Temporal and Spatial Variation of NDVI and Its Driving Factors in Qinling Mountain

Qinling Mountains is the north–south boundary of China’s geography; the vegetation changes are of great significance to the survival of wildlife and the protection of species habitats. Based on Landsat products in the Google Earth Engine (GEE) platform, Pearson’s correlation coefficient method, and classification and regression models, this study analyzed the changes in NDVI (Normalized Difference Vegetation Index) in the Qinling Mountains in the past 38 years and the sensitivity of its driving factors. Finally, residual analysis method and accumulate slope change rate are used to identify the impact of human activities and climate change on NDVI. The research results show the following: (1) The NDVI value in most areas of Qinling Mountains is at a medium-to-high level, and 99.76% of the areas correspond to an increasing trend of NDVI, and the significantly increased area accounts for more than 20%. (2) From 1981 to 2019, the NDVI of the Qinling Mountains increased from 0.63 to 0.78, showing an overall upward trend, and it increased significantly after 2006. (3) Sensitivity analysis results show that the western high-altitude area of Qinling Mountain area dominated by grassland is mainly affected by precipitation. The central and southeastern parts of the Qinling Mountains are significantly affected by temperature, and they are mainly distributed in areas dominated by forest. (4) The contribution rates of climate change and human activities to NDVI are 36.04% and 63.96%, respectively. Among them, the positive impact of human activities on the NDVI of the Qinling Mountains accounted for 99.85% of the area. The area with significant positive effect accounted for 36.49%. The significant negative effect area accounts for only 0.006%, mainly distributed in urban areas and coal mining areas.

The Spatial Pattern of the Upper Limit of Montane Deciduous Broad-Leaved Forests and Its Geographical Interpretation in the East Monsoon Realm of China

Montane deciduous broad-leaved forests (MDB) are mainly distributed in the east monsoon realm of China. The upper limit of MDB significantly varies from mountain to mountain. However, the spatial pattern of the upper limit of MDB and its underlying drivers are still unknown. In this study, we conducted hierarchical multiple regression to quantify the effect of climatic factors, peak elevation, and cold tolerance of dominant species on the geographical distribution of the upper limit of MDB on 75 mountains in the east monsoon realm of China. The results show that: (1) the upper limit of MDB in the east monsoon realm of China, 2800 m, is the highest in Taibai peak of the Qinling mountain ranges, from where it tends to decrease both northward and southward. (2) The upper limit of MDB on the mountains with climatic treeline is mainly affected by climatic factors, the minimum temperature of the coldest month (MinT), and the precipitation seasonality (PS), with an R2 of 0.733. (3) The upper limit of MDB on both temperate and subtropical mountains without climatic treeline is affected by MinT, PS, peak elevation, and cold tolerance of dominant species together, with an R2 of 0.793 and 0.748, respectively. (4) The dominant species of the upper limit of MDB significantly differ temperate and subtropical ranges, the former of which is mainly in the genus Betula, and the latter of which is in the genus Quercus. The upper limit of MDB with the genus Fagus as dominant species is only distributed in the mountains towards the south of the Qinling mountain ranges. (5) The warmth index (WI) at the upper limit of deciduous broad-leaved forest on the mountains with climatic treeline is about 60 °C month, which is lower than that at the northernmost boundary of the latitudinal distributed deciduous broad-leaved forest (90 °C month). Our study revealed the spatial pattern and geographical drivers of the upper limit of MDB, improved our understanding of differences in MDB vegetation among different mountain ranges, and provided climatic correlates for predicting the dynamics of the upper limit of MDB under climate change.

Pestalotiopsis abietis sp. nov. from Abies fargesii in China

Pestalotiopsis is a common genus worldwide and causes diseases on many plant hosts. During our investigation on plant diseases in Qinling Mountain in China, Pestalotiopsis species on needles of Abies fargesii was discovered. Based on the phylogeny of combined ITS, TEF and TUB genes, three Pestalotiopsis isolates from present study cluster into a distinct clade close to P. parva in the genus. However, conidia of Pestalotiopsis abietis are obviously larger than those from P. parva. Hence, Pestalotiopsis abietis sp. nov. is introduced herein.

Species Diversity in the Leafhopper Genus Batracomorphus Lewis (Hemiptera: Cicadellidae: Iassinae) from Qinling Mountain in Shaanxi

The genus Batracomorphus Lewis is the third largest leafhopper genus in the world, with its greatest diversity in the Oriental region. Here, nine species of Batracomorphus, including one new species, are recorded from Shaanxi Province, China, for the first time: B. allionii (Turton), B. clavatus Cai and Shen, B. fletcheri Hu and Dai sp. nov., B. geminatus (Li and Wang), B. juno Knight, B. lateprocessus Li and Wang, B. lunatus Cai and He, B. subfuscus (Li and Wang) and B. pandarus Knight. Among them, B. juno Knight is recorded from China for the first time. One new synonym is revealed: B.nigromarginattus Cai and Shen, 1999 is a junior synonym of B. subfuscus (Li and Wang, 1993). All taxa are described, and photographs of male genitalia are given based on observations of specimens from Qinling Mountain in Shaanxi of China. A key to the species found in Qinling Mountain of Shaanxi is also provided.

Rediscovery and phylogenetic relationships of the scolopendromorph centipede Mimops orientalis Kraepelin, 1903 (Chilopoda): a monotypic species of Mimopidae endemic to China, for more than one century

Mimops orientalis Kraepelin, 1903 is a monotypic species of Mimopidae endemic to China. The species is known only from a single specimen, the holotype. Little is known about its biology, habitat associations, or phylogenetic relationships. It was rediscovered on Qinling Mountain in Shaanxi and Henan provinces, China, 117 years after its last record. Detailed descriptions and colour photographs of living specimens are provided along with its ecology, updated conservation notes, and data on sexual dimorphism. A genetic analysis (COI, 16S rRNA, and 28S rRNA) was conducted to assess the phylogenetic relationships among Mimopidae, Cryptopidae, Scolopendridae, Scolopocryptopidae, and Plutoniumidae. The results support classifying Mimopidae as a valid family.

Low-frequency divergence of tree-ring d18O variations on both sides of climatic boundary mountain of eastern China since 1980s

<p>The Qinling Mountain is the most important mountain range in eastern China, and is the geographical boundary and the climatic boundary. We investigated tree-ring d18O variations in South and North Slope of the Qinling Mountain, and found that the variations of tree-ring  d18O were significantly correlated over the past two and a half centuries (r=0.641, n=247, p<0.001). And they are negatively correlated with relative humidity and precipitation, and positively correlated with temperature. Compared with the various hydroclimate-related time series in the surrounding area, it is found that both can represent the region's long-term hydroclimate change. The consistent changes in the interannual time scale may be due to the common modulation of ENSO. However, on the decadal time scale, there have been significant divergence between the two tree-ring  d18O series since 1981 and the divergence may be caused by changes in relative humidity at the sampling site, suggesting that in the context of global warming, although the warming range is the same, but the triggered relative humidity changes are not consistent. In addition, changes in PDO may be another cause of low-frequency difference.</p>

Botryosphaeria qinlingensis sp. nov. causing oak frogeye leaf spot in China

During our investigation on plant diseases in Qinling Mountain in China, an oak disease with frogeye leaf spot symptoms was discovered. The associated pathogen was characterised by morphological and molecular approaches and is described here as a new species, Botryosphaeria qinlingensis.