The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid-Cret...The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid-Cretaceous is characterized by major geological events that affected the global environment. δ^18O, palaeothermometer TEX86, and other climatic indices from marine sediments suggest rapid temperature increase during mid-Cretaceous despite occasional short cooling events. Simultaneously, terrestrial deposits in East Asia changed from coal-bearing to shale, then to red beds and evaporites. Plant assemblages and other paleoclimate indicators point to rapid aridification for midCretaceous terrestrial environments. In addition, the wildfires were frequently spread all over the earth by the numerous charcoal evidence during the Mid-Cretaceous. Thus, we speculate that the seasonally dry and hot conditions of mid-Cretaceous created a fiery hothouse world. Early angiosperms increased in abundance and diversity and evolved from a few aquatic species to terrestrial herbaceous and then to the diversified flora of today. Angiosperms showed rapid physiological evolution in vein density and leaf area that improved photosynthesis and water absorption. These ecophysiological changes made early angiosperms well adapted to the hot and dry environment in mid-Cretaceous. Moreover, these physiological changes facilitated the fire–angiosperm cycles in mid-Cretaceous that likely further stimulated the early angiosperm evolution.展开更多
The paper presents a study on increasing energy independence of a 200 m2 horticultural hothouse, by means of heating it with thermal energy from a TLUD （top-lit-up-draft） gasification procedure of local residual agr...The paper presents a study on increasing energy independence of a 200 m2 horticultural hothouse, by means of heating it with thermal energy from a TLUD （top-lit-up-draft） gasification procedure of local residual agricultural biomass, chopped at 10-50 mm and dried at 10%-15% RH （relative humidity）. It produces an average of 14% higt quality biochar. Hot-air heating system and forced circulation are equipped with two GAZMER 40/150G energetic modules, which are rechargeable, simple, safe, efficient and environmentally friendly. They can gasify chopped or pelletised biomass. To study the microclimate evolution, it was used a complex numerical model for a 200 m2 hothouse for growing vegetables. Simulated experiments were carried out for frosty days and, estimated, for the whole warming period. Each year 13.44 t of biomass are consumed, resulting 1.78 t ofbiochar which, when introduced in soil, produces a -6.2 t/year negative balance of CO2.展开更多
基金supported by the National Natural Science Foundation of China(No.41602023,41402007)the Key Laboratory Project of Gansu Province(Grant No.1309RTSA041)
文摘The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid-Cretaceous is characterized by major geological events that affected the global environment. δ^18O, palaeothermometer TEX86, and other climatic indices from marine sediments suggest rapid temperature increase during mid-Cretaceous despite occasional short cooling events. Simultaneously, terrestrial deposits in East Asia changed from coal-bearing to shale, then to red beds and evaporites. Plant assemblages and other paleoclimate indicators point to rapid aridification for midCretaceous terrestrial environments. In addition, the wildfires were frequently spread all over the earth by the numerous charcoal evidence during the Mid-Cretaceous. Thus, we speculate that the seasonally dry and hot conditions of mid-Cretaceous created a fiery hothouse world. Early angiosperms increased in abundance and diversity and evolved from a few aquatic species to terrestrial herbaceous and then to the diversified flora of today. Angiosperms showed rapid physiological evolution in vein density and leaf area that improved photosynthesis and water absorption. These ecophysiological changes made early angiosperms well adapted to the hot and dry environment in mid-Cretaceous. Moreover, these physiological changes facilitated the fire–angiosperm cycles in mid-Cretaceous that likely further stimulated the early angiosperm evolution.
文摘The paper presents a study on increasing energy independence of a 200 m2 horticultural hothouse, by means of heating it with thermal energy from a TLUD （top-lit-up-draft） gasification procedure of local residual agricultural biomass, chopped at 10-50 mm and dried at 10%-15% RH （relative humidity）. It produces an average of 14% higt quality biochar. Hot-air heating system and forced circulation are equipped with two GAZMER 40/150G energetic modules, which are rechargeable, simple, safe, efficient and environmentally friendly. They can gasify chopped or pelletised biomass. To study the microclimate evolution, it was used a complex numerical model for a 200 m2 hothouse for growing vegetables. Simulated experiments were carried out for frosty days and, estimated, for the whole warming period. Each year 13.44 t of biomass are consumed, resulting 1.78 t ofbiochar which, when introduced in soil, produces a -6.2 t/year negative balance of CO2.
