杨树和榆树的种子在春末成熟。在罗斯托夫省,杨树和榆树的种子的散落期通常在五月份。据许多作者观察,乔木树种的始花期与有效积温有一定的关系。那么杨树和榆树的种子的散落期与温度有什么关系呢?作者曾在诺沃契尔斯克市及其郊区进行了物候期观察。观察的对象是20—40年生的 Poplar and elm seeds mature in late spring. In the province of Rostov, poplar and elm seeds usually fall in May. According to many authors, the initial flowering season of arbors and trees has some relationship with the effective accumulated temperature. So what is the relationship between temperature and the scattered period of poplar and elm seeds? The author conducted phenophase observations in Novosiksk and its suburbs. The object of observation is 20-40 years old