Background: Amphibians are one of the most susceptible groups to climate change as their development occurs in aquatic environments or in microhabitats with high humidity. Accordingly, our primary objective was to investigate the chronic physiological responses seen in early larval to adult stages of Polypedates cruciger (Common hourglass tree frog) to future climate change based on continuous exposure to elevated temperature and elevated CO 2 -induced low water pH. Free-swimming and free-feeding tadpoles were observed until metamorphosis under four experimental treatments; two elevated temperatures, one elevated CO 2 (reduced pH) and a control maintained at ambient temperature (29°C ± 1°C) and CO 2 (pH = 7). Elevated temperature treatments were maintained at 32°C ± 0.5°C and 34°C ± 0.5°C to represent respectively, the future climate scenarios RCP2.6 (Representative Concentration Pathway 2.6, the 'base-case' scenario) and RCP8.5 ('business-as-usual' scenario) according to the 5 th Assessment Report of the IPCC. Elevated CO 2 treatment was maintained within the pH range of 5.5-5.6 representing the range expected between RCP8.5 and RCP2.6. Results: Compared to the control, elevated CO 2 accelerated phenological progression of tadpoles through Gosner stages, thus resulting in lower body size at metamorphosis. Both elevated temperatures significantly delayed the development and reduced the growth of tadpoles. 100% mortality was observed in 34°C treatment before metamorphosis (before Gosner stage 36) while all the tadpoles died after metamorphosis (at Gosner stage 46) in 32°C treatment. Elevated CO 2 increased tadpole activity, in terms of their swimming speed, while both of the elevated temperatures reduced it compared to the control. Catalase activity increased at elevated CO 2 . Ammonia excretion by tadpoles was decreased by elevated CO 2 , but increased under temperature elevation. Both Elevated CO 2 and temperature treatments reduced the white blood cell count and its percentage of thrombocytes. Percentages of lymphocytes, monocytes and neutrophils were increased at 32°C, while lymphocyte percentage and lysozyme activity were increased at elevated CO 2 . Several deformities were observed in tadpoles at elevated temperature and CO 2 .

Arthropods contribute significantly to biodiversity and vegetation provides a habitat and resources for them to survive, exist and propagate. We report a preliminary investigation on the extent to which arthropod diversity is dependent upon vegetation diversity across different ecosystems in a humid tropical climate. We determined the diversity of arthropods in four ecosystems closely-located ecosystems with different vegetation. Vegetation surrounding an aquatic environment (AQ), a broad-leaved wet, evergreen forest ecosystem (BL), a Pinus caribaea monoculture plantation (PN) and a Pinus plantation artificially enriched with indigenous broad-leaved tree species (PNEN) located in the Hanthana mountain range in Central Sri Lanka were selected. In each environment, arthropods were sampled in three randomlyselected sites (5 m x 5 m) using four sampling methods. Collected arthropods were identified upto the highest possible taxa using standard identification keys. Simultaneously, vegetation diversity was determined via a plant census. Arthropod and vegetation diversities were computed separately for each site using Shannon-Wiener Index (H).Within the 300 m 2 area of observation plots, arthropod individuals belonging to 68 species and 43 families were found. AQ had the greatest arthropod diversity (H=2.642), dominated by Olios spp. followed by BL (H=2.444), dominated by three arthropods, namely, a tettigonid species, Oxytate spp. and Psechrus spp. PN had the next highest arthropod diversity (H=1.411), dominated by Dicaldispa spp. The lowest arthropod diversity was found at PNEN (H=1.3500), dominated by an ant species. Contrastingly, PNEN had the highest plant diversity (H=2.614) and PN the lowest (H=0.879). AQ (H=1.810) and BL (H=1.871) had intermediate values.In a regression involving data from AQ, BL and PN, arthropod diversity was linearly dependent on plant diversity (R 2 =0.423) whereas it was not so when PNEN was also included (R 2 =0.008).This finding supports the hypothesis that while higher plant diversity contributes to greater arthropod diversity in ecosystems where human intervention is minimal, artificial enrichment of plant diversity does not necessarily increase arthropod diversity in the short-to medium-term.Further investigations are needed to substantiate these preliminary findings and validate the above hypothesis.

Lichens are composite organisms formed by symbiotic relationships between algae or cyanobacteria and fungi. Apart from their morphological diversity, lichens hold a major significance in ecology because of their role as biological indicators. Lichens are highly sensitive to environmental stresses, such as air pollution and climate change. Accordingly, the objective of this study was to determine the variation of lichen diversity in the Hantana mountain range along an elevation gradient. Five elevations ranging from 512 to 773m above mean sea level (amsl) were selected in the Hantana mountain range, Peradeniya. The tree species selected for surveying lichens was Alstonia macrophylla because of its availability at all elevations. Two trees were selected randomly from each elevation. In each tree, a monitoring quadrate containing five independent 5x5 cm quadrate segments was hung at 1m from ground level. Lichens in quadrate segments were surveyed using a hand lens, and taxonomically identified using standard pictorial keys. The area of each lichen was measured using ImageJ software (Version 1:51k). In each tree trunk, four sides facing the four directions (North, East, West, and South) were surveyed independently. The Lichen Diversity Values (LDV) and the Indices of Atmospheric Purity (IAP) were calculated for each elevation. With the exception of one site at 583m amsl, the LDV showed a positive exponential relationship (LDV=25.161*e 0.0024*E , R 2 =0.76) with increasing elevation (E). Reduction of air temperature and partial pressure of CO2 (pCO2) with increasing altitude could have contributed to the increasing lichen diversity. The lowermost site (L1) at 512m showed the lowest LDV (95) while the uppermost site (L5) at 773m showed the highest LDV (191). In addition to the natural variation of pCO2, proximity to roads with frequent vehicular traffic could have influenced the observed variation of LDV with elevation. The site at 583m, which did not fit in to the positive exponential relationship, had a higher LDV value (187) than that predicted from the relationship (102) probably because it was the least exposed to vehicular traffic. At all elevations, IAP values were greater than 50, which indicated that they have very low air pollution, indicating the importance of conservation programs. However, the presence of highly sensitive lichen genera such as Physica and Leptotrema being limited only to sites at upper elevations indicate that those sites are less polluted. On the other hand, lichen genera Megalospora, Graphis and Wirthiotrema were observed at all elevations.