We assessed cavitation resistance (P ₅₀), growth and carbon isotope composition in six Pinus pinaster populations in a provenance and progeny trial. We estimated the heritability of cavitation resistance and compared the distribution of neutral markers (F _ST) and quantitative genetic differentiation (Q _ST), for retrospective identification of the evolutionary forces acting on these traits.

Results/Discussion

In contrast to growth and carbon isotope composition, no population differentiation was found for cavitation resistance. Heritability was higher than for the other traits, with a low additive genetic variance (h² _ns = 0.43±0.18, CV_A = 4.4%). Q _ST was significantly lower than F _ST, indicating uniform selection for P ₅₀, rather than genetic drift. Putative mechanisms underlying Q_STST are discussed.     

Better up,worse down: bidirectional consequences of three decades of climate change on a relict population of Erebia cassioides

Orophilous species are often unable to escape the consequences of climate change because mountains are surrounded by unsuitable habitats. Among them, several endemic species belonging to the genus Erebia Dalman (Lepidoptera, Nymphalidae, Satyrinae) can be considered as key species to assess the risk of biodiversity loss of mountain habitats. The aim of this paper is to measure changes that have occurred in the altitudinal distribution of Erebia cassioides on the Pollino Massif (Southern Italy) during the last 37 years. Sixteen sites sampled in 1975 have been resampled after about three decades (2004, 2012). In 1975 56 % of the sampled population inhabited sites above and 44 % sites below the treeline, while in 2004 and 2012 99 % of the population were observed above the treeline. Furthermore, we observed an uphill shift of 180 m in the barycentre altitude of the species distribution and an unexpected increased density of the population above the treeline which led to a range reduction coupled to population increase of E. cassioides. This pattern contrasts with the usually observed one that couples habitat reduction to population decreasing. The reason for the observed pattern is unclear, but the implication for conservation strategies could be important if confirmed for other species. In fact, during coming decades local extinctions as a consequence of climate change might be fewer and more delayed than expected, and relict populations of cold adapted species could be preserved for a longer time span within optimal habitat refugia.     

Xylem cavitation vulnerability influences tree species’ habitat preferences in miombo woodlands

Although precipitation plays a central role in structuring Africa’s miombo woodlands, remarkably little is known about plant-water relations in this seasonally dry tropical forest. Therefore, in this study, we investigated xylem vulnerability to cavitation for nine principal tree species of miombo woodlands, which differ in habitat preference and leaf phenology. We measured cavitation vulnerability (Ψ₅₀), stem-area specific hydraulic conductivity (K _S), leaf specific conductivity (K _L), seasonal variation in predawn water potential (Ψ_PD) and xylem anatomical properties [mean vessel diameter, mean hydraulic diameter, mean hydraulic diameter accounting for 95 % flow, and maximum vessel length (V _L)]. Results show that tree species with a narrow habitat range (mesic specialists) were more vulnerable to cavitation than species with a wide habitat range (generalists). Ψ₅₀ for mesic specialists ranged between ?1.5 and ?2.2 MPa and that for generalists between ?2.5 and ?3.6 MPa. While mesic specialists exhibited the lowest seasonal variation in Ψ_PD, generalists displayed significant seasonal variations in Ψ_PD suggesting that the two miombo habitat groups differ in their rooting depth. We observed a strong trade-off between K _S and Ψ₅₀ suggesting that tree hydraulic architecture is one of the decisive factors setting ecological boundaries for principal miombo species. While vessel diameters correlated weakly (P > 0.05) with Ψ₅₀, V _L was positively and significantly correlated with Ψ₅₀. Ψ_PD was significantly correlated with Ψ₅₀ further reinforcing the conclusion that tree hydraulic architecture plays a significant role in species’ habitat preference in miombo woodlands.     

Molecular evidence for glacial expansion and interglacial retreat during Quaternary climatic changes in a montane temperate pine (Pinus kwangtungensis Chun ex Tsiang) in southern China

It has been suggested that the eastern Asian temperate flora have responded to Quaternary climatic changes in a different way compared with temperate plants in Europe and Northern America. However, knowledge about their phylogeographic structure and evolutionary history is still limited. In this study we investigated mitochondrial DNA variation in 17 populations of Pinus kwangtungensis, a five-needled pine inhabiting in isolated mountains of southern China and northern Vietnam. A total of ten mitochondrial haplotypes (mitotypes) were characterized by the polymorphisms of two fragments (cox-1-2 and nad7 intron1), and total genetic diversity was high (h _T = 0.847). The construction of phylogenetic relationships of the ten mitotypes detected three major, well-distinct clades, largely corresponding to four population groups identified by SAMOVA analysis. SAMOVA also indicated that most genetic variance should be attributed to among-group differentiation (F _CT = 0.868), consistent with the substantial genetic structure found within P. kwangtungensis (G _ST = 0.751). The genetic distances of P. kwangtungensis weakly but significantly correlated with geographical distances (R = 0.228, P = 0.03), revealing a pattern of isolation-by-distance. Demographic analysis did not detect any bottleneck events in the recent history of P. kwangtungensis. These results clearly suggested that there were three major refugia for this montane temperate conifer during warm stages (along with other minor refugia), and that the species would have tracked Quaternary climatic changes by expanding to nearby lowlands in the glacial periods, and by retreating to mountaintops (the refugia) during interglacial warmer stages, experiencing fragmentation and isolation among refugia.     

Status of Resistance of <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Hemiptera: Aleyrodidae) to Neonicotinoids in Iran and Detoxification by Cytochrome P450-Dependent Monooxygenases

Nine Bemisia tabaci (Gennadius) populations were collected from different regions of Iran. In all nine populations, only one biotype (B biotype) was detected. Susceptibilities of these populations to imidacloprid and acetamiprid were assayed. The lethal concentration 50 values (LC₅₀) for different populations showed a significant discrepancy in the susceptibility of B. tabaci to imidacloprid (3.76 to 772.06 mg l^?1) and acetamiprid (4.96 to 865 mg l^?1). The resistance ratio of the populations ranged from 9.72 to 205.20 for imidacloprid and 6.38 to 174.57 for acetamiprid. The synergistic effects of piperonylbutoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) were evaluated for the susceptible (RF) and resistant (JR) populations for the determination of the involvement of cytochrome P450-dependent monooxygenase and carboxylesterase, respectively, in their resistance mechanisms. The results showed that PBO overcame the resistance of the JR population to both imidacloprid and acetamiprid, with synergistic ratios of 72.7 and 106.9, respectively. Carboxylesterase, glutathione S-transferase and cytochrome P450-dependent monooxygenase were studied biochemically, for the purpose of measuring the activity of the metabolizing enzymes in order to determine which enzymes are directly involved in neonicotinoid resistance. There was an increase in the activity of cytochrome P450-dependent monooxygenase up to 17-fold in the resistant JR population (RR?=?205.20). The most plausible activity of cytochrome P450-dependent monooxygenase correlated with the resistances of imidacloprid and acetamiprid, and this suggests that cytochrome P450-dependent monooxygenase is the only enzyme system responsible for neonicotinoid resistance in the nine populations of B. tabaci.     

High level of genetic variation within clonal orchid Goodyera repens

Type of reproduction has an important effect on the maintenance of particular populations and species persistence in time and space. This trait significantly influences the ecological and genetic structure of populations, and in consequence the evolution of species. The primary objectives of this study were: to estimate genetic diversity within and among populations of clonal species Goodyera repens from different populations in northeastern Poland, and to amount factors shaping the genetic structure of this orchid. Based on 451 rosettes of G. repens from 11 localities in northeastern Poland, we conducted a genetic population analysis using allozymes. We included information on population size, flowering, fruit set and seed dispersal to elucidate their influences on genetic diversity of this species. Populations differed according to demographic properties. The majority of seeds (86.4–94.8 %) were found at a distance of 0.2 m. We observed a high level of genetic (P _PL = 50 %, A = 1.68, H _O = 0.210, H _E = 0.204) and genotypic diversity (G = 163, G/N _S = 0.66, G _U = 30.2 %), and low but statistically significant genetic differentiation among populations (F _ST = 0.060; P < 0.001). We suggest that the genetic diversity of G. repens is mainly an effect of the abundance of pine and spruce forest communities suitable for this species in NE Poland and the high level of sexual reproduction.     

Chloroplast DNA haplotype diversity and postglacial recolonization of Hagenia abyssinica (Bruce) J.F. Gmel. in Ethiopia

We investigated genetic variation of 273 individuals from 25 populations of the monotypic species Hagenia abyssinica (Rosaceae) from the highlands of Ethiopia at three chloroplast microsatellite loci. The objectives were to infer the factors that shaped the genetic structure and to reconstruct the recolonization history of the species. Six haplotypes that were phylogenetically grouped into two lineages were identified. Homology of the three loci to the respective regions of the chloroplast genome was confirmed by sequencing. The chloroplast haplotypes found in Hagenia showed a clear pattern of congruence between their geographical distribution and genealogical relationships. A very low haplotype diversity within populations (h _S = 0.079, v _S = 0.058) and a very high population differentiation (G _ST = 0.899, N _ST = 0.926) was observed, reflecting very low mixing between recolonizing lineages. Restricted gene flow through seeds, rare long-distance dispersal, contiguous range expansion and mutation shaped the genetic structure of Hagenia. Fossil pollen records suggested that the trend of postglacial recolonization of Hagenia was first in the south and latter went to the north in Ethiopia.     

Genetic Variation in Chinese Pine (Pinus tabulaeformis), a Woody Species Endemic to China

Random amplified polymorphic DNA markers were used to investigate genetic variation of the Chinese pine (Pinus tabulaeformis Carr.), a species endemic to China and the most widely distributed pine species in North China. The results revealed that P. tabulaeformis populations had a relatively high level of genetic diversity (H _t = 0.3268), distributed mainly within (79.2%) rather than among (20.8%) populations. The populations of Lingkong Mountain and Wuling Mountain had a higher level of diversity (0.2687) than the other four populations (0.2537). No statistically significant relationships were found between genetic diversity and climatic factors by correlation analysis and between genetic distance and geographic distance by the Mantel test. These results suggest that the partitioning of genetic diversity in each population might have been influenced not only by water and temperature conditions but also by other factors such as human activities and the Holocene postglacial history of these populations.     

Performance of germinating tree seedlings below and above treeline in the Swiss Alps

The germination and early survival of tree seedlings is a critical process for the understanding of treeline dynamics with ongoing climate change. Here we analyzed the performance of 0–4 year-old seedlings of seven tree species at three sites above and below the current altitudinal treeline in the Swiss Central Alps near Davos. Starting from sown seeds, we monitored the seedling performance as proportions of living seedlings, seedling shoot height growth, and biomass allocation over 4 years to examine changes along an elevational gradient. We evaluated the relative importance of the environmental factors soil temperature, light conditions, water use efficiency, and nitrogen availability on seedling performance. During the 4 years, the proportions of living seedlings differed only slightly along the elevational gradient even in species currently occurring at lower elevations. Microsite-specific soil temperature and light availability had only little effect on the proportion of living seedlings and seedling biomass across the elevational gradient. Conversely, seedling biomass and biomass allocation correlated well with the foliar stable nitrogen isotope abundance (δ ¹⁵N) that was used as an indicator for nitrogen availability. Collectively, our results suggested that the early establishment of seedlings of a variety of tree species in the treeline ecotone was not limited by current climatic conditions even beyond the species’ actual upper distribution limit. Nitrogen dynamics appeared to be an important environmental co-driver for biomass production and allocation in very young tree seedlings.     

High genetic diversity detected in the endemic Primula apennina Widmer (Primulaceae) using ISSR fingerprinting

Primula apennina Widmer is endemic to the North Apennines (Italy). ISSR were used to detect the genetic diversity within and among six populations representative of the species distribution range. High levels of genetic diversity were revealed both at population percentage of polymorphic band (PPB = 75.92%, H _S = 0.204, H _pop = 0.319) and at species level (PPB = 96.95%, H _T = 0.242, H _sp = 0.381). Nei gene diversity statistics (15.7%), Shannon diversity index (16.3%) and AMOVA (14%) detected a moderate level of interpopulation diversity. Principal coordinate and Bayesian analyses clustered the populations in three major groups along a geographic gradient. The correlation between genetic and geographic distances was positive (Mantel test, r = 0.232). All together, these analyses revealed a weak but significant spatial genetic structure in P. apennina, with gene flow acting as a homogenizing force that prevents a stronger differentiation of populations. Conservation measures are suggested based on the observed pattern of genetic variability.     

Phenotypic plasticity in mesic populations of Pinus pinaster improves resistance to xylem embolism (P50) under severe drought

The objectives of the study were to assess the phenotypic variation in the vulnerability to water stress-induced cavitation (estimated by P₅₀, or the xylem water potential which causes a 50% loss of conductivity) and the trade-offs between P₅₀ and related hydraulic traits, i.e., stem specific conductivity (K _s), slope of the vulnerability curve (slope), wood density and branch size. Variability was examined for six Pinus pinaster populations covering the latitudinal range of the species and plasticity was tested through two provenance-progeny trial sites (xeric/mesic). As expected, the overall values of P₅₀, K _s and branch size decreased in the xeric site. Variation in P₅₀ and K _s among populations was mainly the result of phenotypic plasticity, while wood density was genetically controlled and not affected by the environment. Stress conditions in the xeric site promoted a convergence in P₅₀ and K _s as a result of the high phenotypic plasticity of the populations from mesic origins. In the mesic site, the ranking of populations for cavitation resistance and hydraulic capacity was consistent with the geographic location of the seed source. Higher resistance to cavitation was related to lower K _s, branch size and slope, mainly at the population level, but also as a general trend across individuals. In a warmer and drier climate, there could be a potential selection of Pinus pinaster populations from mesic origins, which showed a great responsiveness and adjustment to drought conditions (similar or higher P₅₀ than the populations from dry origins), in addition to a high wood density and growth.     

How far do adult turtles move? Home range and dispersal of Kinosternon integrum

We describe the home range and movements of a population of Kinosternon integrum in Tonatico, Estado de México, México, over 3.5 years (during rainy and dry season months) using radiotelemetry in 37 adult turtles. The results showed that the home range of K. integrum was 0.151 ± 0.051 ha using 50% kernel density estimator (KDE), and 0.657 ± 0.214 ha using 95% KDE; the home range did not vary between sexes. Kinosternon integrum showed low distances traveled 51.44 ± 4.50 m, where 87.3% (n = 373) of movements were <100 m. The distance traveled differed by season, and movement category (aquatic and terrestrial movements). The shortest distance occurred during the dry season, during which some individuals move to estivation sites, and these movements were shorter than movements to artificial ponds (cattle ponds). In this population, home range and movement are similar to other species of the genus Kinosternon. Overall, the results indicate than K. integrum are highly dependent on aquatic habitats, but also utilize the terrestrial habitats for different biological activities, and to maintain viable populations. Therefore, the conservation of the entire inhabited area is fundamental. This study highlights the need to increase the studies, in Central México, concerning habitat use of freshwater turtles in order to increase the efficiency of conservation strategies.     

Pinus georginae (Pinaceae), a new species from western Jalisco, Mexico

Pinus georginae is described and illustrated as a new endemic species from the valleys in the southern basin of Río Ameca, Jalisco, western Mexico. It is closely related to Pinus praetermissa; however, after studying the cones and anatomy of the leaves in detail, characteristics were revealed that identify P. georginae as a distinct species.

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Resumen  Se describe e ilustra Pinus georginae como una especie nueva, endémica de algunos valles intermontanos al sur del Río Ameca, Jalisco, en el Occidente de México. Los árboles se parecen a Pinus praetermissa; sin embargo, al estudiar con detalle los conos y la anatomía de las acículas lo ubican a Pinus georginae como una entidad biológica con categoría específica independiente.

     

MATING SYSTEM AND GENETIC STRUCTURE OF THE DISTYLOUS TROPICAL TREE PSYCHOTRIA FAXLUCENS (RUBIACEAE)

The population genetics and mating system of the understory tropical rain forest tree Psychotria faxlucens were studied at two plots in Los Tuxtlas, Veracruz, México, on the Gulf of México coast. This species is distylous and is pollinated by moths, mainly small hawkmoths. The seeds are dispersed by gravity and by frugivorous birds. Controlled pollinations indicate that the trees are self-incompatible and that intramorph pollinations have lower compatibilities than intermorph pollinations. The pollen: ovule ratio is high, suggesting obligate xenogamy. Using electrophoretic allozyme methods we found that eight out of 20 loci were polymorphic (P = 0.400), the observed heterozygosity (H) was 0.198, and the mean expected heterozygosity (H) was 0.495, both relatively high values compared with that reported for tropical trees. The genetic differentiation between the two plots is low, as shown by the heterogeneity in allele frequencies and the F_st (mean F_st seedlings = 0.031, mean F_st adults = 0.026), although for some loci the plot differentiation is statistically significant. The studied populations are near Hardy-Weinberg proportions, both for seedlings (mean F = 0.128) and adults (mean F = 0.075). From the fixation rate, an indirect estimate of the outcrossing rate at equilibrium gave a mean of t = 0.898 for plot 1 and 0.685 for plot 2. Direct single loci and multiloci outcrossing rate estimates were generally not statistically different from 1.0.     

Isolation by landscape in populations of a prized edible mushroom Tricholoma matsutake

Tricholoma matsutake, a wild edible ectomycorrhizal mushroom, is revered for its distinguished flavor and iconic significance. Here, we test for landscape effects on T. matsutake gene flow and population structure in the Eastern Himalayas. Using single-nucleotide polymorphic (SNP) DNA markers, isolation by distance patterns were tested on eight populations within and between watersheds. We find that high, treeless ridgelines are effective barriers to gene flow, even at distances less than 65 km, whereas populations located within watersheds are structured at greater distances. Mantel tests demonstrated a significant positive correlation between F _st and a “landscape distance” measured as the shortest distance between population pairs below treeline r = 0.574, P = 0.002, whereas strict euclidian distances do not correlate. AMOVA analysis revealed significant partitioning with 91% of the genetic variance found within populations and 7% found between watersheds, indicative of sexually recombining populations with limited gene flow between watersheds. We show that landscape is an important determinant of air-dispersed ectomycorrhizal species population structure in heterogeneous landscapes.     

Influence of developmental temperature on cold shock and chill coma recovery in Drosophila ananassae: Acclimation and latitudinal variations among Indian populations

Exposure of various Drosophila species to mild increase or decrease in temperature has consistently been shown to result in increased resistance to subsequent temperature extremes. We investigated cold tolerance in 45 Indian natural populations of Drosophila ananassae collected from all over India by monitoring the time taken by adults to recover from chill-coma after a treatment for 16 h at 4 °C. Significant latitudinal and altitudinal differentiation was observed for chill coma recovery in D. ananassae. Chill-coma recovery was closely associated with local climatic factors like average annual temperature and relative humidity of origin of populations.