| The Physiological integration,an ecological strategy of the clonal plants coping with the heterogeneous habitats,has been attracted intensive concern by ecologists.However,there are few of research related to the structural characters and integration dynamics for clonal plant integrated Physiological units(IPUs).Moreover,the effect of clonal integration on clonal growth and population structure is unclear.In this paper,the heterogeneity habitat-limestone mountain act as the research area,and clonal plant--Phyllostachys glauca is chose as tae research object.The stable isotope 15N in situ tracing technique was used to describe the structure of the population of Ph.glauca and its clonal integration spatio-temporal pattern.The aim of adopting 'Latin square design'and using the method of cutting off the bamboo rizhome is to examine the results the effects of the clonal integration from different size of cutting rhizome clonal unit on Ph.glauca shoots growth and population structure.Additionally,the new model of efficient and sustainable management of Ph,glauca forest was explored based on the characteristics of clonal integration.The purpose of this study was to reveal the relationship between the structure and resource transmission of the Physiological integration of the Ph..glauca under the natural condition,and to analyze the importance of the clonal integration to the clonal growth of the Ph.glauca and the feasibility of applying the clonal integration in bamboo forest management.Eventually,this paper tries to explain the dynamic mechanism of clonal plant IPUs,and provide theoretical basis and technical support for the management of bamboo forest.The main results are as follows:(1)The age structure of Ph.glauca IPUs was 23.6%in 1a ramets,26.3%in 2a ramets,41.2%in 3a ramets and 6.2%in 4a ramets,which indicated that IPUs were Physiological units with high Physiological activity.The average range of clonal integration was 3.56 ± 2.79m2,and the effective distance of clonal integration was 3.18±0.96m.In addition,the shape of IPUs was irregular oval.The spatio-temporal pattern of clonal integration was as follows:after the exogenous 15N mark,the content of ?15N in the high,medium and low concentration grades increased first and then decreased,and reached the peak at the 4th and 5th week.The clonal integration area of different 15N marker concentration subspecies was gradually expanded around the mother bamboo,and the boundaries of IPUs became stable after one month.The 815N content of different organs changed to the highest of the aboveground leaves,the lowest in the ground,the highest in the underground part and the lowest in the rhizome,and the Ndff%content was the aboveground part leaves the highest,the lowest branch.The root absorption ability of the underground organs was the strongest,and the absorption capacity of the flagellum was the weakest.This indicates that in the process of growing bamboo,bamboo and bamboo root is not only the main "sink",but also the strongest absorption of the organ.(2)In the first year of the rhizome treatment(2015),1m2 broken rhizome unit of the bamboo shoot quantity is more,while the bamboo rate is the lowest.When the bamboo shoot diameter is less than 1cm,the plant height and breast diameter is much smaller than the other size of the broken rhizome unit.When the bamboo shoot diameter is more than 2cm,CK control treatment of bamboo shoot rate is the lowest,and the rate of bamboo is the highest.In the second year of the rhizome treatment(2016),the number of shoots produced by CK treatment was better than that of other treatments.25m2,6.25m2,2.8m2broken rhizome unit of the bamboo shoot qualtity was basically the same allm2 broken rhizome unit of the bamboo shoot quantity,and the shoot diameter was greater than 2cm.But the plant height and DBH of CK were still the largest,and the value of 1m2 broken rhizome unit was the smallest.There were some effects on the population structure of bamboo forest.Although the overall evenness of bamboo forest was up to standard,there was a great difference in the uniformity of the broken rhizome.CK treatment was better than other treatments.2.8m2,1m2 broken rhizome unit uniformity is not up to standard.After breaking the rhizome,the whole population of Ph.glauca forest was updated.However,because of the restriction of the clonal integration in the different size of the rhizome breaking unit,it has a negative influence on the clonal growth and population structure.CK control indicators are better than the overall different fault rhizome processing,which shows that the clonal integration has a positive effect on the clonal gro\Awth and population structure in the limestone mountain.(3)In this study,it was found that the diameter and plant height of the new bamboo shoots were significantly smaller than those of the bamboo leaves and the control,and within the bamboo shoots in the lm-5m section,the basal diameter and height of new bamboo are consistent with retention.After the shooting of bamboo,the basal diameter and plant height of clear cutting stand were significantly different from those of control forest and reserved stand.This indicates that after shooting bamboo,accepted the transfer of mother bamboo clonal integration of resources.All forests bamboo shooting in lm-5m diameter base number,plant height,forest and bamboo leaves were better than the control,and no significant difference with CK.It means that if the bamboo clonal integration of the maximum distance is 5m,the mother bamboo nutrient supply of the overall quality is better than the effective distance of Ph.glauca outside of bamboo shooting within the effective distance of bamboo shooting.In the actual "rotative belt cutting",the clear-cutting belt can accept the supply of resources on both sides,so "rotative belt cutting"clear cutting bandwidth within 10m is appropriate.In conclusion,the Ph.ysiological integration plays an important role in cloning and growth in limestone mountains bamboo,and the average size of clonal integration unit is 3.56m2.The effective integration distance of Ph.ysiological integration is up to 4.6m,and the age composition is mainly young bamboo.The 15N transmission in the IPUs is centred around the implant,and reaches the highest concentration at 4-5 weeks.Different size of broken rhizome unit in the growth and population structure of clone was inhibited,which indicated that clonal integration had an important positive effect on the growth in limestone mountains areas.Based on the clonal integration characteristics of Ph.glauca,the cutting mode of "rotative belt cutting" can save labor force and promote the continuous growth of bamboo forest,which is feasible in theory totally. |
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