Effect of Temperature on Frost-Free Days and Length of Crop Growing Season across Southern Ontario

Climate change has an impact on various climatic variables. In this study our focus is mainly on temperature characteristics of climate parameter. In temperate and humid regions like southern Ontario, the effect of climate change on Frost-free days in winter is distinctive. The average annual temperature is going upward but the extreme increase is in the winter temperature. Winter average temperature is going up by about 2˚C. However, extreme daily minimum temperature is going up by more than 3˚C. This climate effect has a great impact on the nature of precipitation and length of frost-free days. The snowfall over winter months is decreasing and the rainfall is increasing. However, the number of frost-free days during late fall months, early winter months, late winter months and early spring months are increasing. This result reveals an increase in length of the growing season. This research focuses on the effect of change in climatic variables on Frost-free days in Southern Ontario. Therefore, special attention should be given to the effect of change in climate Frost-free conditions on length of crop growing in winter season for potential investigation.

Soil Respiration Characteristics and Its Relationship with Environmental Factors of Different Vegetation Types during Growing Season in Dongting Lake

In order to ascertain the soil carbon flux characteristics of poplar plantations and crop communities in the Dongting Lake area during the growing season and their correlation with hydrothermal conditions,soil respiration rate was monitored at fixed sites and time points with an LI-8100 A automated soil flux system.Meanwhile,the surface temperature and soil temperature and humidity were measured. The soil respiration variation in the two different vegetation types and its correlation with environmental factors were analyzed. The results showed that in the growing season,the diurnal variation curves of soil respiration rate in the two different vegetation types showed a single peak variation,but there was certain difference in the appearance time of the peak. The peak of the crop appeared around11: 00 am,while the peak of soil respiration in the poplar appeared around 13: 00. The soil respiration rate of the poplar was also significantly higher than that of the crop,and the average difference of soil respiration rate between the two was 3. 09 and 3. 55 μmol/( m^2·s) in April and August,respectively. Temperature and soil moisture were the main factors affecting soil respiration of the poplar plantation and crop community. Temperature had a greater effect on the soil respiration of the crop community,and soil humidity had a greater impact on soil respiration in the poplar plantation,showing a correlation coefficient reaching 0. 952.

Impact of Climate Warming and Drying on Crop Growing Season in Northwestern Liaoning

Based on the observation data of the average temperature and precipitation of 8 national meteorological stations in the northwest region of Liaoning Province from April to October during 1961-2015,methods such as linear trend estimation,moving average,standard deviation and Mann-Kendall test are used to analyze the characteristics of average temperature and precipitation during the crop growing season in northwestern Liaoning.The results show that the average temperature during the crop growing season in the study area showed an upward trend,and the climate tendency rate was 0.193 ℃/10 a( P < 0.01).The largest contribution rate to temperature increase was in September,with a climate tendency rate of 0.27 ℃/10 a;the smallest contribution rate to the temperature increase was in July,with a climate tendency rate of 0.10 ℃/10 a.The warming trend was the most obvious in the second base year,with a climate tendency rate of 0.413 ℃/10 a( P < 0.01).The temperature was the lowest in the 1970s and the highest in the 2010s.The warming trend changed suddenly in 1996,and the sudden change reached a significant level of α = 0.05 after 2002.Precipitation was generally decreased,and the climate tendency rate was -7.68 mm/10 a.The decrease in precipitation was the most in July,and the climate tendency rate was -12.08 mm/10 a.The average temperature in the four base years failed to pass the correlation significance test.Among them,it showed an increasing trend in the second and third base year and a decreasing trend in the first and fourth base year.Rainfall was the highest in the 1960s and the lowest in the 1980s.After the abrupt change in 2002,precipitation decreased significantly.The research results provide reference for effective utilization of climate resources,rational adjustment of agricultural planting structure,and improvement of ecological environment quality.

Variations of the thermal growing season during the period 1961–2015 in northern China

Researching into changes in thermal growing season has been one of the most important scientific issues in studies of the impact of global climate change on terrestrial ecosystems. However, few studies investigated the differences under various definitions of thermal growing season and compared the trends of thermal growing season in different parts of China. Based on the daily mean air temperatures collected from 877 meteorological stations over northern China from 1961 to 2015, we investigated the variations of the thermal growing season parameters including the onset, ending and duration of the growing season using the methods of differential analysis, trend analysis, comparative analysis, and Kriging interpolation technique. Results indicate that the differences of the maximum values of those indices for the thermal growing season were significant, while they were insignificant for the mean values. For indices with the same length of the spells exceeding 5°C, frost criterion had a significant effect on the differences of the maximum values. The differences of the mean values between frost and non-frost indices were also slight, even smaller than those from the different lengths of the spells. Temporally, the starting date of the thermal growing season advanced by 10.0–11.0 days, while the ending dates delayed by 5.0–6.0 days during the period 1961–2015. Consequently, the duration of the thermal growing season was prolonged 15.0–16.0 days. Spatially, the advanced onset of the thermal growing season occurred in the southwestern, eastern, and northeastern parts of northern China, whereas the delayed ending of the thermal growing season appeared in the western part, and the length of the thermal growing season was prolonged significantly in the vast majority of northern China. The trend values of the thermal growing season were affected by altitude. The magnitude of the earlier onset of the thermal growing season decreased, and that of the later ending increased rapidly as the altitude increased, causing the magnitude of the prolonged growing season increased correspondingly. Comparing the applicability of selected indices and considering the impacts of frost on the definitions are important and necessary for determining the timing and length of the thermal growing season in northern China.

Projections of the Advance in the Start of the Growing Season during the 21st Century Based on CMIP5 Simulations

It is well-known that global warming due to anthropogenic atmospheric greenhouse effects advanced the start of the vegetation growing season （SOS） across the globe during the 20th century. Projections of further changes in the SOS for the 21st century under certain emissions scenarios （Representative Concentration Pathways, RCPs） are useful for improving understanding of the consequences of global warming. In this study, we first evaluate a linear relationship between the SOS （defined using the normalized difference vegetation index） and the April temperature for most land areas of the Northern Hemisphere for 1982-2008. Based on this relationship and the ensemble projection of April temperature under RCPs from the latest state-of-the-art global coupled climate models, we show the possible changes in the SOS for most of the land areas of the Northern Hemisphere during the 21st century. By around 2040-59, the SOS will have advanced by -4.7 days under RCP2.6, -8.4 days under RCP4.5, and -10.1 days under RCPS.5, relative to 1985-2004. By 2080-99, it will have advanced by -4.3 days under RCP2.6, -11.3 days under RCP4.5, and -21.6 days under RCP8.5. The geographic pattern of SOS advance is considerably dependent on that of the temperature sensitivity of the SOS. The larger the temperature sensitivity, the larger the date-shift-rate of the SOS.

Co-influence of the start of thermal growing season and precipitation on vegetation spring green-up on the Tibetan Plateau

The climate in the Tibetan Plateau(TP)has undergone significant change in recent decades,mainly in thermal and water conditions,which plays a crucial role in phenological changes in vegetation spring phenology.However,how the start of the thermal growing season(SOS-T)and the start of the rainy season(SORS)as key climatic factors affect vegetation green-up remains unclear.Given that these factors characterize thermal and water conditions required for vegetation green-up,this study investigated changes in the SOS-T and SORS from 1961 to 2022,using observation-based datasets with long time series.We found that the SOS-T and SORS have advanced across the TP in 1961-2022 and have shown a spatial pattern of advancement in the east and delay in the west in 2000-2022.Further,the co-effect of temperature and precipitation change on the start of vegetation growing season(SOS-V)in 2000-2022 was observed.Averaged across TP,the SOS-V had an early onset of 1.3 d per decade during 2000-2022,corresponding to advanced SOS-T and SORS.Regionally,the SOS-V generally occurred nearly at the same time as the SOS-T in the high-altitude meadow region.A substantial delay in the SOS-V relative to the SOS-T was observed in the desert,shrub,grassland and forest regions and generally kept pace with the SORS.Furthermore,for 50%of the vegetated regions on the TP,inter-annual variation in the delay in the SOS-V relative to the SOS-T was dominated by precipitation change,which was profound in warm-climate regions.This study highlights the co-regulation of precipitation and temperature change in the SOS-V in different vegetation cover regions in the TP,offering a scientific foundation for comprehending the impact of climate change and prospects for vegetation phenology on the TP.

Spatio-temporal reconstruction of air temperature maps and their application to estimate rice growing season heat accumulation using multi-temporal MODIS data

The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity.To solve the critical problems of estimating air temperature(T a) and filling in missing pixels due to cloudy and low-quality images in growing degree days(GDDs) calculation from remotely sensed data,a novel spatio-temporal algorithm for T a estimation from Terra and Aqua moderate resolution imaging spectroradiometer(MODIS) data was proposed.This is a preliminary study to calculate heat accumulation,expressed in accumulative growing degree days(AGDDs) above 10 ℃,from reconstructed T a based on MODIS land surface temperature(LST) data.The verification results of maximum T a,minimum T a,GDD,and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels.Overall,MODIS-derived AGDD was slightly underestimated with almost 10% relative error.However,the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper.Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring,agricultural climatic regionalization,and agro-meteorological disaster detection at the regional scale.

西藏地区一种新的四季划分方法

利用西藏地区38个气象站点1981—2022年逐日气温资料,分析常用气候季节划分方法在西藏地区的适用性,指出各种季节划分方法的不足和局限,基于西藏物候和主要农作物生育期提出的季节划分气温阈值等指标,筛选出适于西藏地区的季节划分方法及气温阈值,分析了西藏地区的四季开始日和长短的变化特征。结果表明:(1)常用气候季节划分方法在西藏地区应用有一定的局限性,而西藏物候季节划分方法和生育期季节划分方法适用于西藏高原地区的农事活动。(2)基于阈值“6℃、15℃”“5℃、16℃”“6℃、16℃”和“6℃、17℃”分析典型气象站四季时间长度变化特征发现,改则冬季时间长度长于其他季节、察隅夏季时间长度长于其他季节,且拉萨、昌都、改则、察隅四季长度均呈现夏季上升和秋冬季下降的趋势。(3)拉萨和昌都的夏季平均气温进行突变检验发现两站分别于2011年和2017年出现突变,佐证了夏季阈值取17℃的合理性。(4)西藏新四季划分法指标为“6℃、17℃”,该指标划分西藏四季发现,夏季站点主要分布在雅鲁藏布江一线的较低海拔地区;春、秋季持续时间整体呈现西北部和南部偏短、中东部偏长的特征,夏季呈现中部偏长、四周偏短的特点,冬季与春秋季则相反;四季时空特征符合西藏地区实际情况。春、夏、秋、冬季平均开始日分别为3月21日、6月16日、7月25日、11月3日。

西藏原始墨脱冷杉林微气候特征

受印度洋暖湿气流的影响,墨脱高海拔地带分布了大量的以墨脱冷杉(Abies delavayi var.motuoensis)为主的原始湿润森林,开展森林微气候研究能够为高寒生态脆弱区的植被保护和生态建设提供理论依据。文章基于2020年墨脱喜荣沟(海拔2700 m)原始冷杉林林内外的微气候监测数据,对比分析了林内与林外温度、湿度及不同深度土壤温度的季节变化特征,探讨了植物的生长季长度及生长季期间的低温事件发生情况。结果表明:(1)气温日变化特征显示,林内日间气温比林外低0.2∼2.7℃,森林表现出降温作用;除夏季外,其他季节林内夜间气温比林外均高0.2∼1.2℃,森林表现出保温作用;从季节变化看,林内外气温最高值出现在8月,最低值在1月,但林内气温较林外更加稳定;(2)该区域相对湿度较高(>80%),且在不同季节均表现为林内>林外;(3)除冬季外,土壤温度日变化总体呈现与气温类似的日动态,但土壤温度明显滞后约2∼3 h,林内土壤温度总体低于林外;春夏两季不同深度的土壤温度表现为5cm>10cm>20cm,而秋冬两季越靠近地表土壤温度则越低;(4)基于气温定义的生长季长度为208天,明显低于基于土壤温度定义的生长季长度(256∼268天);(5)2020年,冷杉林内低温事件发生的频率、强度及持续时间分别为1 d、-0.03℃和1 h,分别比林外少(低)了6 d、0.86℃和7 h。上述研究表明,原始墨脱冷杉林具有明显的保温和缓冲低温事件影响的作用,因此在未来亚高山天然林的保护和管理中应加强对森林微气候的观测和研究,不断提升天然林对气候变化的潜在应对能力。

近59a柴达木盆地低温事件变化特征分析

利用1961~2019年柴达木盆地9个国家站冬季逐日温度和作物生长季(5~9月)温度资料,分析柴达木盆地低温事件变化特征。结果表明:(1)柴达木盆地冬季平均温度、最低温度和极端最低温度整体呈显著快速上升趋势,平均最低温度和极端最低温度空间分布呈西北低东南高。(2)低温事件频次呈显著减少趋势,空间分布总体呈北多南少,地区差异较大。15 a左右的振荡周期较为明显,在1994年发生突变。(3)60年代低温事件较多,之后随年代的增加而减少。(4)西藏高原-1指数和西藏高原-2指数是影响极端低温事件频次、活动积温距平A和各月平均气温距平和B的主要因素。

Changing Spring Phenology Dates in the Three-Rivers Headwater Region of the Tibetan Plateau during 1960–2013

The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season(SOS)based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer–Normalized Difference Vegetation Index data for 2000–13. We then reconstruct the SOS time series based on the temperature data for 1960–2013.The regional mean SOS shows an advancing trend of 1.42 d(10 yr)during 1960–2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d(10 yr)during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d(10 yr)] during 2000–13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region,during 2000–13.

基于温光效应的江淮地区一季稻稻米营养品质模拟模型

以江淮地区一季稻主栽品种“辐优17”为试验材料,采用分期播种试验,系统测定不同温光条件下稻米赖氨酸、蛋白质、直链淀粉以及脂肪含量等营养品质指标,建立基于温光效应的水稻稻米营养品质模拟模型,并利用独立试验资料对模型进行检验。结果表明:(1)水稻稻米营养品质含量与水稻生长发育过程中温度和光照条件密切相关,稻米赖氨酸、蛋白质、直链淀粉以及脂肪含量与水稻生长期内累计温光效应值呈正相关。(2)灌浆期累计温光效应值影响水稻灌浆过程和籽粒粒重积累过程,开花后累计温光效应值越高,籽粒灌浆过程越快,粒重积累持续时间越短。(3)温光效应模型对水稻稻米赖氨酸、蛋白质、直链淀粉以及脂肪含量的模拟,与传统的辐热积法和有效积温法相比,显著提高了水稻稻米营养品质预测精度。

Non-cropping period accounting for over a half of annual nitric oxide releases from cultivated calcareous-soil alpine ecosystems with marginally low emission factors

草地农垦种植饲料作物,是高寒牧区的一种传统生产方式。而关于其一氧化氮(NO)排放特征与规律,目前知之甚少。本研究在青藏高原东北隅开展了饲料燕麦农田周年连续田间试验,对施肥(F)与对照(UF)处理的NO通量及主要环境因子进行了观测。结果表明:犁耕导致的排放占生长季排放量的54%–73%;非生长季占年排放量的51%–58%;年直接排放系数(EF_d)为0.021%±0.021%;施肥显著降低NO排放的温度敏感性(p<0.01);土壤水热条件和碳氮底物浓度共同解释NO通量变异的72%(p<0.01)。EF_d值可能主要取决于施基肥后一段时间(10 d左右)内的土壤湿度水平,需进一步研究来证实。

1960—2020年黄河流域气候生长季时空演变及成因分析

基于1960—2020年黄河流域89个气象站点资料,采用Mann-Kendall突变检验、Morlet小波分析和相关分析等方法对黄河流域生长季始期(GSS)、生长季末期(GSE)、生长季长度(GSL)、生长季内≥10℃活动积温(AT10)和≥10℃活动积温天数(DT10)的时空变化特征及其影响因素进行了分析。结果表明:(1)1960—2020年黄河流域GSS显著提前[-2.04 d·(10a)^(-1)],GSE呈推迟趋势[0.85 d·(10a)^(-1)],GSL显著延长[2.88 d·(10a)^(-1)],但区域差异较大,下游GSS开始最早(2月23),上游最晚(3月30),上游GSE结束最早(10月24),下游最晚(11月30),下游GSL最长为334.03 d,上游最短为297.33 d。(2)近61 a黄河流域GSL的显著延长主要源于GSS的显著提前。(3)近61 a来黄河流域生长季指标存在28 a左右的周期变化,GSS、AT10和DT10于1998年发生突变,GSL于2002年发生突变。(4)黄河流域上、中、下游地区生长季指标变化趋势一致,下游地区变化幅度最大,上游地区次之,中游地区变幅最小。(5)相关分析表明,近61 a来黄河流域GSS提前主要与春季升温有关,GSE延迟主要源于秋季增温,上游和下游地区GSL延长主要源于春季增温,中游地区GSL延长主要与秋季变暖有关。

基于FY-3D MERSIⅡ数据的辽宁省作物生长季日平均气温估算方法比较

作为反映气候特征的重要指标之一,日平均气温在农业气象灾害监测和气候变化研究等领域承担着至关重要的作用。与传统日平均气温的监测和估算方式相比,遥感技术具有全方位、宏观、动态等不可比拟的绝对优势,能够准确地描述日平均气温的空间异质性。为提高农业服务质量,保证农业健康、可持续发展,探索作物生长季日平均气温遥感反演方法,提高农业气象灾害监测精确度,以FY-3D MERSIⅡ遥感数据为基础,提取研究区日间地表温度(LST_(day))、夜间地表温度(LST_(night))、归一化植被指数(NDVI),同时还考虑了高程(DEM)、坡度(Slope)两个变量,结合气象站日平均气温数据,分别构建多元线性回归和随机森林日平均气温遥感反演模型,开展辽宁省2021年作物生长季(5—9月)日平均气温遥感监测的应用研究。结果表明:(1)基于多元线性回归模型反演的日平均气温均方根误差(RMSE)为1.71℃,平均绝对误差(MAE)为1.45℃;基于随机森林反演误差RMSE为1.17℃,MAE为0.96℃;整体上,随机森林的日平均气温反演结果更好,适用性更强。(2)实验当天和前1 d的降水总量对日平均气温的估算结果具有很大影响,降水量随时间的变化曲线与日平均气温的反演误差散点分布情况基本一致,呈现降水总量越大,日平均气温的反演误差越大的趋势,日平均气温反演结果受大气水汽含量的影响很大。(3)对输入的气温影响因子的重要性进行动态的统计分析,发现LST_(day)和DEM是日平均气温反演时两个最重要的变量,且LST_(day)对日平均气温反演的影响最为重要,但是随着作物的生长,DEM的重要性也越来越凸显。

2001—2020年蒙古高原昼夜非对称变暖对植被返青期的影响

基于2001—2020年归一化植被指数(NDVI)、增强型植被指数(EVI)2种遥感植被指数以及蒙古高原94个气象站点的月最高、最低温和降水量数据,利用累积NDVI的Logistic曲线曲率极值法和动态阈值法2种物候识别方法提取蒙古高原植被返青期,分析蒙古高原昼夜非对称变暖的时空变化及其对植被返青期的影响。结果表明:(1)2001—2020年蒙古高原生长季开始前6个月(上一年11月—当年4月)平均最高温[0.7℃·(10a)-1]和最低温[0.3℃·(10a)-1]均呈上升趋势,最高温的变暖速率是最低温的2.3倍。(2)季前昼夜非对称变暖对植被返青期均产生提前作用,但与最高温相比,最低温对返青期的影响程度更大,且影响范围更为广泛。(3)季前昼夜非对称变暖对不同植被类型返青期产生不同影响,白天变暖对灌丛、农田和稀疏植被返青期的影响更明显,夜间变暖对森林和草地返青期的影响更强,特别是森林地区(25.5%)。研究白天和夜间非对称变暖对蒙古高原植被物候的影响,对揭示温度对春季植被物候的影响机制有重要意义。

气候变化背景下河北夏玉米生长季热量资源利用率时空变化

探究夏玉米生长季热量资源利用率的时空分布特征,可为夏玉米品种布局调整、保障高产稳产提供理论依据。基于河北省夏玉米主产区15个农业气象观测站1981—2019年逐日气象数据、玉米及后茬轮作小麦的发育期观测数据,利用回归分析及空间插值等方法,分析气候变化背景下夏玉米生长季热量资源利用率时空变化。结果表明,1981—2019年河北省夏玉米潜在生长日数无显著变化、潜在积温显著增加(P<0.05);生长季热量资源利用率显著增加(P<0.05),生长日数利用率从1981年的80.4%提高到2019年的94.5%,积温利用率从1981年的84.5%提高至2019年的94.9%。河北地区夏玉米潜在生长季日数、潜在积温呈现南多北少的空间分布;生长日数利用率及积温利用率整体呈现南低北高的分布特征,其中廊坊地区生长日数利用率及积温利用率均较高(95%以上),邯郸生长日数利用率较低(85%以下)。1981—2019年夏玉米花前积温与花后积温气候倾向率分别为19.6、58.7℃·d·(10 a)^(-1),花后积温的上升速度明显高于花前积温,积温比呈现明显下降趋势,从1981年的1.6下降到2019年的1.1,下降28.5%。研究表明冀南地区夏玉米气候资源利用率仍有一定的提升空间,可以选用生长季更长的中熟和晚熟品种,育种或栽培上可选择灌浆阶段更长的品种,充分利用生长季热量条件,提高玉米产量。

蒙古国冬春季气候非对称变暖及其对植被返青期和春季NDVI的影响

基于2001—2020年NDVI和EVI两种遥感植被指数及蒙古国60个气象站点的气温和降水数据,利用累积植被指数的Logistic曲线曲率极值法和动态阈值法提取蒙古国植被返青期,并结合偏相关分析方法探讨二者与冬春季昼夜气温非对称变化之间的关系。结果表明:(1)近20 a来,最高气温在冬春季的变暖速率分别为0.07℃·a^(-1)、0.15℃·a^(-1)(P<0.05,R^(2)=0.33),最低气温在冬春季的变化速率分别为-0.01℃·a^(-1)、0.04℃·a^(-1),冬春季气温日较差的变化速率分别为0.08℃·a^(-1)、0.11℃·a^(-1)(P<0.05,R^(2)=0.52),存在明显的季节性差异。(2)蒙古国植被返青期对冬春季气候变暖的季节性响应是非对称的,冬季最高气温和气温日较差的影响大,而春季则是最低气温影响大,且均表现为负相关。(3)蒙古国气候变暖对植被NDVI产生的非对称影响主要表现在春季,即春季最高气温和气温日较差对植被NDVI主要表现为负相关,而春季最低气温对植被NDVI主要表现为正相关。研究结果可为进一步了解全球气候变暖背景下植被春季物候及植被后期生长的季节性影响提供重要参考价值。

呼和浩特地区土壤浅层温度变化特征及影响因素研究

地温是表征气候变化的主要气象要素之一,研究地温的变化特征有助于揭示地温对农业生产和生态环境的影响。利用呼和浩特地区1961—2020年生长季(4—9月) 5 cm、10 cm、15 cm、20 cm浅层地温观测数据,分析其土壤浅层温度的时间变化趋势,地温随土层深度的变化特征以及地温变化与气温、降雨量的关系。结果表明,呼和浩特地区生长季各浅层地温呈显著增温趋势,增幅为0.263~0.561℃/10 a,其中4月增幅最大;生长季地温随土层深度增加而下降。回归分析显示,浅层地温与气温、降雨量呈正相关关系,气温对浅层地温变化的解释贡献率为78%~85.91%,且达到极显著水平(P<0.001);降雨量对浅层地温变化的解释贡献率为3.72%~11.54%。多元回归分析显示,气温与土壤浅层地温的关系比降雨量更加密切,更能直接影响浅层地温的变化。