No abstract

In a scenario of climate change and intensive land-use change, the issue of salt marsh degradation caused by global warming and soil salinization is becoming more serious. A climate chamber experiment was conducted to examine the responses of tuber sprouting and seedling growth of Schoenoplectus nipponicus to variations in the temperature regimes (20/10, 25/15, 30/20 and 35/25°C; 12-h light/dark 12-h photoperiod) and different salt concentrations (0, 50, 75, and 100 mmol/L salinity). Results showed that the final sprouting percentage decreased with the increase in salinity and increased with the rising temperature. Salinity lower than 50 mmol/L was the most favorable for tuber sprouting. Under high salinity (75 and 100 mmol/L salinity), the inhibition of tuber sprouting at 20/10°C was greater than other temperature regimes. Along the temperature gradients, both plant height and leaf N content increased, and root length decreased under non-saline-alkali conditions, while plant height, leaf N content, and root length declined significantly under salt stress (50, 75, and 100 mmol/L salinity). With the increase in temperature, the production of tubers under the control treatments was enhanced significantly, but that under salt stress declined significantly. Under 0 mmol/L salinity, the accumulation of biomass in various organs increased with rising temperature. Biomass accumulation increased first and then declined for plants grown under salt stress, with a peak value of 25/15°C. Root: shoot ratio was reduced significantly under the combination of high salt stress (75 and 100 mmol/L salinity) and high temperatures (30/20°C and 35/25°C). Our study will contribute to a better understanding of the influence of climate warming and increasing serious human disturbances on this important wetland species.

The potential of CO2 injection in stimulating tight oil recovery after primary production has been extensively demonstrated previously. However, the processes of mass transport and exchange inside dual-permeability matrix-facture system driven by CO2 remain unclear. To improve our understanding and supplement the existing knowledge, three types of matrix-fracture models were designed and employed to mimic CO2 injection processes (huff-n-puff and flooding modes), named fully open fracture (FOF), partially open fracture (POF), and crossed open fracture (COF) models, respectively. CO2 huff-n-puff and flooding experiments were conducted on these three models to observe the dynamics of pressure and oil recovery factor. Core-scale models were built up by history-matching the oil recovery dynamics through modifying the relative permeability curves based on Corey correlations. The mass transport and exchange processes with the proceeding of CO2 injection were delineated. The results showed that either CO2 huff-n-puff or CO2 flooding was capable of extracting the oil from tight matrix substantially but the increase in oil recovery factor became insignificant with the increase in cycle number or injection time. The oil resided in the proximity of injector, fracture and producer were primarily recovered during CO2 flooding. In the FOF and COF models, the matrix oil near the injector and producer was mainly mobilized. As for CO2 huff-n-puff, the oil saturation of the three models was reduced uniformly throughout the cores with cycles. The high sweep efficiency of CO2 largely mobilized the oil near the injector. It can be generally concluded that injecting CO2 by huff-n-puff protocol might be more beneficial than flooding mode for unconventionals. The results of this paper can provide insights into the oil recovery dynamics and mass transport and exchange induced by CO2 injection in tight reservoirs.

No abstract

Early recruitment process dominated by vegetation reproduction for wetland plant is a key life-history stage affecting species distribution. Extreme climatic events, such as extreme temperature and heavy rainfall have been predicted to become more intense and frequent under future climate scenarios. To explore the effect of temperature and ooding depth on tubers sprouting and early growth of Bolboschoenus planiculmis, we conducted two arti cial experiments in the incubator and greenhouse,

Current climate models predict more intense rainstorms and temperature extreme events under future global climate change. Estimation of environmental factors thresholds might provide important information for the common patterns of species distributions and management of wetland ecosystems. The laboratory experiment

Early recruitment process dominated by vegetation reproduction for wetland plant is a key life-history stage affecting species distribution. Extreme climatic events, such as extreme temperature and heavy rainfall have been predicted to become more intense and frequent under future climate scenarios. To explore the effect of temperature and flooding depth on tubers sprouting and early growth of Bolboschoenus planiculmis, we conducted two artificial experiments in the incubator and greenhouse, including ten temperature regimes (8, 10, 12, 14, 16, 19, 22, 25, 28 and 31°C), and ten flooding depth treatments (-5, 0, 3, 6, 9, 12, 16, 20, 30 and 40 cm). The results showed that the temperature and flooding depth had significant effect on the tuber sprouting and ramet early growth. The estimated base temperature for the sprouting is 6.2°C, the final sprouting percentage increased parabolically with increasing temperature and reached a maximum of 61.09% at 25.4°C. The final sprouting percentage increased first and then decreased with increasing flooding depth, and reached a maximum of 96.04% at 3.92 cm. The ramet height increased first and then decreased with increasing flooding depth, and reached a maximum of 61.29 cm at 8.20 cm. Our study will provide a basis for understanding and predicting the influence of climate change on the distribution of B. planiculmis.