Search

Agriculture need to adapt to the climate impacts. Such processes should be both socially equitable and environmentally sustainable if the aim is more inclusive development. This paper reviews the literature on agricultural adaptation to climate variability and change to show how governments, institutions and farmers are adopting measures to cope with changes in temperature and rainfall patterns as well as weather extremes, and the extent to which and how social equity issues, ecological sustainability issues and the empowerment of farmers are taken on board in different parts of the world. The framework of inclusive eco-efficient and climate-smart agriculture is proposed to confront climate change and ensure food security by enhancing resilience, increasing sustainable productivity, reducing inequality and promoting shared prosperity.

Drought is a recurrent meteorological phenomenon that can be disastrous for humans; however, drought characteristics vary substantially in different regions. We use meteorological data from 140 stations in Northeast China for the period 1970–2014 to calculate the reconnaissance drought index (RDI) in order to examine droughts. We also analyze the strength of the relationships between the main large-scale atmospheric circulation patterns and RDI. Drought trends in the region are largely decreasing, but in the majority of cases, there is no statistical significance. Spatially, the pattern of droughts is a less frequent occurrence with greater severity and longer duration, mainly in the western part of the region. Severe droughts for the periods 1975–1979 and 2000–2004 were found, and most of these droughts occurred in the western part of Northeast China. The correlations between RDI and the atmospheric circulation indices POL, IAZC, and IEAT are negative, but the correlation between RDI and PDO is positive. The relationship between RDI and POL is stronger than the others, and the lagged effect is particularly obvious; thus POL can be recognized as the major driver of droughts over the period 1970–2014 in Northeast China.

Potato grows in most part of China, it achieves higher yield and better quality in Gansu Province than in others. With global warming, its growth duration has been prolonged and sowing date become earlier than before. Therefore, to regulate its sowing date and growing period is of great significance for better harvest. In this study, experiments were conducted with six sowing-date treatments of potato in Dingxi, which is in the Loess Plateau of central Gansu Province in Northwest China in 2010. The growth period, morphological index and change in yield and their relationships with temperature, precipitation, and other climatic factors were investigated for each treatment. Results show that the crop with different sowing dates experienced different climate conditions, leading to distinct growth duration, plant height, and leaf area index. The growth duration was shortened due to a delay in sowing date. For each 15-day delay in sowing, the growth duration was reduced by 12 days on average. A significant linear relationship was found between numbers of days either from seeding to emergence or from flowering to harvest and mean temperature over the corresponding period. Dry matter accumulation, tuber fresh weight, and final yield were all decreased because of insufficient cumulative temperature over the shorter growing periods. Marked differences in tuber yield were discovered among the six treatments of sowing date, the potato planted on May 27 giving the highest yield. The potato planted either earlier or later would produce invariably lower yield than the treatment of May 27. Late May therefore can be taken as the optimum sowing time of potato in this region because the crop can fully utilize thermal resource. We conclude that to postpone sowing time is a good practice for potato production to adapt to climate warming in the Loess Plateau of central Gansu, China.

Urban greening helps cooling and humidifying the air; shading provided by buildings also affects outdoor thermal environment. Therefore, they both influence the thermal perceptions of people in outdoor spaces. The sky view factor (SVF) is a commonly used parameter in the research on urban climate, indicates the relationship between the visible area of the sky and the area covered by urban structures. The current paper first gives a brief introduction of the SVF and fisheye imagery. It then describes a method conducted to estimate SVF for urban environment analysis by using fisheye lenses and applying the ENVI platform as well. Finally, micro-climate characteristics over three typical urban underlying surfaces, including sunlit asphalt roads, shaded roads by building and by chinars were analyzed based on on-site observations. For a high-density city such as Nanjing, the present study reveals that the higher building shaded, chinar canopy density, and the lower sky transmittance, humidification and cooling of the air is more significant under the same climate condition and the same road. For benefiting urban environmental planning and assessment in high-density cities, more cases simulation with different combinations of factors are needed, which can provide a set of better greening guides and the optimal shading level.

Field experiments including one soybean growing season and one winter-wheat growing season were adopted. The experimental field was divided into four equal-area sub-blocks which differed from each other only in tillage managements, which were conventional tillage (T) , no-tillage with no straw cover ( NT) , conventional tillage with straw cover (TS) , and no-tillage with straw cover (NTS). CO₂ and N₂O emission fluxes from soil-crop system were measured by static chamber-gas chromatograph technique. The results showed that: compared with T, in the soybean growing season, NTS significantly increased the cumulative amount of CO₂ (CAC) from soil-soybean system by 27.9% (P = 0.045) during the flowering-podding stage, while NT significantly declined CAC by 28.9% (P = 0.043) during the grain filling-maturity stage. Compared with T, NT significantly declined the cumulative amount of N₂O (CAN) by 28.3% (P = 0.042) during the grain filling-maturity stage. In the winter-wheat growing season, compared with T, TS and NT significantly declined CAC by 24.3% (P = 0.032) and 36.0% (P = 0.041) during the elongation-booting stage, and also declined CAC by 26.8% (P = 0.027) and 33.1% (P = 0.038) during the maturity stage. During the turning-green stage, compared with T treatment, NT, NTS, and TS treatments had no significant effect on CAN, while NTS significant declined CAN by 42.0% (P = 0.035) compared with NT. Our findings suggested that conservation tillage managements had a more significant impact on CO₂ emission than 20 emission from soil-crop system.

The effects of simulated heat waves on body weight, body temperature, and biomarkers of cardiac function in ApoE-/- mice were investigated. Heat waves were simulated in a meteorological environment simulation chamber according to data from a heat wave that occurred in July 2001 in Nanjing, China. Eighteen ApoE-/- mice were divided into control group, heat wave group, and heat wave BH4 group. Mice in the heat wave and BH4 groups were exposed to simulated heat waves in the simulation chamber. Mice in BH4 group were treated with gastric lavage with BH4 2 h prior to heat wave exposure. Results showed that the heat waves did not significantly affect body weight or ET-1 levels. However, mice in the heat wave group had significantly higher rectal temperature and NO level and lower SOD activity compared with mice in the control group (p &lt, 0.01), indicating that heat wave had negative effects on cardiac function in ApoE-/- mice. Gastric lavage with BH4 prior to heat wave exposure significantly reduced heat wave-induced increases in rectal temperature and decreases in SOD activity. Additionally, pretreatment with BH4 further increased NO level in plasma. Collectively, these beneficial effects demonstrate that BH4 may potentially mitigate the risk of coronary heart disease in mice under heat wave exposure. These results may be useful when studying the effects of heat waves on humans.

Field experiments were conducted in the 2008-2009 soybean and winter wheat-growing sea- sons to assess soil respiration (SR) and nitrous oxide (N2O) emission as affected by enhanced UV-B radia- tion and straw incorporation. The SR rate was mea- sured using a soil CO2 flux system; the N2O flux was measured using a static chamber-gas chromatograph technique. The results showed that in the soybean and winter wheat-growing seasons, enhanced UV-B radia- tion significantly decreased the SR rates and that straw incorporation increased the SR rates compared to the control treatment. The combined treatment of UV-B and straw incorporation had no obvious influence on the SR rates. Enhanced UV-B radiation, straw incor- poration, and the combination treatment increased the temperature sensitivity of SR in the soybean-growing season. The study also showed that N2O emissions were reduced by enhanced UV-B radiation and that straw incorporation had no significant effects on the mean N2O emission fluxes in the soybean and winter wheat-growing seasons. Our findings suggest that enhanced UV-B radiation may lead to a decrease in SR and in N2O emissions, straw incorporation may increase SR, and the combined treatment may have no significant influence on SR and N2O emissions from soybean-winter wheat rotation systems.

To investigate the effects of elevated nitrogen deposition on forest soil respiration, a simulated nitrogen deposition field experiment was conducted in northern subtropical deciduous broad-leave forest from April 2008 to April 2009. Nitrogen treatments included the control (no N addition, CK), low-N [50 kg x (hm2 x a)(-1), T(L)], medium-N [100 kg x (hm2 x a)(-1), T(M)], and high-N [150 kg x (hm2 x a)(-1), T(H)]. The respiration rates were measured by a static chamber-gas chromatograph method. Results showed that nitrogen deposition did not change the seasonal and daily variation patterns of soil respiration. Compared to the control, T(L), T(M) and T(H) treatments reduced soil annual average respiration rates by 8.51%, 9.74% and 11.24%, respectively. Meanwhile, T(L), T(M) and T(H) treatments decreased daily average soil respiration rates by 4.42%, 11.09% and 12.17%, respectively. Significant relationship was found between soil respiration rate and soil temperature. The Q10 (temperature sensitivity coefficients) for soil respiration of CK, T(L), T(M), and T(H) treatments were 2.53, 3.22, 2.64 and 2.92, respectively. Our findings suggested that nitrogen deposition reduced soil respiration, and increased soil respiration temperature sensitivity in northern subtropical deciduous broad-leave forest.

Field experiment was carried out in 2008 in order to investigate the effects of enhanced UV-B radiation and straw application on soil respiration in soybean field. LI-8100 automated soil CO2 flux system was used to measure soil respiration under 20% enhanced UV-B radiation, straw application, 20% enhanced UV-B radiation + straw application and control. Environmental factors such as air temperature, soil temperature and moisture were also measured. Results indicated that supplemental UV-B radiation reduced soil respiration rate by 30.31%, straw application increased soil respiration rate by 14.51%, while enhanced UV-B radiation + straw application combined treatment had no significant effect on soil respiration. Enhanced UV-B radiation enhanced the carbon conversion rate of straw. Significant relationship were found between soil respiration rate and soil temperature under the control, enhanced UV-B, straw application, and enhanced UV-B + straw application, the fitting equation determined coefficients R2 were 0.434, 0.563, 0.451 and 0.513. The Q10 (temperature sensitivity coefficients) for soil respiration were 1.55, 1.91, 1.80 and 1.71, respectively. It was reflected that enhanced UV-B radiation, straw application and enhanced UV-B radiation + straw returning increased the Q10 for soil respiration.

Based on the data of solar radiation and air pollutants collected in Beijing, the relationship between surface ultraviolet (UV) radiation and the content of air pollutants were analyzed, using the radiative transfer model TUV4.4 (Tropospheric Ultraviolet Visible). The results show that average total ozone content is 329 DU and higher in winter and spring, lower in summer and autumn. The inverse relationship exists between ground level UV radiation and total ozone content. This study also shows that a substantial reduction (up to 50%) in the UV radiation on days with high levels of air pollution. Larger fluctuations are found in UV radiation in the summer. The effects of clouds and air pollution on UV are higher than on total solar radiation, and the reduction in UV is about twice as large as the total solar radiation values. Strong reduction in the UV radiation reaching the ground is associated with the increase of tropospheric ozone and nitrogen oxides in Beijing. The correlation coefficient between ozone concentration and decrease in UV radiation is 0.70 in the early afternoon.

Ozone (O3) is a primary gaseous contaminant in urban ambient, and its variation correlates well with nitrogen oxides (NO(x) = NO+ NO2). Continuous monitoring in the urban area from August 2004 to July 2005 was carried out in Beijing, using 49C ozone analyzer and 42CTL NO-NO2-NO(x) gas analyzer. The results show that peak O3 and oxidant (OX = O3 + NO2) concentrations in Beijing often appear at about 15:00 in the early afternoon, the diurnal variation of NO, concentrations show a very clear cycle with two peaks, one appears at about 07:00 in the morning and the other is at 23:00 in the evening. However, concentrations variation in four seasons are not same. The highest concentrations of O3 and NO(x) appear in summer and winter, respectively. The NO, crossover point occurs at about 100 x 10(-9) volume ratio. At lower level, NO2 is the major component of NO(x), whereas NO dominates at higher mixing ratio. It is also shown that the level of OX is made up of two contributions, regional contribution and local contribution. The former is affected by regional background O3 level, with the maximum in spring, whereas the latter is effectively correlates with the level of primary pollution, with the maximum in summer. Diurnal variation also appears in the concentrations of the components of oxidants.