The Spatially Inhomogeneous Influence of Snow on the Radial Growth of Schrenk Spruce (Picea schrenkiana Fisch. et Mey.) in the Ili-Balkhash Basin, Central Asia

Snow has an important impact on forest ecosystems in mountainous areas. In this study, we developed 14 tree-ring-width chronologies of Schrenk spruce (Picea schrenkiana Fisch. et Mey.) for the Ili-Balkhash Basin (IBB), Central Asia. We analyzed the response of radial growth to temperature, precipitation and snow parameters. The results show that previous winter and current summer precipitation have an important influence on the radial growth of P. schrenkiana. Further, we find spatially inhomogeneous effects of snow on subsequent growing-season tree growth in IBB. The radial growth response of P. schrenkiana to snow shows a weak–strong–weak trend from west to east across the Ili-Balkhash Basin. This spatial difference is mainly related to precipitation, as snow has little effect on tree growth in regions that receive more precipitation. Thus, winter snow has an important influence on the radial growth of trees in regions that receive limited amounts of precipitation.

New to Kazakhstan species of zygomycetes in forest soil of Trans-Ili Alatau and Kungey Alatau

This article provides data on two species of soil zygomycetes, new to Kazakhstan, found in the rhizosphere of various woody plants in the Trans-Ili and Kungey Alatau (Northern Tien Shan) – Piptocephalis cylindrospora and Lichtheimia corymbifera. P. cylindrospora is an obligate parasite of zygomycetous fungi; in the study area, it was found twice in Kungey Alatau on species Absidia spinosa and Lichtheimia corymbifera in the rhizosphere of Populus tremula. It does not cause a noticeable deterioration in the development of the host. Earlier, in Kazakhstan, only Piptocephalis arrhiza was registered in the rhizosphere of Armeniaca vulgaris, Populus tremula, Picea schrenkiana, Juniperus spp. Lichtheimia corymbifera, previously belonging to the genus Absidia, was recorded in the rhizosphere of Populus tremula in Kungey Alatau and in the rhizosphere of Picea schrenkiana, Salix sp., Crataegus sp. in Trans-Ili Alatau. L. corymbifera is characterized by heights of 1677 m in Kungey Alatau, and from 1516 to 2007 m a. s. l. in Trans-Ili Alatau. Until recently, in Kazakhstan, only a closely related species Absidia spinosa was isolated from the rhizosphere of Malus sieversii, Armeniaca vulgaris, Crataegus spp., Pinus sylvestris, Populus spp., Sorbus tianschanica, Picea schrenkiana, Salix spp. Descriptions of species colonies based on isolated pure cultures, morphological data, information on ecology and distribution are offered. In L. corymbiferacultures, the so-called “self-parasitism” is observed, in which the fungal hyphae colonize sporangiophores, and the latter look like penetrated by hyphae. The sexual stage of both species was not found in our studies.

Warming Increases the Carbon Sequestration Capacity of Picea schrenkiana in the Tianshan Mountains, China

As an essential part of terrestrial ecosystems, convenient and accurate reconstruction of the past carbon sequestration capacity of forests is critical to assess future trends of aboveground carbon storage and ecosystem carbon cycles. In addition, the relationship between climate change and carbon sequestration of forests has been vigorously debated. In this study, dynamic change of carbon sequestration capacity in aboveground biomass of Picea schrenkiana (hereinafter abbreviated as P. schrenkiana) in the Tianshan Mountains, northwestern China, from 1850–2017, were reconstructed using dendrochronology. The main climate drivers that affected carbon sequestration capacity in aboveground biomass of P. schrenkiana were then investigated. The results showed that: (1) tree-ring width and diameter at breast height (DBH) of P. schrenkiana obtained from different altitudes and ages were an effective and convenient estimation index for reconstructing the carbon sequestration capacity of P. schrenkiana. The carbon storage of P. schrenkiana forest in 2016 in the Tianshan Mountains was 50.08 Tg C calculated using tree-ring width and DBH, which was very close to the value determined by direct field investigation data. (2) The annual carbon sequestration potential capacity of P. schrenkiana exhibited an increasing trend from 1850–2017. Temperature, especially minimum temperature, constituted the key climatic driver resulting in increased carbon sequestration capacity. The contribution rates of temperature and minimum temperature to the change of P. schrenkiana carbon sequestration capacity was 75% and 44%, respectively. (3) The significant increase of winter temperature and minimum temperature led to warming in the Tianshan Mountains, resulting in a significant increase in carbon sequestration capacity of P. schrenkiana. The results indicate that, with the continuous increase of winter temperature and minimum temperature, carbon sequestration of P. schrenkiana in the Tianshan Mountains is predicted to increase markedly in the future. The findings of this study provide a useful basis to evaluate future aboveground carbon storage and carbon cycles in mountain systems possessed similar characteristics of the Tianshan Mountains.

The morphological and chemical properties of fine roots respond to nitrogen addition in a temperate Schrenk’s spruce (Picea schrenkiana) forest

Fine roots (< 2 mm in diameter) play an important role in belowground ecosystem processes, and their physiological ecology is easily altered by nitrogen deposition. To better understand the response of physiological and ecological processes of fine roots to nitrogen deposition, a manipulation experiment was conducted to investigate the effects of exogenous nitrogen addition (control (0 kg ha−1 a−1), low (5 kg ha−1 a−1), moderate (10 kg ha−1 a−1), and high nitrogen (20 kg ha−1 a−1)) on the biomass, morphological characteristics, chemical elements and nonstructural carbohydrates of fine roots in a Picea schrenkiana forest. We found that most fine roots were located in the 0–20 cm of soil layer across all nitrogen treatment groups (42.81–52.09% of the total biomass). Compared with the control, the biomass, specific root length and specific root area of the fine roots increased in the medium nitrogen treatment, whereas the fine roots biomass was lower in the high nitrogen treatment than in the other treatments. In fine roots, nitrogen addition promotes the absorption of nitrogen and phosphorus and their stoichiometric ratio, while reducing the content of nonstructural carbohydrates. The content of nonstructural carbohydrates in the small-diameter roots (< 1 mm in diamter) in each nitrogen treatment group was lower than that in the large-diameter roots. Correlation analysis showed that soil carbon and nitrogen were positively correlated with fine root biomass and specific root length and negatively correlated with the nonstructural carbohydrates. Our findings demonstrate that medium nitrogen addition is conducive to the development of fine root morphology, while excessive nitrogen can suppress the growth of root systems.

Revision of the Species Composition of Slime Molds in the Ile Alatau (Kazakhstan)

After the revision, it was found that the biota of slime molds in the Ile Alatau (Kazakhstan) has 62 species. The article provides a systematic list of slime molds. In the Ile Alatau these fungi-like organisms are represented by two classes: Protosteliomycetes and Myxomycetes. The Myxomycetes class is more widely represented and has 4 orders. The largest number of species is characteristic of the genera Trichia (8 species), Physarum (6), Arcyria, Diderma (5 species each) and Badhamia (4 species). The most common species in the research area are Lycogala epidendrum, Fuligo septica, Hemitrichia clavata, Trichia varia, Stemonitis axifera, S. fusca, S. splendens and Stemonitopsis typhina. Representatives of slime molds were found on various 18 substrates. The largest number of slime molds species (54) was recorded on Picea schrenkiana. There are 13 species on Populus tremula and 4 species on Betula tianschanica. The remaining substrates are characterized by 1-2 species. It is necessary to note the species of the genus Diderma that appear in early spring after snowfall: Diderma niveum, found on Artemisia juncea and representatives of Poaceae, and D. radiatum on dry grasses, leaves and branches of shrubs.

Humid and cold periods in the last 5600 years in Arid Central Asia revealed by palynology of Picea schrenkiana from Issyk-Kul

Central Asia, with its high mountains, despite its location between Europe and eastern Asia remains a data poor area. However, mountain glaciers are strongly affected by global change and have a wide-ranging impact. A new pollen record over the last 5600 years shows the extension of a dry Artemisia steppe around Lake Issyk-Kul, with a slightly wetter period from 4.5 to 2.7 ka BP (less Ephedra). Picea schrenkiana forest growing on north-facing slopes of the northern Tien Shan Range, are exposed to Westerlies-related precipitation. The pollen record of Picea is therefore a very good marker of wetter and cold conditions. A comparison to a nearby synchronous pollen record at a higher altitude indicates that the whole forest belt moved down, and that it was not a downwards extension of the lower forest limit only. Four cold and humid phases were evidenced over the last 5.6 ka: 5.5 ka, 4.2 ka and following centuries, 3.2 ka and following centuries (before the end of the Bronze Age) and finally the Little Ice Age, with the latter two being more strongly expressed. These climatic changes, in agreement with other Arid Central Asia investigations, corroborate the driving role of the Westerlies far inland. Human activities were more intense in the Mid and Late Bronze Age (4.5–3.2 ka) and in the last 800 years, confirmed by archaeological and historical information. Issyk-Kul and surrounding rich pastureland were most likely an important step in the ancient Silk Road.