Pinus Massoniana Forest Research Articles

Landscape and stand structures in a hilly agricultural area in Fenghua City, Zhejiang Province, China: impact of fuelwood collection

Paddy fields surrounded by forests are characteristic of the rural landscapes in East Asia. These characteristic landscapes are maintained by agricultural activities; recently, however, local and regional changes in economic and social systems have resulted in their deterioration. In order to conserve these landscapes, the diversity of land-use systems should be documented, and the human impact on landscape structure should be analyzed. In this study, landscape structure, stand structure, and influence of human activity on the landscape were examined for a hilly agricultural area in Fenghua City, Zhejiang Province, China. Eleven types of landscape elements were recognized that include evergreen broad-leaved forests, evergreen coniferous (Pinus massoniana) forests, tall bamboo (Phyllostachys pubescens) forests, small bamboo (Phyllostachys praecox f. prevernalis) plantations, tea gardens, grasslands, dry arable fields, paddy fields, residential areas, bare ground, and open water. In the study plots, which were established in the main forest types, the species name, cover abundance, and sociability of vascular plants were recorded, and tree height and diameter at breast height were measured. In addition, the amount of fuelwood collected from the forests was determined. There were many component species common to both secondary and natural forests, but the stand structure for these forests was considerably different. Cyclobalanopsis (Quercus) glauca, which had adapted to being frequently cut, was found to be the preferred species for fuelwood.

Estimation of biomass, net primary production and net ecosystem production of China's forests based on the 1999–2003 National Forest Inventory

The National Forest Inventory (NFI) is an important resource for estimating the national carbon (C) balance. Based on the volume, biomass, annual biomass increment and litterfall of different forest types and the 6th NFI in China, the hyperbolic relationships between them were established and net primary production (NPP) and net ecosystem production (NEP) were estimated accordingly. The results showed that the total biomass, NPP and NEP of China's forests were 5.06 Pg C, 0.68 Pg C year−1 and 0.21 Pg C year−1, respectively. The area-weighted mean biomass, NPP and NEP were 35.43 Mg C ha−1, 4.76 Mg C ha−1 year−1 and 1.47 Mg C ha−1 year−1 and varied from 13.36 to 79.89 Mg C ha−1, from 2.13 to 9.15 Mg C ha−1 year−1 and from −0.16 to 5.80 Mg C ha−1 year−1, respectively. The carbon sequestration was composed mainly of Betula and Populus forest, subtropical evergreen broadleaved forest and subtropical mixed evergreen–deciduous broadleaved forest, whereas Pinus massoniana forest and P. tabulaeformis forest were carbon sources. This study provides a method to calculate the biomass, NPP and NEP of forest ecosystems using the NFI, and may be useful for evaluating terrestrial carbon balance at regional and global levels.

Effects of fire disturbance on the soil physical and chemical properties and vegetation of Pinus massoniana forest in south subtropical area

A variety of studies on the impact of fire disturbance on ecosystems has shown that the physical and chemical properties of soil after fire disturbance change notably. Meanwhile, little is known about the effects of different fire intensities on the soil properties and vegetation after fire disturbance, especially in the south subtropical area. In this paper, we analyzed the soil physical and chemical properties, vegetation species and species diversity of fire center, fire edge (which was burned a year ago) and non-burned Pinus massoniana plantation in Gaoyao, Guangdong province, China. The results showed that the soil conductivity, water content, total nitrogen, total potassium, and available potassium content of fire center were significantly higher than those of the non-burned land, and pH was higher than that of fire edge, whereas the available nitrogen, total phosphorus and organic matter content were much lower, which were generally existed in 0–10 cm soil layer and 10–30 cm soil layer. Changes of the soil properties of fire edge were similar with those of fire center, but less significant, and seemed to be more complex. Effects of burning on the vegetation of fire disturbance plots were found to be notable, species number and average height of plants of fire disturbance plots were lower than those of the non-burned plots, a difference of species diversity and uniformity were also shown, and finally, the composition of plant community also changed, e.g., pioneer species such as D. dichotoma, etc., dominated, and drought-resistant plants, heat-resistant plants and positive plants increased after burning.

Inorganic Nitrogen and Available Phosphorus Concentrations in the Soils of Five Forests at Dinghushan, China*

The vertical distribution of inorganic N and available P was studied in the soils of five forests,that is,Pinus massoniana forest(PF),coniferous and broad-leaved mixed forest(MF),monsoon evergreen broad-leaved forest(BF),ravine rain forest(RF)and mountainous evergreen broad-leaved forest(MMF)at Dinghushan in Guangdong,China.The concentrations of inorganic N and available P in four soil layers(0～10cm,10～20cm,20～40cm and 40～60cm)were investigated.The concentrations varied among the different forests,and decreased with the depth of soil,while the ratios of inorganic N to available P increased.In the process of forest succession(PF→MF→BF),the concentrations of inorganic N increased in the four soil layers,while available P accumulated only in the upper two layers(0～10cm and 10～20cm).Furthermore,the percentage of NH4+-N in inorganic N ranked as PFMFBF.The concentrations of inorganic N and available P in soil were not affected by altitude variation among RF,BF and MMF distributed along altitudinal gradient.But,the percentage of NH4+-N in inorganic N was found approximately in the order:BFRFMMF.In addition,there were no signif icant differences in the ratios of inorganic N to available P in all soil layers among the five forests which showed the stages of forest succession or altitude variation.Fig 6,Tab 1,Ref 40

Hydrological characteristics of litter in different forest succession stages at Liuxihe Watershed, southern China

The hydrological characteristics of litter in four different forest succession stages, i.e., a Pinus massoniana forest, a mixed conifer and broad-leaved forest with conifer being the dominant species, a mixed conifer and broad-leaved forest with deciduous trees as dominant species, and an evergreen broad-leaved forest, have been studied by means of substituting space for time. The results show that while a community is developing to a zonal climax, the amount of litter becomes larger and its decomposition intensity becomes stronger; there is a positive relation between its water-holding capacity and velocity and its community maturity for the half-decomposed litter layer.

Impact of invasion of pine wood nematode on the growth of dominant shrub Pleioblastus amarus in Pinus massoniana communities

When pine trees are invaded by pine wilt diseases, the severely infected pine trees will die and fall down, or they will be removed when found to be damaged by the disease. It gives rise to the invasion of other species in these empty niches originally occupied by pine trees, i.e., competing surrounding trees or understory shrubs will invade the empty niches during the following years. As a result, the spatial distribution and pattern of the main tree species in a pine forest will change, and a niche variety in the main population will occur. In the end, the direction of the succession and restoration of the pine forest ecosystem will be affected. In our study, a Pinus massoniana forest with the dominant shrub, Pleioblastus amarus, was invaded by pine wood nematode and was clear cut. Selecting this community as our research object, we studied the effect of the invasion of the pine wood nematode on the growth of the dominant shrub, P. amarus, in this Pinus massoniana forest. Our results show that, after the attacked pine trees were removed, the niche was occupied by Pleioblastus amarus and other shrubs, which benefited the growth of P. amarus to its climax. Growth of P. amarus at the climax stage was greater compared with the unhealthy pine forest and the control group.

Differences in arthropod communities between island and inland Masson pine forests infested by pine wilt disease in Zhejiang Province

The invasion of Bursaphelenchus xylophilus (pine wood nematode, PWN) carried by Monochamus alternatus predominately attacks Masson pine (Pinus massoniana) forests and causes great economic losses in China. In this study, we assessed whether the effect of the invasion of PWN is different between island and inland forests. Arthropods were sampled in Fuyang (inland) and Zhoushan (island) counties in Zhejiang Province with sweep netting and light traps at four plots. During two field periods (May to June 2004 and September to October 2005) a total of 21,916 insects, representing 384 species belonging to 99 families and 15 orders, were collected in the sample plots from the island, whereas, from the inland forest a total of 29,262 insects, representing 308 species belonging to 96 families and 13 orders, were found. A hierarchical cluster analysis (HCA) and one-way ANOVA, based on the composition of different arthropod guilds, were performed. The results showed that there was no significant difference in the composition of arthropod communities at the family level between inland and island. But these two habitats had a significant effect on the composition of species, individuals, sub-communities and energy class levels. Statistically, the composition of the two orders, Lepidoptera and Diptera, in the two habitats were significantly different.

Effect of N and P addition on soil organic C potential mineralization in forest soils in South China

Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N deposition promotes soil C storage through decreasing mineralization; (2) if the soil available P is a limitation to organic carbon mineralization. Soils (0-10 cm) was sampled from monsoon evergreen broad-leaved forest (MEBF), coniferous and broad-leaved mixed forest (CBMF), and Pinus massoniana forest (PMF) in Dinghushan Biosphere Reserve (located in Guangdong Province, China). The soils were incubated at 25 degrees C for 45 weeks, with addition of N (NH4NO3 solution) or P (KH2PO4 solution). CO2-C emission and the inorganic N (NH4(+)-N and NO3(-)-N) of the soils were determined during the incubation. The results showed that CO2-C emission decreased with the N addition. The addition of P led to a short-term sharp increase in CO2 emission after P application, and the responses of CO2-C evolution to P addition in the later period of incubation related to forest types. Strong P inhibition to CO2 emission occurred in both PMF and CBMF soils in the later incubation. The two-pool kinetic model was fitted well to the data for C turnover in this experiment. The model analysis demonstrated that the addition of N and P changed the distribution of soil organic C between the labile and recalcitrant pool, as well as their mineralization rates. In our experiment, soil pH can not completely explain the negative effect of N addition on CO2-C emission. The changes of soil inorganic N during incubation seemed to support the hypothesis that the polymerization of added nitrogen with soil organic compound by abiotic reactions during incubation made the added nitrogen retard the soil organic carbon mineralization. We conclude that atmospheric N deposition contributes to soil C accretion in the three subtropical forest ecosystems, however, the shortage of soil available P in CBMF and PMF may also retard soil organic C mineralization.

Water-holding characteristics of litter in different forests at the Lianxiahe watershed

We surveyed the forest litter amount at the Lianxiahe watershed in the Three Gorges Reservoir Area and analyzed some hydrological characteristics such as the maximum water-holding capacity and water absorption rate of litter in six types of forests, i.e. the Cupressus funebris forest, the coniferous mixed forest, the coniferous and broad-leaved mixed forest, the broad-leaved forest, the Pinus massoniana forest, the bush forest. Results showed that the litter amount follows the order of the coniferous and broad-leaved mixed forest > the pure C. funebris forest, the P. massoniana forest > the coniferous mixed forest > the broad-leaved forest > the bush forest. The maximal water holding capacity of the undecomposed litter is in the order of the C. funebris forest > the coniferous mixed forest > the bush forest > the coniferous and broad-leaved mixed forest > the broad-leaved forest > the P. massoniana forest. The maximal water-holding capacity of the half-decomposed litter is the P. massoniana forest > the coniferous and broad-leaved mixed forest > the C. funebris forest > the coniferous mixed forest > the broad-leaved forest > the bush forest. In this watershed, the water holding capacity of the litter in the C. funebris forest is the highest, followed by the coniferous mixed forest, coniferous and broad-leaved mixed forest, P. massoniana forest, broad-leaved forest and bush forest. When the soil is covered only by litter, both the maximal rainfall amount and intensity in different forest stands are different if there is no water infiltration and runoff from the ground surface.

Belowground carbon balance and carbon accumulation rate in the successional series of monsoon evergreen broad-leaved forest

The balance, accumulation rate and temporal dynamics of belowground carbon in the successional series of monsoon evergreen broadleaved forest are obtained in this paper, based on long-term observations to the soil organic matter, input and standing biomass of litter and coarse woody debris, and dissolved organic carbon carried in the hydrological process of subtropical climax forest ecosystem—monsoon evergreen broad-leaved forest, and its two successional forests of natural restoration—coniferous and broad-leaved mixed forest and Pinus massoniana forest, as well as data of root biomass obtained once every five years and respiration measurement of soil, litter and coarse woody debris respiration for 1 year. The major results include: the belowground carbon pools of monsoon evergreen broad-leaved forest, coniferous and broad-leaved mixed forest, and Pinus massoniana forest are 23191 ± 2538 g·m -2 , 16889 ± 1936 g·m -2 and 12680 ± 1854 g·m -2 , respectively, in 2002. Mean annual carbon accumulation rates of the three forest types during the 24a from 1978 to 2002 are 383 ± 97 g·m -2 ·a -1 , 193 ± 85 g·m -2 ·a -1 and 213 ± 86 g·m -2 ·a -1 , respectively. The belowground carbon pools in the three forest types keep increasing during the observation period, suggesting that belowground carbon pools are carbon sinks to the atmosphere. There are seasonal variations, namely, they are strong carbon sources from April to June, weak carbon sources from July to September; while they are strong carbon sinks from October to November, weak carbon sinks from December to March.

Effects of ecological protection and development on landscape pattern in the Thousand-Island Lake region, Zhejiang Province

Actions of ecological protection and development shape the pattern of a landscape, which in turn affects ecological processes in the landscape. Changes of the fragmented Thousand-Island Lake landscape, formed by the construction of a large dam in 1959, provide an outstanding example. We analyzed the changes in land use and land cover pattern in this region for a period of 39 years (1964-2003) using landscape metrics and 3S technology. Our results showed that the total number of patches and the degree of fragmentation basically remained the same, whereas the patch number, patch area, and dominance of each patch type changed significantly. The most dominant patch type changed from treeless barrens (47.44% of the terrestrial land) in 1964 to the Pinus massoniana forest (52.81% of the terrestrial land) in 2003. We also found that the value of landscape diversity decreased slightly. It is important to note that landscape diversity, a synoptic measure of the richness and evenness of all land use and land cover types, is not always positively related to landscape functioning. The slight decrease in landscape diversity was a result of the dynamics of all existing patches in the study region. Our results suggest that the forest vegetation on the area has improved in terms of coverage since 1964 (i.e., 5 years after the dam construction). These changes may be attributed to the many measures of ecological protection in this region which allowed natural succession to take its course. The improved landscape pattern enhanced ecological functioning of the island ecosystems, including restoration of habitats, increased biodiversity, and reduction in soil erosion. While the forest vegetation has been recovering, the increasing dominance by the structurally simple Pinus massoniana forest in this region should be considered in future efforts of biodiversity conservation, ecological planning, and sustainable development.

Chemical composition of precipitation in a forest area of Chongqing, Southwest China

Experiments were carried.out in Chongging-a city seriously damaged by acid precipitation in southwest China — to explore chemical compositions of open bulk precipitation, throughfall and stemflow in a Masson pine (Pinus massoniana) forest. The results showed that annual mean pH values of and annual ion depositions in the three types of rain water were 4.47 and 50.6 g m−2, 3.82 and 69.7 g m−2, and 2.92 and 0.215 g m−2 respectively. pH values demonstrated an obvious seasonal variation; they were lower in winter than in the rest of the year. Ca2+ and NH inf4 sup+ together made up more than 80% of the total cation, while SO in4 sup2− alone contributed over 90% to the total anion. This high level of SO in4 sup2− in rain water in Chongqing, which outran those found in other cities in China, was closely related to the combustion of locally produced coal that contains 3 to 5% sulphur. Thus, acid precipitation in Chongqing is of a typical sulphuric-acid type.