Abstract:Taking Sanjiang Plain, a typical black soil region, as the study area, and the least squares method was used to reveal the change trend of terrestrial ecosystem carbon stocks under climate change in 1990—2020. By means of barycentric analysis and cold hot spot analysis, the spatial and temporal differentiation of terrestrial ecosystem carbon stocks in study area was revealed, and the influence of climate factors on carbon stocks was analyzed by geographical weighted regression method. CMIP6 data were used to simulate and predict terrestrial ecosystem carbon stocks under SSP585 and SSP245. The results showed as follows: under the background of climate change, carbon storage in study area showed a fluctuating trend of decline in 1990—2020, and carbon storage loss was about 2.66×107t. The regions with high carbon storage value were mainly distributed in the northwest and east, while the regions with low carbon storage value were mainly distributed in the north and southeast. The rate of carbon storage decline in the study area was changed greatly in 1990—2020, and the rate of carbon storage decline in Hegang City was the largest, while the rate of carbon storage decline in Jiamusi City was the minimum. The center of gravity of carbon storage in study area was shifted 1340m to the northeast in 1990—2020, and 1680m to the northeast in 2000—2020. The distribution pattern of carbon storage hotspots was sheet-like and blocky, and the distribution pattern of cold spots was sheet-like and banded, the range of hot spots was basically unchanged, and the range of cold spots was reduced. The relationship between annual temperature, annual precipitation and carbon storage in study area was significant in 1990—2020, showing a positive and negative interleaving spatial pattern. Climate and land use change determined the spatio-temporal pattern of carbon storage, and forest-forest land and cultivated land-cultivated land led to the greatest loss of carbon storage. Under the SSP585 and SSP245 scenarios, the carbon reserves in study area in 2030 were 2.22×107t and 2.26×107t, respectively, which were reduced by 2.17×107t and 2.13×107t compared with that in 2020, respectively. The spatial distribution pattern of carbon reserves was not changed significantly, but the areas of cold hot spots were reduced. The center of gravity would continue to shift 6525m and 6000m to the northeast.