| Forests provide herbivores with the necessary elements such as food and shelter.Animals have formed a relatively stable phenological synchronization pattern with forest plants in the long-term evolutionary process.The phenological coordination of animals and plants is an important foundation to maintain the function and stability of communities and ecosystems.Phenology of forest leaf and moulting of roe deer are sensitive to the response of climate change,and their phenological changes are easy to be observed.Therefore,they are important and ideal sensors for studying the impact of climate change on phenology.Selecting the camera trap data from 2013-2019 in Hunchun area,the key parameters of forest leaf phenology and moulting of roe deer extracted and explored the annual trend of these two parameters.Choosing the meteorological data corresponding to the key phenological period,this research determined the length of optimal period(LP)of the meteorological factors affecting the change of the phenological period using the correlation analysis method.Besides,we used univariate regression and multiple regression analysis to analyze the impact of meteorological factors on forest leaf phenology in Hunchun area.Finally,the pairwise cross-wavelet analysis of forest leaf phenology,moulting of roe deer,temperature and sunshine duration were carried out to explore the relationship among meteorological factors,roe deer moulting,and forest leaf phenology.The main results were as following:(1)From 2013 to 2019,the overall start of leaf stretch period was in late April and early May in Hunchun area,it reacheed its peak in late May and early June,and basically ended in mid-June.It started the deciduous period in the late August,reached its peak in mid-September,and ended in mid-October.(2)In Spring,start of roe deer moulting was in late April,and finished in early June;In autumn,start of roe deer moulting was in mid-August and late August,and finished in late September and early October.(3)The start of growth season of forest leaf phenology in Hunchun area showed an earlier trend at an average rate of 1.18 days/year,the end of the growth season was delayed at an average rate of 1.54 days/year,accordingly the length of the growth season was prolonged;In spring,the start of roe deer moulting showed an earlier trend at the rate of 0.32 days/year,the end time of moulting is advanced at a rate of 1.21 days/year;In autumn,the start of roe deer moulting is delayed at a rate of 1.07 days/year,and the end of moulting is advanced at a rate of 1.11 days/year.(4)The average temperature during the optimal period was significantly negatively correlated with the start of the growth season,the average temperature during the optimal period was significantly positively correlated with the end of the growth season,whereas the average precipitation during the optimal period was significantly negatively correlated with the end of the growth season.(5)The average sunshine duration from winter solstice to the start of roe deer moulting in spring was significantly negatively correlated with the start of roe deer moulting,and the sunshine duration in October was significantly positively correlated with the end of roe deer moulting in autumn.(6)There is a high synchronization between forest leaf phenology and roe deer moulting,and the time lag between roe deer moulting,forest leaf phenology and periodic changes in temperature is more consistent,however,the time lag with periodic changes in sunshine is a trendendcy to shorten gradually. |
