| Plant functional traits reflected the response of plants to the changes of living environment,and also had a certain impact on ecosystem functions.The Loess Plateau was one of the most serious areas of soil erosion and ecological damage in the world,while afforestation was considered to be one of the most effective ways to prevent soil degradation,improve the ecological environment and promote the restoration of degraded ecosystem.During the implementation of the project,the micro topography(such as slope aspects,slope graident)of the plateau was obviously different,which makes a large area of afforestation affected by these micro topography.Therefore,it had great significance to study the relationship between leaf fountional traits and microhabitats.In order to study the response characteristics of plant leaf characteristics to micro environment changes in typical forest areas of conversion of farmland to forest on the Loess Plateau.The effects of sunny slope(including half sunny slope)and shady slope(including half shady slope)and three slope gradient(15°~20°,21°~25°,and 26°~30°)on the leaf functional traits of apricot(Prunus armeniaca L.),the main afforestation tree species on the Loess Plateau,was explored in this study.The results showed that:(1)The changes of leaf functional properties with slope aspect and gradient in the study area as follows: On the slope aspect,the changes of leaf functional properties were different in different slope aspect and slope gradient,the dry matter content,specific leaf weight and water content of leaves gradually increase from sunny slope to shady slope,and the specific leaf area showed the opposite trend.On the slope gradient,the specific leaf area and leaf area decreased first and then increased with the increase of slope gradient,while the dry matter content of leaves was opposite;The specific leaf weight and leaf water content decreased with the increase of slope gradient.It shows that plants had different adaptive strategies in different habitats;(2)The changes of soil nutrients with slope aspect and slope gradient in the study area as follows: Soil organic carbon,total nitrogen,total phosphorus,available nitrogen,available phosphorus and water content were higher in the shady slope than in the sunny slope.On the slope gradient,it showed a trend of increasing with the increase of slope gradient,among which,soil organic carbon,total nitrogen,totalphosphorus and available phosphorus were the highest in 26° ~ 30°,soil available nitrogen was highest in 21°~25°,and soil water content was highest in 15°~20°.(3)The relationship between plants and soil nutrients in the study area as follows:On the slope aspect,soil organic carbon,soil temperature and soil total phosphorus content were the main factors affecting the change of Apricot Leaf functional traits;on the slope gradient,soil total nitrogen,soil water content and soil total phosphorus content were the main factors affecting the chang of Apricot Leaf functional traits.(4)The correlation between the leaf functional traits of the apricot in the study area: Specific leaf area were significantly negatively correlated with leaf dry matter content,leaf water content and Leaf Mass per Area,but it was significantly positively correlated with leaf water content;leaf dry matter content were significantly positively correlated with leaf water content and Leaf Mass per Area,but it was significantly negatively correlated with leaf area;leaf water content were significantly positively correlated with leaf area and Leaf Mass per Area;leaf area was significantly negatively correlated with Leaf Mass per Area.(5)In this study area,the slope aspect and slope gradient had an importmant impact on the leaf functional traits and its soil nutrients,while the interaction between them only had an importmant impact on the leaf water content,and it had an importmant impact on soil nutrients.These results show that environmental factors such as soil water content,soil nitrogen content,soil phosphorus content,soil organic carbon content,and soil temperature had changed along slope aspect and slope gradient,forming a microhabitat.Therefore,the apricot leaf functional traits made differences between slope aspect and slopes gradient,it reflecting the competition and adaptation mechanism of plants in the microhabitat.Therefore,studying the response of plant leaf fountional traits to changes in microhabitats,selecting terrains with sufficient soil nutrients can provide help to protect the main afforestation tree species and sustain the ecological benefits of the returning farmland to forest areas,and provide scientific guide for local vegetation restoration and sustainable ecosystem construction. |
