Microclimate Characteristics of the Primitive Abies Delavayi var.Motuoensis in Medog,Xizang
Under the influence of the warm and humid airflow of the Indian monsoon,a large number of primitive moist forests dominated by Abies delavayi var.motuoensis are distributed at higher altitudes in Medog,southeast Xizang Autonomous Region,and the study of forest microclimate in this area can provide a theoretical basis for vegetation protection in alpine ecological fragile zones.In this study,based on the microclimate monitoring data inside and outside the fir forest at Xirong Gully(2 700 ma.s.l)in Medog in 2020,we compared the seasonal char-acteristics of air temperature,humidity and soil temperature at different depths inside and outside the forest,and further explored the growing season length and the occurrence of low-temperature events during the growing sea-son based on the air and soil temperature.The results showed that:(1)at the daily scale,the air temperature in-side the forest was 0.2～2.7℃lower than that outside the forest at daytime,and the forest showed a cooling effect.The air temperature inside the forest was 0.2～1.2℃higher than that outside the forest at nighttime except in sum-mer,which indicated that the forest reflected an insulating effect.In terms of seasonal changes,the highest air temperature appeared in August both inside and outside the forest,and the lowest occurred in January,and the air temperature inside the forest was more stable than outside.(2)The relative humidity at different seasons showed a higher value inside the forest than outside.(3)The daily changes in soil temperatures showed similar dynamics with air temperature except for winter,and lagged behind by about 2～3h.The soil temperature at differ-ent depths in spring and summer showed a sequence of 5 cm>10 cm>20 cm,while it reversed in autumn and win-ter.(4)The growing season length based on air temperature was 208 days,while that based on soil temperature was significantly longer(256～268 days).(5)During 2020,the frequency,intensity and duration of low-tempera-ture events in fir forest were 1 day,-0.03°C and 1 h,respectively,which were 6 days,0.86°C,and 7 h weaker than that of habitats outside of the forest.The above studies indicated that the virgin Abies delavayi var.motuoen-sis forest played an important role in insulating and buffering the effects of low-temperature events.The observa-tion and research on forest microclimate should be strengthened in the future protection and management of natu-ral subalpine forests,which may enhance the potential resilience of natural forests to climate change.
low-temperature eventair temperaturesoil temperatureAbies delavayi var.motuoensisgrowing season length
NETL
NSTL
万方数据
维普
