The Forest Health And The Technique Of Limestone Improvement On Acid Soil In Tieshanping, ChongQing

A series of studies was put into practice in Chongqing suffering from acid rains in 2006-2007. Intensive observations of above-ground and underground growth,the state of tree crown,root distribution ect.on evaluation the health degree of forest;In order to discern plants resistant to acid rain and Drought-stress.A field investigated contain pinus massoniana and Cinnaraomum camphora of wide scope on plant sensitivity to acid rains and drought was cayyied out;A location test was conducted to research on effects of different application doses of lime powder topinus massoniana's growing to above and Fine-root character.In order to estimate the optimization doses of limestone powder mixed,main results are as follows:1)This is a positively correlation(R_min²=0.7362)between the roots and above-ground status of individual tree.the growth status including height,diameter at breast height,needle biomass and Defoliation of individual tree.Through the fourth growth status of above-ground and unite the root biomass can comprehensive evaluation the effect of acid rains to pinus massoniana;several years continuous observation we found that:The defoliation ofpinus massoniana was content increased year by year.A closer inspection of the data reveals that The defoliation for the majority of the trees lies within the 25-60%interval.2000-2004 the ratio upwards 60 percent.2003 and 2004 the ration of defoliation within the 25-60%was 78.7%,77.5%respectively,the ratio 2005-2007 upward 75%. manewhile,the discoloration was serious,remaining at a high level,and have the increase trend. everything told us that thepinus massoniana at sub-health state.2)As a whole,respectively,and the order of distribution proportion ofpinus massoniana biomass in different organs is:tuuck(60.8%)＞branch(18.1%)＞root(10.2%)＞bark(7.2%)＞needle (3.7%).with the graveness of soil acidified,the different dominance grades ofpinus massoniana'root biomass represent a decreasing trend,and which wiil take others ingredient decrease.just as we know It is disadvantage for forest health,and the graveness acid rains haven brought a notable negative infection forpinus massonianas' biomass,especially the roots' biomass. 3)Study from the root distribution of Pinus massoniana,root mainly distribution in soil layer of 0-30cm,while Cinnamomum camphora and Sapium sebiferum's root main distribution in soil layer of 0-20cm.Which are teeter than Pinus massoniana's root distribution.the order of size of total dry weight,total length,total surface area,total volume and the total tip number of fine roots per unit area in 0-50cm soil layers was the pure stands of Sapium sebiferum＞the pure stands of Cinnamomum camphora＞the pure stands of Pinus massoniana,while the order of size of area of fine roots per unit area in 0-50 cm soil layers was the pure stands of Cinnamomum camphora＞the pure stands of Sapium sebiferum＞the pure stands of Pinus massoniana.As compared with the pure stands ofpinus massoniana.We found that:the pure stands's roots distribution is more equality and depther than the mixed stand's root distrbution,in the mixed stand Cinnamomum camphora is dominant status,the effect Cinnamomum camphora to pinus massoniana is bigger than pinus massoniana to Cinnamomum camphora,with the increase of soil layer depth the five physical index of roots characteristic manifest decreasing trend.Because roots main distribution in soil surfacc layer which is not advantage for roots to asbord more water and nutrient.It is disadvantage for forest health.Advance indicate the effect of acid rains and atmospheric pollution to pinus massoniana is very severity.especially for the tree ofâ…£grades.Which is susceptivity to acid rains and atmospheric pollution.4)The drought resistance was investigated for 13 main tree species at the Forest Park of Tieshanping,Chongqing,Mainly based on the comparison of mortality and defoliation,the investigated conclusion as following:Tree species with high drought-resistance included:Sapium sebiferum;Tree specics with relatively higher drought-resistance included:Liquidambarformosana, Phoebe sheareeni v.omeiensis;Tree species with moderate drought-resistance included:Lithocarpus glaber,Prunus,Mallotus barbatus,Toxicodendron verniciflua,Schoepfia jasminodora, Cinnamomum camphora,Cuninhama lanceolata,Pinus massoniana;Tree spccics with relatively lower drought-resistance included:Quercus fabri hance,Litsea mollis.Meanwhile,based on field concentrative investigation of 65 plants and the European defoliation percentage classification standard,Some plants with very strong resistance to acid rains included:Liquidambar formosana., Schima superba Gardn.et Champ.,Eucommia glyptostroboides Hu et Cheng.,Cinnamomum camphora.,Mallotus barbatus.,Ficus virens.,Machilus zuihoensis Hayata.,Lithocarpus glabe., Grebillea robusta cunn.,Viburnum odoratissimum Ker-Gawl.,Michelia alba DC.,Michelia maudiae.,Michelia chapensi.,Ficus microcarpa L.f.,Ficus altissima.,Erythrina variegata L., Cedrus deodara Loud.,Chimonanthus praecox(L.)Link,Ficus Goldenprincess.,Pittosporum tobira (Thunb.)Air,Sophora xanthantha CY Ma.,Platanus hispanica Muenchh.,Prunus.,Phoebe sheareeni v.omeiensis.,Pelargonium hortorum L.H.Bailey,Agave sisalana perrine ex Engelm..a plants with stronger resistance to acid rains included Citrus reticulata Blanco.5)Application lime power in acid soil indicates that:The pH-value of soil layers,whether mixed limestone powder or not,increases with soil depth firstly quickly,then slowly and finally reaches to a steady state.Before the treatment,a significant difference of soil pH-value exists only between the surface layer(0-10cm)and other deep layers(10-20,20-30,30-40,40-50 cm)(p＜0.05);while after the treatment a significant difference of soil pH-value exists between the two upper layers(0-10, 10-20 cm)and other deeper layer(30-40,40-50 cm)(p=0.006;p=0.013).Compared to the soil pH-value before treatment,the soil pH-value two years after the treatment was increased by 0.2-0.4 for different soil layers.6)The characteristics of fine roots firstly increase and then decrease with soil depth in the research depth range before the treatment;while after the treatment in 2006 year showed a continuous increasing trend with soil depth.From the whole on,the characteristics of fine roots after the treatment showed a firstly increase and then decrease trend with increasing doses of limestone power, the best effect for the C treatment(392g/m³)with a distinctly promotion of fine root growth.The ratios of fine roots characteristics values before and after the treatment showed the same effect. Meanwhile,analyze the root(2-5mm)find that except dry weight root index d treament is higher than c treament,and other root indexs c treament are the highest,and the fine root response that the proper doses of liming is 392g/m³.7)The study of limestone additions on acidified soil indicate that:The diameter at breast height (DBH)growth rate of c(2t/hm²)treament handling of the highest,and with a(0t/hm²),b(1t/hm²) treatment Significant difference.2007 growth rate of d(3t/hm²)treament handling of the highest, and with a(0t/hm²)treatment Significant difference.and with others treament not Significant difference,as a whole,the function of a treament which produces effect to the tree diameter at breast height(DBH)is the smallest.The effect on the descend of defoliation c treatment's function is the most distinctness contrast to others treatments,combine the two years researched of defoliation,the tendency of the defoliation display reduces firstly then elevates with the doses increases of limestone power,the c treatment is the turning point;by the investigation found this is remarkable significant influence to the growth of Schima superba Gardn.et Champ after appliation limestone powder in acidfication soil and the function to growth of Schima superba Gardn.et Champ c treatment is the biggest in 2006 year.and with b,c,d treatments have Significant difference(p＜0.05).While 2007 year carried on the investigation found that d treatmengs of limestone power btought remarkable significant to growth of Schima superba Gardn.et Champ.8)Through the analysis found that:2007 year the biggest numerical value of five characteristics of fine roots aroused by d treatment contrast to others treatment,and the analysis of variance whir a,e teatments have a significant difference(p=0.036,p=0.047).At the same time,analysis found the background data of 2004 year of the five characteristics of free roots not have an impact on the 2007's.on the conclusions that,the fine root characteristics of 2007 year manifest differences as a result of the different limestone powder doses.It also shows that the d treatment is the propest dose of liming,Bring the most prominence effects to the fine root growth.