Simulation On Potential Spatial Distribution Of Winter Rapeseed In North China

Rapeseed is one of major oil crops in China.With climate change, progress ofrape cultivation technique and release of new varieties, the growth, yield and qualityand planting structure of winter rapeseed gradually is changing. Since winterrapeseed planting divisions has not fully reflected the practical condition of rapeplanting. At present, cultivation of winter rapeseed in northern has been doneabundant valuable researches on micro scale focusing on experimental science. Theyselected the stronger auto-cold ability of winter rapeseed to improve the yield andquality of rapeseed. Winter rapeseed to move north has made some progress with animportant impact on agriculture in the north. Meanwhile, this result can bring newchance and challenge for the development of oilseed rape industry. Analysis of therelationship between the northern area of winter rapeseed planting distribution andclimatic conditions, division of winter rapeseed planting climatic suitability regionwill improve the distribution of production of winter rapeseed, reasonably adjust theagricultural production structure and plantation structure and promote agriculturalproduction in northern area to realize the planting of winter rapeseed region innorthern area and protect the national edible oil supply security. It has importantpractical significance to promote the sustainable development of ecologicalenvironment in northern area.In this study, based on different periodical planting data of winter rapeseed anda long sequence of climate data. Building spatial database of meteorological factor.and setting up species distribution model by GIS technogy, the small scale of fieldsample test results of typical ecological point is extended to simulate regional scalespace. Analysis of the relationship between the winter rapeseed planting distributionand climate conditions to determine the main meteorological factors about affectingthe northern winter rapeseed planting distribution, simulate the probability ofpotential spatial distribution of winter rapeseed in north area, and divises suitableplanting area of winter rapeseed Northern, evaluate the northern boundary of winter rapeseed planting. The main conclusions in this paper are as follows:1. Winter rapeseed planting in north area is feasible.The probability distribution region of potential space of winter rapeseed is0-0.97in north. The regional disparity of northern climate affect the distribution ofwinter rapeseed potential space directly, limited by climatic conditions in mostregions of cultivation in the northeast region and the Qinghai Tibet area probabilityis very small. On the contrary, the probability of winter rape planting in the northernregion of Shanxi, the northwestern region of Hebei and in the northwestern ofShanxi and Gansu is very large. It shows that winter rapeseed in the northern area iscompletely feasible.2. Winter rapeseed planting in north area have great capabilities.Winter rapeseed planting in north area is divided into four levels: they are theoptimum area, suitable area, less suitable area, unsuitable area.(1) The optimum area. Located mainly in the southeast of Gansu, southernNingxia、Shanxi、Hebei、Shanxi in the mid-south and Beijing、Tianjin. its area is56.99million km2; this region altitude below4800m, the annual averagetemperature6.7℃to11.9℃, extreme low temperature-16.6℃to-9.5℃, negativeaccumulated temperatures-447℃to-164℃, precipitation is moderate, the heatcondition is superior, appropriate temperature, as the result, winter rapeseed canoverwinter safely, is the most suitable planting area of winter rapeseed in northernarea, suitable for the cultivation of cold hardiness of winter rapeseed.(2) The more suitable area. Located mainly in South Central Tibet, Qinghaisoutheast, mid Gansu and Hexi Corridor, Ningxia around Yinchuan, northern Shanxiand southern Liaoning, its area is126.23million km2; this region altitude below5700m, the annual average temperature5.1℃to10.3℃, extreme low temperature-18.3℃to-14.3℃, negative accumulated temperatures-657℃to-303℃, is thesuitable district to plant.(3)The less suitable area. Mainly distributed in southern Jilin, northernLiaoning, Western Inner Mongolia, Gansu West Hexi Corridor, East Xinjiang, Qinghai around Xining, its area is189.87million km2; this region altitude below6300m, the annual average temperature2.8℃to9.7℃, extreme low temperature-21.8℃to-16.9℃, negative accumulated temperatures-853℃to-497℃, theindividual area of winter rapeseed winter freezing often occur when this time,suitable for planting the super cold hardiness of winter rapeseed.(4) The unsuitable area. Mainly distributed in Heilongjiang, Middle Westregion of Inner Mongolia, northeast Jilin, Western Qinghai and Northern Tibet, itsarea is about314.91million km2. The area has high altitude, dark climate, the annualaverage temperature≤3.4℃, extreme low temperature≤-20.9℃, negativeaccumulated temperatures≤-800℃, The seeding will die overwintering if morethan planting line.More than50%other areas can plant winter rapeseed except Xinjiang, Tibet,some cold plateau and plateau sub Frigid Zone in Qinghai and the northeast of innerMongolia and Heilongjiang cold regions. This result shows that the winter rapeseednot only can be planted, but also have good development potential. It will set arecord in traditional planting division and change the structure of productiondistribution.3. Affecting the leading climatic factors of winter rapeseed planting distributionand its threshold.Affecting the leading climatic factors of winter rapeseed planting distributioninclude: negative accumulated temperature、the coldest mouth of the lowesttemperature、extremely low temperature、average annual temperature、the averagetemperature of the coldest month、≥0℃accumulated temperature、the precipitationduring crop growth stage. Northern winter rapeseed planting distribution probabilityis changing with range of different climate factor. Its growth needs proper heatcondition and moisture condition and the safety winter closeness to limitingcondition. Its threshold: negative accumulated temperature≥-800℃、the coldestmouth of the lowest temperature≥-25℃、the average temperature of the coldestmonth≥-15℃、average annual temperature≥2℃、extremely low temperature≥ -28℃、180mm≤the precipitation during crop growth stage≤280mm. Thethreshold simply reflects a single meteorological factor in the effect of general trendof winter rapeseed planting distribution. However, affecting the leading climaticfactors of winter rapeseed planting distribution has the diversity and complexity, thesingle factor, there are interaction and restriction. So in the practical application, thecritical value of each meteorological factor will change when we consider factoreffect synthetically4. The northern boundary of winter rapeseed planting northwardThe research simulate the arctogaea realm of winter rapeseed planting,generally speaking,southern Jilin, southern Inner Mongolia, southern Xinjiang asthe boundary, compared with the traditional winter rapeseed planting arctogaea, itpushed northward about1200km,latitude from N39°to N45°，to prove the winterrapeseed planting northwards is feasible. This result shows that with climatechange、progress and release of new varieties of rape cultivation, the winter rapeseedplanting distribution is changing. Winter rapeseed will become an important oil cropin northern area.