榆林沙区樟子松物候观测

Phenological Observation of Pinus Sylvestris in the Desertified Lands of Yulin

对榆林沙区樟子松进行了连续3 a的物候观测,结果表明,在榆林沙区樟子松历经3 a完成1个物候周期。4月上中旬芽生长,4月中下旬至6月上中旬枝生长,4月中旬至6月中下旬针叶生长,4月中下旬至5月上旬雄球花产生、散粉,4月底至5月上旬雌球花授粉,5月上旬至7月上旬幼果形成、生长,2年球果9月底至10月初成熟。不同立地、林分生长的樟子松单株物候具有差异性。日平均温度和活动积温是影响物候期出现时间及持续时间的重要因素。

The phenological observations of Pinus sylvestris in the desertified lands of Yulin had been conducted for 3 consecutive years.The results showed that Pinus sylvestris in the desertified lands of Yulin completed a phenological period by 3 years.The buds grew in the early and middle of April,branches grew from mid-to-late April to the early and middle of June,needles grew from mid-April to mid-to-late June,male cones were produced and pollinated from mid-to-late April to early May,female cones were pollinated at the end of April and early May,young fruits formed and grew from early May to early July,the two-year cones matured at the end of September and early October.The individual phenology of Pinus sylvestris grown in different sites and forests were different.Daily average temperature and active accumulated temperature were important factors that affect the appearance and duration of the phenological period.