Montane Zone Research Articles

Xylem embolism induced by freeze-thaw and drought are influenced by different anatomical traits in subtropical montane evergreen angiosperm trees.

Subtropical evergreen broadleaved forests distributed in montane zones of southern China experience seasonal droughts and winter frost. Previously, studies have recognized that xylem anatomy is a determinant of its vulnerability to embolism caused by drought and freezing events. We hypothesized that there is a coordination of xylem resistance to freeze-thaw and drought-induced embolism for the subtropical montane evergreen broadleaved tree species because they are influenced by common xylem structural traits (e.g., vessel diameter). We examined the branch xylem anatomy, resistance to drought-induced embolism (P50), and the percent loss of branch hydraulic conductivity after a severe winter frost (PLCwinter) for 15 evergreen broadleaved tree species in a montane forest in South China. Our results showed that P50 of the studied species ranged from -2.81 to -5.13 MPa, which was not associated with most xylem anatomical properties except for the axial parenchyma-to-vessel connectivity. These tree species differed substantially in PLCwinter, ranging from 0% to 76.41%. PLCwinter was positively related to vessel diameter and negatively related to vessel density, vessel group index, and vessel-to-vessel connectivity, but no coordination with P50. This study suggests that hydraulic adaptation to frost is important to determine the distributional limit of subtropical montane evergreen woody angiosperms.

The Effect of Climate on Strongly Disturbed Vegetation of Bait Sites in a Central European Lower Montane Zone, Hungary

Human landscape-transforming activities contribute to the global change in vegetation in different forms. Hunting is one of the most ancient human landscape-shaping activities. Feeders for hunting are particularly disruptive to vegetation. In the present study, we conducted a vegetation survey in these highly disturbed places. We investigated the vegetation dynamics over several years in the turkey oak–sessile oak zone, in two areas with different moisture and shade conditions (forest and clearing). Important background factors are the changes in precipitation and temperature. Our results confirm that weed infestation is detectable at bait sites over a long period. The seasonal changes in field weed vegetation, as well as the increase in the number and coverage of weed species at the end of summer, resulting from lifestyle characteristics, were generally detectable in all years and locations, especially in the case of open and more strongly degraded clearings. Meteorological factors played a role in the degree of weed infestation in each year. Degradation was more significant in drought years, while regeneration was also observed in wetter periods. At baits located in the clearing, we showed a positive correlation between the amount of summer precipitation and the total coverage of weed species, as well as between the average spring temperature and the coverage of certain weed species. With the drying of the climate, the disturbed areas are constantly losing their natural value, but wetter weather is not an automatic solution either. Considering that there are approx. 30,000 bait sites in the country, and they are used regularly and very intensively, they can serve as major infection hotspots for alien species in a network.

Leaf nutrient-based processes of conservatism and convergence regulate the vertical stratification of plant growth forms during subtropical forest degradation

Unveiling the ecological and evolutionary mechanisms that guide the differentiation of various plant growth forms into vertical forest strata during forest degradation continues to pose a challenge. We utilized the biogeochemical niche theory to decipher these mechanisms. We measured leaf concentrations of basal elements (C, N, P, K, Ca, and Mg) and used them to generate the biogeochemical niches in herbs, shrubs, trees, and climbers from different vertical strata within a degraded forest and its neighboring mature forest in subtropical montane zones. Our results showed that biogeochemical niches varied significantly among growth forms. Biogeochemical niches also differed significantly between species in the degraded and mature forests, as evidenced by the significantly lower leaf C concentration relative to other nutrients in degraded forest species. This could be attributable mainly to the expansive canopy openness in the degraded forest, facilitating the colonization of light-demanding self-supporters and climbers. The phylogenetic signals in leaf nutrient concentrations were significantly present across all species, suggesting the general similarities in biogeochemical niches among closely related species. Following evolutionary model comparisons, stabilizing selection towards varying optimal leaf nutrient concentrations for distinct growth forms in the degraded or mature forest emerged as the most suitable model. Our study thus highlights the important role of phylogenetic biogeochemical niche conservatism and stabilizing selection towards various optimal leaf nutrient compositions for diverse growth forms in both degraded and mature forests in the formation of vertical plant communities during subtropical forest degradation.

Pedogenic controls of soil organic carbon stocks and stability beneath montane Norway spruce forests along a precipitation gradient

Reliable data on SOC stocks in forest soils is required in the context of climate change and soil health assessments but still limited by input data availability (e.g., bulk density) and methods used for stock calculation. Relatively few studies have investigated the stability of SOC in forest soils. We investigated SOC stocks and fractionation in soils beneath Norway spruce forests and grasslands in the montane zone along a gradient of mean annual precipitation (MAP). We sampled soil cores volumetrically to 40 cm depth and measured SOC in the fractions <2 mm (fine earth), >200 μm and 200–20 μm (coarse and fine POM), and <20 μm (MAOM) along with potential pedogenic controls. Total SOC stocks beneath forests in the study region, calculated by the equivalent soil mass (ESM) approach to 40 cm depth, amount to 79.0 ± 29.9 (mean ± standard deviation) Mg ha−1 (n = 20) in the mineral soil, and to 92.9 ± 30.6 Mg ha−1 including the litter layer, with a share of 55 % associated with POM. MAOM makes up ∼41 % of SOC in the uppermost mineral layer (0–5 cm) and increases to 71 % in the subsoil (20–40 cm). Multiple regression models show that MAOM is largely controlled by ammonium oxalate extractable Al (Alo) in the forest subsoils (20–40 cm), and increases with MAP in the topsoil layers (0–20 cm). Soils on carbonate rock stand out with ∼80–100 % larger shares of MAOM in the uppermost soil layers (0–10 cm) which is likely connected to higher soil pH and MAP, supporting microbial transformation and subsequent stabilisation of organic matter, which is reflected in narrower C:N ratios in MAOM and SOC.Including the litter layers, ESM-based total SOC stocks in forest soils tend to exceed those beneath grassland (80.2 ± 21.9 Mg ha−1; n = 31) by 16 %, but only by 6.4 % if calculated by the conventional fixed-depth (FD) approach. In contrast to the forest soils, SOC stocks beneath grasslands are dominated by MAOM (75.6 %).We conclude that (coniferous) forest soils are a poor reference for establishing sequestration potentials for stable SOC. The observed large proportion of POM in forest topsoils and its increase with declining MAP (indicating water availability) suggests a risk of SOC losses in response to increasing droughts due to climate change.

Drivers of functional and phylogenetic structures of mountain bird assemblages along an altitudinal gradient from the montane to alpine zones

Understanding the process underlying the spatial gradients in biodiversity is a fundamental issue in ecology. Altitudinal gradients are ideal systems for examining the community assembly process because they represent rapid changes in environmental conditions over relatively short distances. The functional and phylogenetic approaches allow a deeper mechanistic understanding of the underlying assembly process. However, whether community assembly from montane to alpine zones is driven more by ecological constraints or human settlement patterns is not fully resolved and may vary by system. Here, we examined the phylogenetic and trait-based functional structures from the montane to alpine zones and clarified the effects of natural environmental factors and human-induced landscape transformation on the breeding bird assemblage on Mount Norikura, central Japan. Breeding birds from 700 to 3026 m a.s.l. were surveyed in 2016–2017. Bird community structures were examined based on species richness, functional and phylogenetic structures. A null modelling approach was performed to examine functional and phylogenetic cluster/overdispersion structures; clustering and overdispersion imply species elimination by environmental filters and limiting similarity as a corollary of competitive exclusion of species, respectively. Furthermore, we examined the relative effect of natural environments and human disturbance. Bird species richness was high in the mountain base to mid-elevation, then decreased with elevation. We found a contrasting pattern in the phylogenetic and functional structures in the alpine zone: phylogenetic overdispersion and functional clustering. In contrast, the functional and phylogenetic structures were clustered in the upper parts of the subalpine zone. The functional and phylogenetic clusterings in the lower parts of the subalpine and montane zones were negligible with the weak effects of the environmental filtering. Single-trait analysis showed that the high abiotic tolerance and foraging or nesting capabilities in treeless environments were clustered in the alpine zone, and mobility was clustered in the subalpine zones. Natural environments strongly affected bird community structures, but human disturbance added species to assemblages in the mountain base to mid-elevation and changed the functional and phylogenetic structures. Our findings highlight that filtering by severe natural environments is a fundamental community assembly process in high mountain regions, whereas filtering effects can be weaker at lower elevations. Furthermore, the filtering effect should differ between the alpine and the upper parts of the subalpine zones because of different combinations of clustered traits. Climate change and landscape transformation pressures may strongly impact biodiversity in the alpine and subalpine zones, respectively.

Acidophilous grasslands in the Locarnese region (Southern Switzerland): description and classification of main plant communities

This paper presents a phytosociological study of dry and mesophilous meadows and pastures in the Locarnese region (Insubria - Southern Switzerland). Seventy-one vegetation relevés were analysed using both hierarchical classification and nonmetric multidimensional scaling (NMDS) ordination. Seven main clusters were identified and described as follows: (i) xerophytic grasslands on sandy soil dominated by Koeleria macrantha; (ii) mesophilous meadows with Arrhenatherum elatius and Centaurea transalpina; (iii) semi-dry meadows with Chrysopogon gryllus; (iv) semi-dry grasslands with Carex fritschii and Thalictrum minus; (v) nutrient-poor Phyteuma betonicifolium-Festuca nigrescens montane zone grasslands; Nardus stricta grasslands dominated by (vi) Festuca paniculata or (vii) Carex pilulifera. From a phytosociological point of view, a new association named Phyteumo betonicifolii-Festucetum nigrescentis, classified into the Nardo strictae-Agrostion tenuis alliance was proposed. In addition, we confirmed the presence of the Holco-Chrysopogonetum grylli association, within the Bromion erecti, which up to now was provisional only.

The influence of slope exposure and altitude on the height of trees in the stands of the Carpathian beech forest Dentario glandulosae-Fagetum in the lower montane zone in the Bieszczady National Park

The influence of slope exposure and altitude on the height of trees in the stands of the Carpathian beech forest Dentario glandulosae-Fagetum in the lower montane zone in the Bieszczady National Park. The aim of the study was to investigate the influence of slope exposure and elevation above sea level on the average height of trees in the stands of the Carpathian beech forest Dentario Glandulosae-Fagetum in the lower montane zone of the Bieszczady National Park. The research material consisted of measurements made as part of a grid of permanent research plots of the Bieszczady National Park with a size of 4 ares, arranged in a grid of squares with a spacing of 500 x 500 m. Using a two-factor analysis of variance, the average height of beech trees in two height zones (600-800 and 800-1000 m above sea level) and at two slope exposures (north and south) were compared. The influence of the interaction between the two factors was also studied. The height of beech stands was mainly determined by the altitude and the interaction between the exposure of the slope and the altitude. It was not found that the exposure of the slope significantly differentiated the average heights of beech trees in the lower montane zone in the Bieszczady National Park.

Distribution Pattern of Pasang Species (Quercus sundaica Blume) in Mount Slamet Forest, East Banyumas Forest Management Unit

Quercus sundaica (Q. sundaica), commonly known as Pasang, is a Fagaceae family member with a significant ecological and economic contribution to Indonesia. This research aimed to examine the abundance, distribution pattern, and physical growth environment of Q. sundaica. The data collection occurred in KRB (Baturraden Botanical Garden) and P7 (Pancuran 7) in the montane and sub-montane zones. The data analysis included vegetation and soil analysis. The KRB track in the montane zone had the highest Importance Value Index (IVI) with a higher density than the KP7 track.

Factors Limiting Radial Growth of Conifers on Their Semiarid Borders across Kazakhstan.

The forests of Central Asia are biodiversity hotspots at risk from rapid climate change, but they are understudied in terms of the climate-growth relationships of trees. This classical dendroclimatic case study was performed for six conifer forest stands near their semiarid boundaries across Kazakhstan: (1-3) Pinus sylvestris L., temperate forest steppes; (4-5) Picea schrenkiana Fisch. & C.A. Mey, foothills, the Western Tien Shan, southeast; (6) Juniperus seravschanica Kom., montane zone, the Western Tien Shan, southern subtropics. Due to large distances, correlations between local tree-ring width (TRW) chronologies are significant only within species (pine, 0.19-0.50; spruce, 0.55). The most stable climatic response is negative correlations of TRW with maximum temperatures of the previous (from -0.37 to -0.50) and current (from -0.17 to -0.44) growing season. The strength of the positive response to annual precipitation (0.10-0.48) and Standardized Precipitation Evapotranspiration Index (0.15-0.49) depends on local aridity. The timeframe of climatic responses shifts to earlier months north-to-south. For years with maximum and minimum TRW, differences in seasonal maximal temperatures (by ~1-3 °C) and precipitation (by ~12-83%) were also found. Heat stress being the primary factor limiting conifer growth across Kazakhstan, we suggest experiments there on heat protection measures in plantations and for urban trees, alongside broadening the coverage of the dendroclimatic net with accents on the impact of habitat conditions and climate-induced long-term growth dynamics.

Effects of land-use change and disturbance on the fine root biomass, dynamics, morphology, and related C and N fluxes to the soil of forest ecosystems at different elevations at Mt. Kilimanjaro (Tanzania)

Tropical forests are threatened by anthropogenic activities such as conversion into agricultural land, logging and fires. Land-use change and disturbance affect ecosystems not only aboveground, but also belowground including the ecosystems' carbon and nitrogen cycle. We studied the impact of different types of land-use change (intensive and traditional agroforestry, logging) and disturbance by fire on fine root biomass, dynamics, morphology, and related C and N fluxes to the soil via fine root litter across different ecosystems at different elevational zones at Mt. Kilimanjaro (Tanzania). We found a decrease in fine root biomass (80–90%), production (50%), and C and N fluxes to the soil via fine root litter (60–80%) at all elevation zones. The traditional agroforestry 'Chagga homegardens' (lower montane zone) showed enhanced fine root turnover rates, higher values of acquisitive root morphological traits, but similar stand fine root production, C and N fluxes compared to the natural forest. The decrease of C and N fluxes with forest disturbance was particularly strong at the upper montane zone (60 and 80% decrease, respectively), where several patches of Podocarpus forest had been disturbed by fire in the previous years. We conclude that changes on species composition, stand structure and land management practices resulting from land-use change and disturbance have a strong impact on the fine root system, modifying fine root biomass, production and the C and N supply to the soil from fine root litter, which strongly affects the ecosystems' C and N cycle in those East African tropical forest ecosystems.

Understory epiphytic pteridophytes along altitudinal gradients on opposite slopes in the Atlantic Forest

Abstract Gradual climatic changes caused by mountains’ altitudinal variation promote alterations in the structure of ecological communities. Environmental changes are also expected according to the slope’s position in relation to the sea. In this study, we aimed to compare epiphytic pteridophyte communities along altitudinal gradients on opposite slopes in a section of the Atlantic Forest. We sampled a total of 10 sites in the montane and upper montane zones from the eastern (facing the sea) and western (facing away from the sea) slopes. A total of 1,742 individuals from 62 epiphytic species were recorded. The slopes showed similar epiphytic abundances and richness. Species richness showed a tendency to decrease with an increase in altitude on the western slope, and abundance was higher at intermediate altitudes, with no altitudinal trend in dominance. Conversely, on the eastern slope, there was no clear altitudinal pattern in richness or abundance; however, dominance increased with an increase in altitude from 1,200 to 1,800 m. Species compositions differed among altitudinal zones and between slopes. The eastern slope had lower species richness and no clear altitudinal gradient, although it was better preserved than the western one. Thus, there are differences in the community structure of epiphytic pteridophytes from the forest understory due to altitudinal variation and slope orientation, and these findings corroborate our hypotheses.

Changes in the Vegetation, Soil Seed Bank and Soil Properties at Bait Sites in a Protected Area of the Central European Lower Montane Zone

Feeding places for shooting wild boar (so-called bait sites) are spreading in some regions and they have a growing impact on natural ecosystems. Bait sites were investigated to detect the changes in vegetation, the soil seed bank and soil nutrients. The study area is situated in the Mátra Landscape Protection Area, representing a typical oak forest in the Central European lower montane zone (in Hungary). Two types of bait sites were selected: forests and clearings. A vegetation survey, a soil seed bank experiment and a soil analysis were conducted. The degree of degradation of vegetation was similar at the various bait sites, but only the abundance of weeds was higher in the clearings. The density of weed seeds in the soil varied regardless of type, clearly showing the effects of artificial seed sources. The number of weed species was, however, significantly higher in the clearings. The degree of Jaccard-similarity between the vegetation and the seed bank was the highest in the clearings. The dominance of long-term persistent seeds did not differ among bait sites, indicating frequent disturbances at these sites. The amount of soil nutrients was significantly (more than 10 times) higher in the clearings and this, along with their greater openness, may be responsible for the higher number of weed species in their seed banks. The vegetation and the soil of the clearings proved to be more degraded, mainly due to their habitat characteristics, but the seed bank was similarly infected in the less weedy forests; thus, all bait sites may equally be the focal points of a possible invasion. It means new challenges for the management, considering that climate change and the intensive logging and hunting activities can strengthen the effects of bait sites.

​Performance of Garlic Genotypes under Sub montane Zone of Maharashtra

Background: Knowledge about the morphological characteristics of garlic genotypes is most important for selection of the appropriate varieties for appropriate place and achievement of high yields. Besides, characterization is an important aspect for documentation of the performance of the studied cultivars, which subsequently helps for introduction, selection and improvement in existing varieties of garlic. Methods: The experimental material was comprised of 16 genotypes of garlic viz., Phule Baswant, Phule Nilima, Kalwan Local, DN-49-395, DN-49-364, Marwar Local, G-284, G-222, G-444, G-41, G-119, G-215, G-752, G-546, Satara Local and Dahiwadi Local. The collected genotypes of garlic was dibbled on flat beds of 1.5 m × 1.0 m dimensions at a spacing of 15 × 10 cm in randomized block design with three replications and a total plot size of 72.00 m2. The soil selected for present investigation was of medium texture and rich in organic matter. FYM was applied @ 25 t/ha at the time of land preparation and recommended dose of fertilizers i.e. 100:50:50 kg N:P2O5:K2O/ha was applied. The observations on growth parameters at harvest, yield attributes, incidence of pests and diseases, physiological loss in weight (%) and decay percentage at the end of 90 days of storage at ambient temperature were recorded. Result: The data revealed that, the genotypes viz., Phule Nilima, Phule Baswant and G-41 had recorded the better performance with respect to growth and yield attributes with minimum disease and pest incidence and least physiological loss in weight and decay at the end of 90 days of storage at ambient temperature.

The thermal niche and phylogenetic assembly of evergreen tree metacommunities in a mid-to-upper tropical montane zone.

Frost and freezing temperatures have posed an obstacle to tropical woody evergreen plants over evolutionary time scales. Thus, along tropical elevation gradients, frost may influence woody plant community structure by filtering out lowland tropical clades and allowing extra-tropical lineages to establish at higher elevations. Here we assess the extent to which frost and freezing temperatures influence the taxonomic and phylogenetic structure of naturally patchy evergreen forests (locally known as shola) along a mid-upper montane elevation gradient in the Western Ghats, India. Specifically, we examine the role of large-scale macroclimate and factors affecting local microclimates, including shola patch size and distance from shola edge, in driving shola metacommunity structure. We find that the shola metacommunity shows phylogenetic overdispersion with elevation, with greater representation of extra-tropical lineages above 2000 m, and marked turnover in taxonomic composition of shola woody communities near the frost-affected forest edge above 2000 m, from those below 2000 m. Both minimum winter temperature and patch size were equally important in determining metacommunity structure, with plots inside very large sholas dominated by older tropical lineages, with many endemics. Phylogenetic overdispersion in the upper montane shola metacommunity thus resulted from tropical lineages persisting in the interiors of large closed frost-free sholas, where their regeneration niche has been preserved over time.

Assessment of weed invasion at bait sites in a Central European lower montane zone

The effects of wild game feeding on the local environment have been widely investigated in northern European countries but have received little consideration in Central Europe. Bait sites, that is, places where food is set out to entice wild boar for hunting are becoming ever more widespread, and they are having an increasing impact on surrounding vegetation. The aim of the present study was to assess the extent of weed invasion at different bait types. 3 bait sites located in forests, 3 baits in clearings and 3 baits on unpaved forest roads in the Central European lower montane zone, in Hungary. The field work was conducted in May and August. Four transects were laid out (at right angles to each other) from the centre of each bait, and consisted of 22 one meter square quadrats, in which vegetation survey were conducted. The application of multivariate statistical methods (PCA) and UPGMA analysis to the data collected revealed substantial differences between the bait types. The baits in the forest were the least degraded, with a sparse understory cover in both surveys. Road baits displayed a notable difference, as they varied depending on canopy closure, accessibility and exposure. Sites in clearings proved to be the most infected. Furthermore, there was a significant difference between the vegetation of the periods examined, arable weeds dominated in August. A stress gradient was detected along the transects, with the proportion of weeds decreasing from the centre, while the natural components of the vegetation increased. The effect was more noticeable in clearings, probably due to their greater openness. Invasion is typically limited to the immediate environment of the bait sites, but valuable patches of habitat can also be destroyed, and bait sites may serve as bridgeheads for biological invasions.

Wildfire Catalyzed Shift from Conifer to Aspen Dominance in Montane Zone, Colorado

Wildfire Catalyzed Shift from Conifer to Aspen Dominance in Montane Zone, Colorado

Legacies of past human activities on one of the largest old-growth forests in the south-east European mountains

The Dinaric Mountains are a region considered as a hotspot for late-successional montane mixed Abies alba-Fagus sylvatica-Picea abies old-growth forests. This is likely due to historical deforestation levels being presumably lower than in other European regions. This paper provides new insights into the long-term vegetation dynamics and possible legacies of past human activities in old-growth forests in the montane zone of the Dinaric Mountains. Our extensive ground survey and the detailed land-cover types map show that the mixed A. alba-F. sylvatica old-growth forest with sparse P. abies is surrounded by almost pure F. sylvatica stands at Biogradska Gora. The well-dated stand-scale palaeoecological records (pollen, spores, stomata, macrofossils, macroscopic charcoal, and magnetic susceptibility) show that land use (cereal crop cultivation, cattle herding, and fire) during the Middle Ages caused a reduction of the A. alba and P. abies-dominated forest. After a major land abandonment around the Black Death pandemic (mid-14th century) and weaker land-use phases, F. sylvatica-dominated stands developed in the more accessible areas surrounding the old-growth forest. The legacy of past land uses is still visible as the almost pure F. sylvatica stands show less old-growth characteristics than other European beech-dominated old-growth forests. Markedly in contrast to decreasing tree cover elsewhere in the region, tree cover increased several centuries before the formal protection of the forest (1878 ce). These results support the view that historical land-use pressures played an important role for the small extent and the continuity of disturbance-sensitive A. alba and P. abies-dominated old-growth forest stands.

Niche dynamics of Memecylon in Sri Lanka: Distribution patterns, climate change effects, and conservation priorities.

Recent climate projections have shown that the distribution of organisms in island biotas is highly affected by climate change. Here, we present the result of the analysis of niche dynamics of a plant group, Memecylon, in Sri Lanka, an island, using species occurrences and climate data. We aim to determine which climate variables explain current distribution, model how climate change impacts the availability of suitable habitat for Memecylon, and determine conservation priority areas for Sri Lankan Memecylon. We used georeferenced occurrence data of Sri Lankan Memecylon to develop ecological niche models and assess both current and future potential distributions under six climate change scenarios in 2041–2060 and 2061–2080. We also overlaid land cover and protected area maps and performed a gap analysis to understand the impacts of land‐cover changes on Memecylon distributions and propose new areas for conservation. Differences among suitable habitats of Memecylon were found to be related to patterns of endemism. Under varying future climate scenarios, endemic groups were predicted to experience habitat shifts, gains, or losses. The narrow endemic Memecylon restricted to the montane zone were predicted to be the most impacted by climate change. Projections also indicated that changes in species’ habitats can be expected as early as 2041–2060. Gap analysis showed that while narrow endemic categories are considerably protected as demonstrated by their overlap with protected areas, more conservation efforts in Sri Lankan forests containing wide endemic and nonendemic Memecylon are needed. This research helped clarify general patterns of responses of Sri Lankan Memecylon to global climate change. Data from this study are useful for designing measures aimed at filling the gaps in forest conservation on this island.

Distribution, Habitat Associations and Conservation Status of the Sri Lanka Frogmouth Batrachostomus moniliger

Ecological responses of nocturnal predatory birds to forest cover and other geospatial predictors vary both geographically and taxonomically. Considerable knowledge gaps exist regarding the habitat associations of the Sri Lanka Frogmouth, a nocturnal bird restricted to Sri Lanka and the Indian Western Ghats. Via a 20-year island-wide survey, we searched for frogmouths in Sri Lanka to determine their habitat associations at both local and landscape scales and developed a habitat suitability model (HSM) to predict both current and future distribution. We confirmed frogmouth presence in 18% of the surveyed sites across all major bioclimatic zones (wet, intermediate, dry, and arid) from lower elevations (11-767m), comprising a broad geographic range. Frogmouth presence was mostly limited to forests (90%) with a few sites in agricultural mosaics. Land protection, altitude and both local and landscape-scale forest cover, as well as forest-cover loss at both spatial scales, were strong predictors of frogmouth presence. According to our HSM, the southwestern lowlands and parts of the intermediate zone contained the most suitable areas for frogmouths despite their smaller extent. Although the dry and intermediate zones contained extensive habitats for frogmouth, these regions were relatively less suitable. The habitat associations and geographic range of this species in Sri Lanka differ from that seen in India through negative associations with altitude and absence from montane zones, absence from degraded or severely disturbed habitats and independence from proximity to waterways. The Sri Lanka Frogmouth is sensitive to anthropogenic disturbances, including historical forest losses. We recommend landscape-scale conservation planning that incorporates both primary and mature persistent secondary forests to ensure the protection of this unique iconic species.—Karunarathna, S., Dayananda, S.K., Gabadage, D., Botejue, M., Madawala, M., Peabotuwage, I., Madurapperuma, B.D., Ranagalage, M., Udayakumara, A. & Surasinghe, T.D. (2022). Distribution, habitat associations and conservation status of the Sri Lanka Frogmouth Batrachostomus moniliger. Ardeola, 69: 75-95.

Aerosol-modulated heat stress in the present and future climate of India

Heat stress is one of the leading natural causes of mortality in India. Aerosols can potentially impact heat stress by modulating the meteorological conditions via radiative feedback. However, a quantitative understanding of such an impact is lacking. Here, using a chemical transport model, Weather Research Forecasting model coupled with chemistry, we show that high aerosol loading in India was able to mask the heat stress (quantified by the wet bulb globe temperature (WBGT)) by 0.3 °C–1.5 °C in 2010 with a regional heterogeneity across the major climate zones in India. However, the cooling effect of aerosol direct radiative forcing is partially compensated by an increase in humidity. To understand the potential impact of air quality improvement (i.e. reducing aerosol load) on heat stress in the future, WBGT was projected for 2030 under two contrasting aerosol emission pathways. We found that heat stress would increase by >0.75 °C in all the climate zones in India except in the montane zone under the RCP4.5 scenario with a bigger margin of increase in the mitigation emission pathway relative to the baseline emission pathway. On the contrary, under the RCP8.5 scenario, heat stress is projected to increase in limited regions, such as the tropical wet and dry, north-eastern part of the humid sub-tropical, tropical wet, and semi-arid climate zone in peninsular India. Our results demonstrate that aerosols modulate heat stress and, therefore, the heat stress projections in India and anywhere else with high aerosol loading should consider aerosol radiative feedback.