Distribution and Attribution of Terrestrial Snow Cover Phenology Changes over the Northern Hemisphere during 2001–2020

Snow cover phenology has exhibited dramatic changes in the past decades. However, the distribution and attribution of the hemispheric scale snow cover phenology anomalies remain unclear. Using satellite-retrieved snow cover products, ground observations, and reanalysis climate variables, this study explored the distribution and attribution of snow onset date, snow end date, and snow duration days over the Northern Hemisphere from 2001 to 2020. The latitudinal and altitudinal distributions of the 20-year averaged snow onset date, snow end date, and snow duration days are well represented by satellite-retrieved snow cover phenology matrixes. The validation results by using 850 ground snow stations demonstrated that satellite-retrieved snow cover phenology matrixes capture the spatial variability of the snow onset date, snow end date, and snow duration days at the 95% significance level during the overlapping period of 2001–2017. Moreover, a delayed snow onset date and an earlier snow end date (1.12 days decade−1, p < 0.05) are detected over the Northern Hemisphere during 2001–2020 based on the satellite-retrieved snow cover phenology matrixes. In addition, the attribution analysis indicated that snow end date dominates snow cover phenology changes and that an increased melting season temperature is the key driving factor of snow end date anomalies over the NH during 2001–2020. These results are helpful in understanding recent snow cover change and can contribute to climate projection studies.

Identification of Subterranean Termite Genus, Reticulitermes (Blattodea: Rhinotermitidae) in Taiwan

Species identification in the genus Reticulitermes is often difficult because of ambiguous morphological characters. Challenges in Reticulitermes spp. recognition have also been encountered in East Asia, including Taiwan. Because of unknown Reticulitermes taxa in Taiwan and the possible origin of alien Reticulitermes kanmonensis Takematsu in Japan and Korea, reexamining Reticulitermes fauna in Taiwan is imperative. To clarify the Reticulitermes fauna in Taiwan, this study applied two mitochondrial genes (cytochrome oxidase subunit II [COII] and 16S rDNA) and morphological characters for species delimitation. Reticulitermes specimens collected from 63 localities across the main and adjacent islands of Taiwan were analyzed. Phylogenetic analyses, morphological comparisons, and ecological traits suggested the existence of three species in Taiwan: Reticulitermes flaviceps (Oshima), R. kanmonensis, and Reticulitermes leptomandibularis Hsia and Fan. Altitudinal distributions among the three Reticulitermes termites tended to differ: R. flaviceps adapted to low hills, but R. kanmonensis and R. leptomandibularis occurred in medium mountainous areas. The combined data, including haplotype diversities and distribution range, suggest that 1) R. flaviceps is an endemic species and only found in Taiwan; 2) R. kanmonensis and R. leptomandibularis are both native species in Taiwan and China; 3) Japanese R. kanmonensis populations originated from southern China and/or Taiwan and that Korean populations were possibly introduced from Japan.

Madicolous Chironomidae from the Brazilian Atlantic Forest: a checklist with notes on altitudinal distributions (Diptera, Insecta)

Thin layers of water running over rocky surfaces are characteristic of madicolous habitats, which harbor a peculiar Chironomidae community. However, information on the identity, distribution, and ecology of madicolous chironomids in the Neotropical region are still sparse. The main purpose of this research is to reveal and contribute to the ecology of madicolous Chironomidae species, especially regarding their altitudinal distribution in the Atlantic Forest. Sampling was performed using our own designed emergence traps deployed from 0 to 2700 m a.s.l. in 70 sites in three mountains in southeastern Brazil. Sixty taxa of chironomids were collected and identified, of which only 22 are known to science. Most of the species showed a wider distribution than previously known, both in terms of geographic and altitudinal ranges, while others showed significant association with particular altitudinal bands (as evidenced by the indicator species analysis). Atlantic Forest mountainous regions are known to harbor one of the richest fauna in the world and have been suffering from several types of environmental impacts, including climate change, which will especially affect taxa living in specialized habitats. The narrow range of tolerance to environmental conditions verified for mountain species, and the fact that many of them are rare and endemic, make the conservation efforts in these areas indispensable.

Distribución altitudinal del género Pinus en el oeste de Estados Unidos de América y México

The altitudinal distributions of members of the genus Pinus were studied on mountain ranges in the western United States and Mexico. The community of pines on each mountainside consists of members of three major groupings - long-needled Diploxylon species, short-needled Diploxylon species and Haploxylon species. Long-needled Diploxylon species form a core sequence of altitudinally replacing species over whose distribution are superimposed sequences of members of one of the other two groups. In the northern mountains ranges Haploxylon species formed this second sequence while in the southern ranges short-neddled Diploxylon species assumed this role. Some morphological characteristics of these species were examined and random associations of species pairs generated using these characteristics. The results suggest that resource partitioning between altitudinally associated species does not occur but rather that a successional situatton exists with long-needled Diploxylon species being replaced by either Haploxylon in the norrhern ranges or short-needled Diploxylon species in the southern ranges.

Review and analysis of altitudinal distribution of the Andean anurans in Colombia

In the following work we examine the richness and altitudinal distribution of Colombian Andean anurans trying to emphasize patterns of distribution. We also supply an updated checklist of Andean anurans in Colombia. At present, Colombian harbors about 396 Andean frogs: 153 species in the Cordillera Occidental, 187 species in the Cordillera Central, and 131 species in the Cordillera Oriental. Of these, the Cordillera Oriental presents the higher number and percentage of endemic species. The frequency distribution of altitudinal ranges for Colombian Andean frogs shows that the majority of species have narrow altitudinal ranges, less than 500 m altitude, and only a few species have broad altitudinal distributions. On the other hand, lowland species have broader altitudinal ranges than do highland species. The hypothesis of a wider altitudinal range of highland anurans is therefore not supported. Finally, the averages of the Jaccard similarity indices for the Andean anurans along altitudinal gradients in Colombian are approximately similar to those of other tropical anurans reported by Huey (1978), but notably lower than those of anurans of temperate localities. Thus, these results are in concordance with Janzen's hypothesis (1967) about a broader altitudinal range for temperate species, likely because of their higher thermal tolerance.