No abstract

Russian boreal forests hold a considerable carbon (C) stock and are subjected to frequent surface fires that unbalance C storage and ecosystem function. Although postfire ecological changes aboveground are well understood, biological C flows (e.g., decomposition in the postfire period) remain unclear. We present the results of a long-term field litterbag experiment on needle litter decomposition in typical Larix gmelinii boreal forests in the Russian Far East. For 3 years, we measured mass loss, C and nitrogen (N) concentrations, lignin and manganese dynamics, respiration intensity and enzyme activity in decaying needles, and environmental conditions (temperature and litter moisture). The decomposition rate at 850 days was 0.435 and 0.213 yr−1 in a control forest and in a forest 15 years after a surface fire, respectively. Early stages of needle decay did not differ among sites, whereas decomposition slowed in later stages in burned forest relative to the control (p < 0.01). This was supported by hampered respiration, slow lignin accumulation in decaying needles, and low peroxidase activity in burned forest. We found no direct N release, and decaying litter immobilization was more pronounced in the control forest. In the later stages, we revealed restrained mass loss and associated C release from larch litter in burned forest. Slow and delayed N release may alter organic matter accumulation, the N cycle, and regeneration of the fire-disturbed larch ecosystem. Our investigations highlight hampered C flow from aboveground litter to soil humus even decades after surface fire in a larch ecosystem. Given the climate-induced increase of fire activity, C retained in the litter layer represents a pool that is more vulnerable to the next fire event.

No abstract

Larch forests in the permafrost zone of Eastern Eurasia are exposed to frequent wildfires, which are expected to increase with climate warming. However, little is known about how fire-derived charcoal is linked to the decomposition process in these forests. Fire-derived charcoal can affect the faunal communities in the forest litter. In a two-year field litterbag experiment, we investigated the effect of fire-derived charcoal on the colonisation by microarthropods (Collembola and Acari) of three decomposing litter species dominant in boreal larch forests. Charcoal addition led to an average 15% decrease in body size of collembola but significantly increased their abundance by 5 times throughout the experiment and acari by 1.5 times in the second year of decomposition, and this effect was consistent across all litter species. The increased microarthropod community may have hampered microbial activity and mass loss rate in the presence of charcoal. Charcoal altered the microarthropod community composition, increasing the proportion of collembola up to 20% compared to acari. The difference in abiotic conditions (increased litter water content during dry periods) induced by fire-derived charcoal was a more substantial factor determining the microarthropod community than litter species in the boreal larch forest. Our results indicate that fire-derived charcoal influences the biological drivers of decomposition in boreal larch forests, stimulating the growth of microarthropod community in decomposing litter.

Тенденции развития науки и образования-37-5) огромные возможности для ведения беседы, консультирования с пользователями без посредников. Таким образом, маркетинг в интернетеэто непрерывный процесс с миссиейукрепления позиции бренда предприятия онлайн, привлекая и удерживая потенциальных покупателей, повышая продажи продукции. Огромное количество людей по всему миру постепенно прекращают использовать остальные источники информации, которые на протяжении многих лет не смотрят телевизор, не следят за бумажной прессой, а активно используют интернет. Он мобильнее, проще, рационален. *** Кохан А.Н., Кондратова А.В. Сравнительный анализ методик оценки инвестиционной привлекательности регионов Калининградский государственный технический университет (Россия, Калининград