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Climate change, characterized by warming and precipitation variability, restricted the growth of plants in arid and semiarid areas, and various functional traits are impacted differently. Comparing responses of functional traits to warming and precipitation variability and determining critical water threshold of dominate steppe grasses from Inner Mongolia facilitates the identification and monitoring of water stress effects. A combination of warming (ambient temperature, +1.5°C and +2.0°C) and varying precipitation (−30%, −15%, ambient, +15%, and +30%) manipulation experiments were performed on four Stipa species (S. baicalensis, S. bungeana, S. grandis, and S. breviflora) from Inner Mongolia steppe. The results showed that the functional traits of the four grasses differed in their responses to precipitation, but they shared common sensitive traits (root/shoot ratio, R/S, and specific leaf area; SLA) under ambient temperature condition. Warming increased the response of the four grasses to changing precipitation, and these differences in functional traits resulted in changes to their total biomass, with leaf area, SLA, and R/S making the largest contributions. Critical water thresholds of the four grasses were identified, and warming led to their higher optimum precipitation requirements. The four steppe grasses were able to adapt better to mild drought (summer precipitation decreased by 12%–28%) when warming 1.5°C rather than 2.0°C. These results indicated that if the Paris Agreement to limit global warming to 1.5°C will be accomplished, this will increase the probability for sustained viability of the Stipa steppes in the next 50–100 years.

Evaluating climatic suitability of crop cultivation lays a foundation for agriculture coping with climate change scientifically. Herein, we analyse changes in the climatically suitable distribution of summer maize cultivation in China at 1.5 °C (GW1.5) and 2.0 °C (GW2.0) global warming in the future according to the temperature control targets set by the Paris Agreement. Compared with the reference period (1971–2000), the summer maize cultivation climatically suitable region (CSR) in China mainly shifts eastwards, and its acreage significantly decreases at both GW1.5 and GW2.0. Despite no dramatic changes in the CSR spatial pattern, there are considerable decreases in the acreages of optimum and suitable regions (the core of the main producing region), indicating that half-a-degree more global warming is unfavourable for summer maize production in China’s main producing region. When the global warming threshold increases from GW1.5 to GW2.0, the centres-of-gravity of optimum areas shift northeastward under RCP4.5 and RCP8.5, the centres-of-gravity of both suitable and less suitable areas shift northwestward, though the northward trend is more prominent for the less suitable areas, and the centre-of-gravity of unsuitable areas shifts southeastward. Generally, half-a-degree more global warming drives the cultivable areas of summer maize to shift northward in China, while the west region shows a certain potential for expansion of summer maize cultivation.

Abnormally altered precipitation patterns induced by climate change have profound global effects on crop production. However, the plant functional responses to various precipitation regimes remain unclear. Here, greenhouse and field experiments were conducted to determine how maize plant functional traits respond to drought, flooding and rewatering. Drought and flooding hampered photosynthetic capacity, particularly when severe and/or prolonged. Most photosynthetic traits recovered after rewatering, with few compensatory responses. Rewatering often elicited high photosynthetic resilience in plants exposed to severe drought at the end of plant development, with the response strongly depending on the drought severity/duration. The associations of chlorophyll concentrations with photosynthetically functional activities were stronger during post-tasseling than pre-tasseling, implying an involvement of leaf age/senescence in responses to episodic drought and subsequent rewatering. Coordinated changes in chlorophyll content, gas exchange, fluorescence parameters (PSII quantum efficiency and photochemical/non-photochemical radiative energy dissipation) possibly contributed to the enhanced drought resistance and resilience and suggested a possible regulative trade-off. These findings provide fundamental insights into how plants regulate their functional traits to deal with sporadic alterations in precipitation. Breeding and management of plants with high resistance and resilience traits could help crop production under future climate change.

Responses of plant biomass and yield components to warming are species-specific and are shifted as increased warming magnitude rises; this finding improves the results of IPCC AR5. The responses of crop yields to climatic warming have been extensively reported from experimental results, historical yield collections, and modeling research. However, an integrative report on the responses of plant biomass and yield components of three major crops to experimental warming is lacking. Here, a meta-analysis based on the most recent warming experiments was conducted to quantify the climatic warming responses of the biomass, grain yield (GY), and yield components of three staple crops. The results showed that the wheat total aboveground biomass (TAGB) increased by 6.0% with general warming, while the wheat GY did not significantly respond to warming; however, the responses shifted with increases in the mean growing season temperature (MGST). Negative effects on wheat TAGB and GY appeared when the MGSTs were above 15 °C and 13 °C, respectively. The wheat GY and the number of grains per panicle decreased by 8.4% and 7.5%, respectively, per degree Celsius increase. Increases in temperature significantly reduced the rice TAGB and GY by 4.3% and 16.6%, respectively, but rice straw biomass increased with increasing temperature. However, the rice grain weight and the number of panicles decreased with continuous increasing temperature (ΔTa). The maize biomass, GY, and yield components all generally decreased with climatic warming. Finally, the crop responses to climatic warming were significantly influenced by warming time, warming treatment facility, and methods. Our findings can improve the assessment of crop responses to climatic warming and are useful for ensuring food security while combating future global climate change.

The main characteristics of global climate change include significant temperature increases and uneven precipitation distributions, which are both limiting factors for the sustainable development of dryland agriculture in semiarid regions. Inner Mongolia, which occupies the largest area of the semiarid region in China, is a good representation of the region’s climate and dryland agricultural conditions. Spring wheat is widely grown in this region, but the negative impacts of climate change have seriously threatened spring wheat production in recent years. To adapt to these changes, it is imperative to study the influence of climate change on spring wheat production. We employed a vulnerability assessment method to quantitatively evaluate the impacts of climate change on spring wheat production in Inner Mongolia and recommended specific countermeasures based on the results. The average temperature and precipitation during the spring wheat growing season was 16.5 °C and 224 mm, respectively, from 1961 to 2012. Northeastern Inner Mongolia was characterized by lower temperature and higher precipitation; the eastern region had both higher temperature and precipitation; and the southwestern area had higher temperature and lower precipitation. The climate in this region showed a warming and drying trend from 1961 to 2012, with average temperature during the spring wheat growing season increasing with an average rate 0.3 °C/10a and average precipitation decreasing with an average rate 4.3 mm/10a. Over the study period (from 1996 to 2012), the vulnerability of spring wheat in the eastern, central, and southwestern areas of Inner Mongolia was high, whereas that in the northeast was relatively low. Assuming the adaptive capacity of spring wheat is stable, the comprehensive unit vulnerability of spring wheat production is expected to significantly increase under the investigated climate change scenarios (based on historical climate trends and RCP4.5, RCP8.5 scenarios) relative to average values over the study period. Exposure and regional vulnerability could be reduced by decreasing the proportion of spring wheat grown in vulnerable areas, such as the central and southwestern areas of Inner Mongolia.

As the global climate changes, different degrees of variation in climatic factors will have various impacts on agricultural production, leading to appropriate or stressed conditions. The impact threshold of climate change (ITCC) for agriculture refers to the value of a climatic factor at which the agricultural status mutates. Due to the urgency of addressing the negative impacts of climate change on agriculture, research on the ITCC of agriculture is crucial. Here, we built models to reflect the relationship between agricultural climate yield and climatic factors based on climate change characteristics and objective agricultural status. Using the models, we obtained the appropriate and stressed thresholds of different climatic factors. We calculated the ITCC of spring wheat in Wuchuan County as an example and identified warming and drying trends in Wuchuan County from 1961 to 2013, especially during the period from 1991 to 2013 (i.e., the period after mutation or the change period). Over the past 53 years, spring wheat yield increased with an average rate of 81.3 kg ha−1 dec−1. Over the change period, however, yield decreased with an average rate of 13.8 kg ha−1 dec−1 and the fluctuation range increased. The appropriate threshold for average temperature during the growth period of spring wheat was 11.4 °C, and the stressed thresholds were 8.2 and 14.6 °C. The appropriate threshold for precipitation during the growth period was 391.1 mm, and the stressed thresholds were 247.4 and 534.9 mm. During the period before mutation (i.e., the basic period), the average temperature was below the upper temperature threshold, and precipitation was 26.9 mm above the lower precipitation threshold. During the change period, the average temperature was 0.3 °C above the upper temperature threshold, and precipitation was 9.8 mm above the lower precipitation threshold.

Global warming and dimming/brightening have significant implications for crop systems and exhibit regional variations. It is important to clarify the changes in regional thermal and solar radiation resources and estimate the impacts on potential crop production spatially and temporally. Based on daily observation data during 1961&ndash, 2015 in the North China Plain (NCP), the impacts of climate change associated with climate warming and global dimming/brightening on potential light&ndash, temperature productivity (PTP) of summer maize were assessed in this study. Results show that the NCP experienced a continuous warming and dimming trend in maize growing season during the past 55 years, and both ATT10 and solar radiation had an abrupt change in the mid-1990s. The period of 2000&ndash, 2015 was warmer and dimmer than any other previous decade. Assuming the maize growing season remains unchanged, climate warming would increase PTP of summer maize by 4.6% over the period of 1961&ndash, 2015, which mainly occurred in the start grain filling&ndash, maturity stage. On the other hand, as negative contribution value of solar radiation to the PTP was found in each stage, dimming would offset the increase of PTP due to warming climate, and lead to a 15.6% reduction in PTP in the past 55 years. This study reveals that the changes in thermal and solar radiation have reduced the PTP of summer maize in the NCP. However, the actual maize yield could benefit more from climate warming because solar radiation is not a limiting factor for the current low production level.

Spring maize (Zea mays L.) is a thermophilic C4 crop which is sensitive to climate change. This paper provides a detailed assessment of the effect of climate change on the crop from a new perspective, by predicting the probability of the potential distribution of spring maize across China. The affected area of spring maize suitability was identified, and then the affected area was subdivided into the improved area and the deteriorated area. Our results confirmed that there was a detrimental consequence for spring maize suitability under observed climate change from 1961&ndash, 1990 to 1981&ndash, 2010. However, our results revealed that warming scenarios of 1.5 &deg, C and 2 &deg, C were helpful for the suitable area expansion of spring maize. The affected area was smaller under warming scenarios than under historical climate change, revealing that temperature rise alone was not enough to trigger a &ldquo, tipping point&rdquo, (a threshold value after which abrupt shifts occur) for spring maize, even if warming is 2 &deg, C above the level of 1961&ndash, 1990. Our results not only benefit China in the design of mitigation and adaptation strategies, but also provide a theoretical judgement that the impact of global warming on the crop ecosystem is not serious if other climate factors remain unchanged.

It is important research fields of global change ecology to study the influence that global climate change has on ecosystem and agroforestry, environmental factor such as water resources. And it is also important scientific basis on which to cope with climate change, to manage ecosystem adaptively and to make relevant policies. If the change of the earth system’s strength power is the ultimate concern of global climate change study, it will be to focus on questions to recognize the change of ecosystem’s structure, process, and function motivated by climate change and human activities. The earth feeds on massive diverse natural ecosystem, and diverse semi-natural semi-artificial ecosystem, which is already a result of a long-term adaption of the earth to natural environment and human activities. In that case, the adaption research of the ecosystem to the environment change plays a key role in humans getting to know what influence global changes may have on the supporting capacity of earth system. This chapter mainly concerns about the ecosystem’s adaptability. It is defined as the adaptive abilities of lowering environment changes’ negative influence and making good use of favorable opportunities when environment changes but the ecosystem tries to maintain its main functions. And this balance mechanism and adaptability of ecosystem is a basis on which to judge the influence degrees of global changes on ecosystem’s structure and function. To dig into this question, we generally study from two different perspectives, one of which is global changes’ influence on the ecosystem, and the other one is the ecosystem’s responses to these changes, which is the principal framework of this chapter.