| Cunninghamia lanceolata had an important position in the domestic plantation history of production for timber, but the actuality was common that the productivity descended and the woodland degraded after successive planting of Cunninghamia lanceolata. Therefore, the problem about sustainable productivity of site for plantation of Cunninghamia lanceolata had attracted more attention. Many scholars believed that scientific planting of Cunninghamia lanceolata could achieve sustainable management of the plantation, and would not cause the woodland degradation. There was a common thought that rotative and mixed planting was advantaged to improve site and productivity. Because of the long growth cycle of forest, and that the effect of planting mode usually appeared after 10 years or decades, coupled with the variability of woodland environment causing the heterogeneity of soil fertility, the studies were not going deep into the evolvement of site, and the storage and transfer of Al and nutrition in the ecosystem, especially that of microelement after rotative planting in the field of successive planting of Cunninghamia lanceolata.There has little relevant reports about these studies. The plot was in the productive center of Cunninghamia lanceolata, Xiqin forestry center, in Nanping county, Fujian province. There were 30 a of Cunninghamia lanceolata forests of the third generation where Cryptomeria fortunei and Phoebe bournei was planted after the second generation Cunninghamia lanceolata felling down (hereinafter referred to as the Cryptomeria fortunei forest and the Phoebe bournei forest, respectively). This studies were about community structure, biomass allocation and productivity, soil fertility, litters remain and return, litters decomposition rate; remain and return amount of nutrient and Al; decomposition rate, releasing characteristics, spatial distribution and biological cycle of nutrient and Al for the forest which rotatively planted with Cryptomeria fortunei and Phoebe bournei after second generation plantation of Cunninghamia lanceolata compared with the third generation of Cunninghamia lanceolata (hereinafter referred to as the Cunninghamia lanceolata forest). The results were as follows.(1) The Cryptomeria fortunei forest had the most species diversity values in shrub layer, followed by Cunninghamia lanceolata forest, and the Phoebe bournei forest. The species richness values of undergrowth in Cunninghamia lanceolata and Cryptomeria fortunei forest were bigger than that of Phoebe bournei forest. The rank of the number of species and individuals in herb layer was Cunninghamia lanceolata forest>Cryptomeria fortunei forest> Phoebe bournei forest. The undergrowth in Cunninghamia lanceolata and Cryptomeria fortunei forest were rich, and that of Phoebe bournei forest developed badly.(2) The rank of biomass of standard tree, tree layer and the forest was Cryptomeria fortunei forest>Phoebe bournei forest>Cunninghamia lanceolata forest. The biomasses of tree layer in three forests were above 90% respectively. Net growth of the forest was Phoebe bournei forest> Cryptomeria fortunei forest>Cunninghamia lanceolata forest, and that of tree layer was as the same. It was very beneficial to management of timber forest.(3) The values of total porosity, non-capillary porosity, ventilating degree and ratio of non-capillary porosity/capillary porosity of the surface and middle soil layers in the stands after rotative planting were higher than that in the Cunninghamia lanceolata forest. The rank of maximum and minimum water holding capacity,and capillary water holding capacity was Phoebe bournei forest>Cryptomeria fortunei forest>Cunninghamia lanceolata forest, the rank of amount of water stable aggregates with size bigger than 0.25 mm and 1 mm was Phoebe bournei forest>Cryptomeria fortune forest>Cunninghamia lanceolata forest, and the rank of damage rate of soil structure was Cunninghamia lanceolata forest> Cryptomeria fortunei forest > Phoebe bournei forest. Rotative planting improved the quality of soil porosity and soil structure, and coordinated the contradiction of soil between water and gases. Soil nutrients had some complicated changes in different soil layers. After rotative planting, HA/FA, total exchangeable base cations of soil increased, and the quality of colloid was improved. The topsoil exchange of acid showed Phoebe bournei forest>Cryptomeria fortunei forest>Cunninghamia lanceolata forest, but that of middle soil and subsoil showed Cunninghamia lanceolata forest> Cryptomeria fortunei forest>Phoebe bournei forest, meaning that the rotative planting might reduce the potential acid. Although the average contents of Al and active Al in 0-60 cm soil layer were Phoebe bournei forest>Cryptomeria fortunei forest>Cunninghamia lanceolata forest, but the percentages of exchangeable Al and AI-hydroxy-poly with higher biological toxicity were higher were Cunninghamia lanceolata forest>Cryptomeria fortunei forest>Phoebe bournei forest, meaning that rotative planting reduced the Al hazards.(4) The remain amount of litters (including deadbranch and deadleaf) in Cryptomeria fortunei forest (8.72 kg/hm2) was more than that in Phoebe bournei forest (7.10 kg/hm2) and Cunninghamia lanceolata forest (7.18 kg/hm2). The amount of litters in non-decomposition layers were more than that in decomposition layers in the three forests. The bigger amount of deadbranch and deadleaf in Cunninghamia lanceolata and Cryptomeria fortunei forests than that in Phoebe bournei forest meant that the litters in Cunninghamia lanceolata and Cryptomeria fortunei forest had a strong persistent and lag characteristics. The total remain amount of C of litters was Cryptomeria fortunei forest> Cunninghamia lanceolata forest> Phoebe bournei forest. The total remain amount of Al of litters was Phoebe bournei forest (66.82 kg/hm2)> Cryptomeria fortunei forest (49.85 kg/hm2)>Cunninghamia lanceolata forest (22.45 kg/hm2), and nutrition storage was Cryptomeria fortunei forest (236.42 kg/hm2)>Phoebe bournei forest (224.37 kg/hm2)>Cunninghamia lanceolata forest (164.33 kg/hm2).(5)The total amounts of litters of Crypotomeria fortunei forest and Phoebe bournei forest were 2.18 and 1.56 times respectively of that of Cunninghamia lanceolata forest. The changing laws of annual litters return were different among the three forests. Cunninghamia lanceolata forest had only one maximum peak for litters (August), Crypotomeria fortunei forest had two maximum peak for litters (May and August), and Phoebe bourne forest also had one maximum peak for litters (April). The annual nutrition return amount by litters was Crypotomeria fortunei forest (274.37 kg/hm2)> Phoebe bournei forest (138.84 kg/hm2)>Cunninghamia lanceolata forest (104.75 kg/hm2). The amount of C was Crypotomeria fortunei forest>Phoebe bournei forest>Cunninghamia lanceolata forest, and that of Al was Crypotomeria fortunei forest> Cunninghamia lanceolata forest>Phoebe bournei forest. The return maximum peak 1 of C,N,P,K,Ca,Mg,Fe,Mn,C,Zn and Al in litters for Cunninghamia Lanceolata forest appeared in August; that of Phoebe bournei forest presented in April, and Crypotomeria fortunei forest was in May and August. The return pattern of C,N,P,K,Ca,Mg,Fe,Mn,Cu,Zn and Al in branch litters was the same as that of biomass of branch litters, the maximum peak of Cunninghamia lanceolata forest in August; that of Crypotomeria fortunei forest in May, and that of Phoebe bournei forest in August.(6)Decomposition of the litters was studied for one year. The results showed that the rank of the rate of the six litters's decomposition was Cunninghamia lanceolata leaves>Crypotomeria fortunei leaves>Phoebe bournei leaves>Cunninghamia lanceolata branches>Phoebe bournei branches>Crypotomeria fortunei branches. After la decomposition, C contents of Phoebe bournei branches enriched, and that of Crypotomeria fortunei branches didn't change, but C contents dropped in cunninghamia Lanceolata leaves, Cunninghamia Lanceolata branches, Phoebe bourneid leaves and Crypotomeria fortunei leaves. N was enriched in three leaves litterss and Phoebe bournei branches, but dropped in Crypotomeria fortune branches. The concentration of P increased in Cunninghamia lanceolata leaves and branches, and that of the other litters all descended. The concentration of K increased in Crypotomeria fortunei leaves, and that of the other litters all dropped. In the six litters, the contents of Mg all dropped. The concentration of Ca enriched in Phoebe bournei branches, but descended in other five litters. Microelements all increased in the six litterss except Mn in Phoebe bournei leaves. After a year of decomposition, the concentration of Al in the six litters all increased.(7)After a year of decomposition for litters, the remain rate of C in the six litters was Phoebe bournei branches>Crypotomeria fortunei branches>Cunninghamia lanceolata branches> Cunninghamia lanceolata leaves>Phoebe bournei leaves>Crypotomeria fortunei leaves, and all released. Except the remain rate of K in Crypotomeria fortunei leaves back to the original level, the macroelements of the other litters all released. The changes of remain rate for Fe,Cu,Zn were complex in the process of decomposition. The change extent of Mn was gently. Al enriched in the six litters after a year decomposing.(8)The most releasing amount of C was in Phoebe bournei forest, but that in Cunninghamia lanceolata and Crypotomeria fortunei forests were more close. The annual releasing amounts of nutrition in Phoebe bournei and Crypotomeria fortunei forest were 467 819.64 g/hm2 and 20 537.87 g/hm2 more than that in Cunninghamia lanceolata forest. The annual return amount of macroelement in Phoebe bournei was 1.67 and 1.74 times of that in Crypotomeria fortunei and Cunninghamia lanceolata forest. The annual releasing amount of macroelements among the three forest appeared Ca>N>K>Mg>P. Microelements in all litters enriched except in Phoebe bournei leaves. The enrichment amount of microelements was Crypotomeria fortunei forest>Cunninghamia lanceolata forest. Al in leaf and branch litters enriched, and presented Crypotomeria fortunei forest>Cunninghamia lanceolata forest> Phoebe bournei forest.(9)The change degrees of macroelement contents of each layer in Phoebe bournei forest was the smallest, but that of microelements contents was in the contrary. The storage sequence in Cunninghamia lanceolata and Cryptomeria fortunei forests was Al>Fe>K>C>Mg>Ca>N >P>Mn>Zn>Cu, but Fe>Al>K>C>Ca>Mg>N>Mn>P>Zn>Cu.in Phoebe bournei forest. The total C storage was Cryptomeria fortunei forest>Phoebe bournei forest> Cunninghamia lanceolata forests. Compared with Cunninghamia lanceolata, the C storage of Cryptomeria fortunei and Phoebe bournei forest were increased by 33 967.55 kg/hm2,27 181.42 kg/hm. The total Al storage was Phoebe bournei forest>Cryptomeria fortunei forest> Cunninghamia lanceolata forest. Al storage of Phoebe bournei and Cryptomeria fortunei forests increased 157 465.07 kg/hm2 and 80 807.86 kg/hm2 respectively than that of Cunninghamia lanceolata forest. Al storages of Cunninghamia lanceolata forest in decreasing order were soil layer> litter layer>tree layer> shrub layer>herb layer, and that of Cryptomeria fortunei and Phoebe bournei were soil layer>litter layer>tree layer>herb layer> shrub layer. Al storage of three forests concentrated in soil layers and decreasing order was Phoebe bournei forest> Cryptomeria fortunei forest>Cunninghamia lanceolata forest, which accounts for 99.79%,99.99%,99.99% of total Al storage respectively. The huge storage of Al was soil, and Al transferred few to plants. The total storage of nutrient in three forests was Phoebe bournei forest> Cryptomeria fortunei forest> Cunninghamia lanceolata forest. Compared with Cunninghamia lanceolata forest, Phoebe bournei and Cryptomeria fortunei forest increased by 483 955.20 kg/hm2,245 339.01 kg/hm2. In Cryptomeria fortunei and Cunninghamia lanceolata forest, the decreasing order of nutrient storage was soil layer>tree layer>litter layer>shrub layer>herb layer, and that in Phoebe bournei forest was soil layer>tree layer> litter layer> herb layer>shrub layer. In the three forests, the storage of nutrient in soil was higher than other layers.Therefore, soil was the huge nutrient storage.(10) The storage of nutrient in tree layer in Cunninghamia lanceolata forest was N> Ca> K> Fe> Mg> P> Mn> Zn> Cu, that in Cryptomeria fortunei forest was N> Ca> K> P> Mg> Mn> Fe> Zn> Cu, and N>Ca>K>P>Mg>Mn>Fe>Zn>Cu in Phoebe bournei forest. Nutrient enriching laws in three forest was different, but all had strong enriching faction for N, Ca and K elements.(11) The accumulation rates of C, Al and nutrient in tree layers were Phoebe bournei forest> Cryptomeria fortunei forest> Cunninghamia lanceolata forest. The total annual return amounts of nutrition and C were Cryptomeria fortunei forest> Phoebe bournei forest> Cunninghamia lanceolata forest. Compared with Cunninghamia lanceolata forest, C return amounts of Phoebe bournei and Cryptomeria fortunei forest increased byl 187.97 kg/(hm2·a) and 868.64 kg/(hm·a). The total return amount of Al was Cryptomeria fortunei forest> Cunninghamia lanceolata forest> Phoebe bournei forest. The total absorbed amounts of nutrient in Cunninghamia lanceolata and Phoebe bournei forest were 1.46 and 1.43 times of that in Cunninghamia lanceolata forest. The total cycle coefficient of nutrient of the three plantation ecosystems were Cryptomeria fortunei forest> Cunninghamia lanceolata forest> Phoebe bournei forest, and the nutrient cycling intension of Cryptomeria fortunei forest was the strongest, the smallest was Phoebe bournei forest.(12) The total coefficient of return/absorb of C was Cunninghamia lanceolata forest> Cryptomeria fortunei forest> Phoebe bournei forest, and the differences between Cunninghamia lanceolata forest and Cryptomeria fortunei forest was not obvious, meaning that phoebe bournei forest was most difficult to get the C balance between return and absorb. The total cycle coefficient Al was Cryptomeria fortunei forest> Cunninghamia lanceolata forest> Phoebe bournei forest. it was easiest for Cryptomeria fortunei forest to get Al balance between return and absorb, and Phoebe bournei forest was the most difficult one with the smallest cycle strength.(13) The average need of nutrient was 8.99kg/t for Cunninghamia lanceolata forest to produce 1 t dry substances,10.77 kg/t for Cryptomeria fortunei forest, and 13.39 kg/t for the Phoebe bournei forest, which indicated that the using efficiency of nutrient for Cunninghamia lanceolata forest was higher than Cryptomeria fortunei and Phoebe bournei forest. The need of C to produce 1 t dry matter for Phoebe bournei forest was 441.40 kg/t, Cryptomeria fortunei forest 464.40 kg/t, and Cunninghamia lanceolata forest 473.41 kg/t. The using efficiency of C was Phoebe bournei forest> Cryptomeria fortunei forest> Cunninghamia lanceolata forest. To produce It dry matter, the average need of Al for Cunninghamia lanceolata forest was 0.12 kg/t, that of Cryptomeria fortunei forest was 0.11 kg/t, and Phoebe bournei forest needed 0.12 kg/t, showing that the using efficiency of Al for three species was the same.
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