Effects of Forest Fire on Biosphere and Cryosphere -Biodiversity and Carbon Droxide Cycle of in Northern Eurasia-

The results of The present project are summarized as follows:1. BiomassLarch forests in permafrost area near Yakutsk show pure and uniform forest types. Tree height andstand density of a 22-year-old, a 120-year-oldand a more than 200-year-old forests are about 5 m and 10,000 trees/ha, 10 m and 6,000 trees/haand 9 - 13 m and 2000 trees/ha respectively. The biomass above ground increased straight from 16.2t/ha to 149.6 t/ha with increasing the age until around 120 years old. the maximum biomass estimatedfrom 31 stands reported previously around Yakutsk was about 150 t/ha. The biomass and The leaf masspositively correlated with diameter at 1.3 m.2. Biodiversity：106 plant species which included 16 tree species and 90 herbaceous plants记录在our研究sites during the investigation periods. VaccinumArctous and lichens dominant on the forest floor of old growths. Specific plant speciescorresponded to high pH or soil moisture appeared at alas meadow. Collembola and Cryptostigmata Collembola and Cryptostigmatadecreased their density to the lowest value at 6 years after forest fire and increased them withbeing recovered by larch forest. The density of both Collembola and Cryptostigmata positivelycorrelated with the nitrogen content of soil and that of Cryptostigmata negatively correlated with the nitrogen content of soil and that of Cryptostigmata negatively correlatedhigh soil pH.3. Carbon cycle and methon flux：Net ecosystem production(NEP) of larch old growth was estimated at 129gc /m D12 yr from soilrespiration and net主要生产however that of the forest fired strongly was -88 gC/m D12 /yr，namely a source of CO - D22 - D2. Forest soil fired or not was absorbing NH - D24 - D2 but the edge ofmarsh in alas was emitting NH - D24 - D2。

The results of the present project are summarized as follows:1. Biomass: Larch forests in permafrost area near Yakutsk show pure and uniform forest types. Tree height and stand density of a 22-year-old, a 120-year-old, and a more than 200-year-old forests are about 5 m and 10,000 trees/ha, 10 m and 6,000 trees/ha, and 9〜13 m and 2,000 trees/ha respectively. The biomass above ground increased straight from 16.2 t/ha to 149.6 t/ha with increasing the age until around 120 years old. The maximum biomass estimated from 31 stands reported previously around Yakutsk was about 150 t/ha. The biomass and the leaf mass positively correlated with diameter at 1.3 m.2. Biodiversity : 106 plant species which included 16 tree species and 90 herbaceous plants were recorded in our research sites during the investigation periods. Vaccinum, Arctous and lichens were dominant on the forest floor of old growths. Specific plant species corresponded to high pH or soil moisture appeared at alas meadow. Collembola and Cryptostigmata decreased their density to the lowest value at 6 years after forest fire and increased them with being recovered by larch forest. The density of both Collembola and Cryptostigmata positively correlated with the nitrogen content of soil and that of Cryptostigmata negatively correlated with the high soil pH.3. Carbon cycle and methon flux: Net ecosystem production(NEP) of larch old growth was estimated at 129 gC/mィイD12ィエD1/yr from soil respiration and net primary production, however that of the forest fired strongly was -88 gC/mィイD12ィエD1/yr, namely a source of COィイD22ィエD2. Forest soil fired or not was absorbing NHィイD24ィエD2 but the edge of marsh in alas was emitting NHィイD24ィエD2.