Climate variations and New Zealand agriculture: the CLIMPACTS system and issues of spatial and temporal scale

Effects of Climate Change on Cultivation Patterns and Climate Suitability of Spring Maize in Inner Mongolia

Climate change has caused significant alterations in crop cultivation patterns and has affected crop suitability as well as its production. In this study, we investigated the changes in cultivation patterns and climate suitability of spring maize in Inner Mongolia from 1959 to 2018. We used the daily meteorological data from 50 weather stations and growth period data of spring maize from nine agrometeorological stations. In addition, the quantitative and interdecadal relationship between climate suitability of regions and climate-induced crop yield was analyzed using stepwise regression and cross wavelet transform. The results show that: (1) The planting boundaries of different spring maize maturity types extend to the north and east. In the middle part, early maturity maize has been replaced by medium maturity maize. The unsuitable planting areas in Northeast Inner Mongolia are decreasing, and the early maturity areas are increasing. (2) The climate suitability for spring maize planting areas is increasing. However, variations occur between different regions; the eastern region has the highest climate suitability (Sz = 0.67), but the overall trend is decreasing in this region. Whereas the central region has moderate suitability (Sz = 0.62), with a significantly increasing trend (p < 0.05). The western region is lower (Sz = 0.60) and the trend is not significant. (3) Climate suitability and climate-induced yields are generally positively correlated. The primary factors affecting climate-induced yields are sunshine hours, followed by climate suitability, rainfall, and temperature. The cross-wavelet transform shows that climate suitability and climate-induced yield have greater periodicity in the late growth period. Appropriate expansion of the planting range of medium-late maturity spring maize can fully adapt to the impact of climate warming. Therefore, it is necessary to study suitability trends of regions to adopt comprehensive maize production measures.

Aridity in the Central and Southern Pannonian Basin

For the investigation of geographical, monthly, seasonal, and annual distributions of aridity and its annual trend in the region of the Central and Southern Pannonian Basin (CSPB), which includes the territories of Hungary and Vojvodina (Northern Serbia), the De Martonne Aridity Index (DMAI) was used. The DMAI was originally calculated from a total of 78 meteorological stations with the maximum available time series of climatological data in three cases: 1931–2017 for Hungary; 1949–2017 for Vojvodina; and 1949–2017 for Hungary and Vojvodina jointly. The Palmer Drought Severity Index (PDSI) was used to control the DMAI results. Temperature and precipitation trends were also investigated to understand their effects on the aridity trend. Three aridity types are distinguished on the annual level, five on the seasonal level, and four on the monthly level. The annual aridity had no trends in all three periods. It seems that aridity can be considered a more stable climate indicator of climate change than the temperature, at least in the CSPB.

Independent Aridity and Drought Pieces of Evidence Based on Meteorological Data and Tree Ring Data in Southeast Banat, Vojvodina, Serbia

In this study, aridity data and tree ring data were collected in Northern Serbia, in Southeast (SE) Banat, a subregion within Vojvodina, and Vojvodina at large. They were each investigated independently. The De Martonne Aridity Index and the Forestry Aridity Index are derived from examining the relationship between precipitation and surface air temperature data sets sourced from seven meteorological stations in SE Banat, and from 10 meteorological stations located in Vojvodina as a whole. Vojvodina is a large territory and used as the control area, for the period 1949–2017. The Palmer Drought Severity Index was derived for the period 1927–2016, for both SE Banat and the totality of Vojvodina. The results of the Tree Ring Width Index were obtained from samples collected in or around the villages of Vlajkovac and Šušara, both located in SE Banat, for the period 1927–2017. These tree ring records were compared with three previous aridity and drought indices, and the meteorological data on the surface air temperature and the precipitation, with the objective being to evaluate the response of tree growth to climate dynamics in the SE Banat subregion. It was noted that the significant positive temperature trends recorded in both areas were too insufficient to trigger any trends in aridity or the Tree Ring Width Index, as neither displayed any change. Instead, it appears that these climatic parameters only changed in response to the precipitation trend, which remained unchanged during the investigated period, rather than in response to the temperature trend. It appears that the forest vegetation in the investigated areas was not affected significantly by climate change in response to the dominant temperature increase.