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Soils are commonly spatially heterogeneous and earthworms are widely distributed in terrestrial ecosystems. While both soil heterogeneity and earthworms can influence the performance of plants, whether they can interact to affect the growth of bamboo species has not been examined. In a greenhouse experiment, we planted two dwarf bamboo species, Sasa argenteosriata and Sasaella glabra, separately in a heterogeneous soil consisting of two different types of soil patches and in a homogeneous soil in which the two types of soil patches were evenly mixed. These soils were added with or without earthworms. Both S. argenteosriata and S. glabra grew more in the heterogeneous soil than in the homogeneous soil and in the soil with earthworms than in the soil without earthworms. Soil heterogeneity and earthworms did not interact to influence the performance of either bamboo species. Independent of the presence of earthworms, both bamboo species grew equally well in the two types of soil patches within the heterogeneous soil, indicating that the foraging behavior of bamboos is weak; this is likely because resource translocation between interconnected ramets located in different soil patches homogenized plant responses to different resource levels. These results indicate that a heterogeneous supply of nutrients may aid in the growth of bamboo species, and these actions should be integrated into the sustainable management of bamboo forests.

Global climate change has great effects on ecosystems via changes in air and soil temperature. While the effects of temperature have been extensively studied, relatively few studies have truly separated the impact of soil temperature from that of air temperature. Furthermore, little is known about how removal of older ramets may affect the performance of their interconnected younger ramets of bamboos. By maintaining air temperature constantly (at 17 °C) in growth chambers and manipulating soil temperature (2, 7, 12, 17 and 22 °C) using thermostatic water bath systems, we tested the effects of soil temperature and removal of the older ramets on survival, growth and physiology of its interconnected young ramet of a bamboo Indocalamus decorus. Soil temperature significantly affected the survival of the young ramet of I. decorus and also the growth and photosynthetic rate of the surviving young ramet when the shoots of its connected older ramets were not removed. Removing shoots of the older ramets greatly enhanced the survival of the young ramet at the two highest soil temperatures (17 and 22 °C) and the growth of the surviving ramet at 7 and 12 °C. We conclude that shoot removal of older ramets can interact with soil temperature to affect survival and growth of young ramets of the bamboo, and that resource sharing (translocation of photosynthates) from older ramets to young ramets of the bamboo is rather limited. Instead, newly emerged, interconnected ramets of bamboos may compete fiercely for resources stored in rhizomes. These results suggest that bamboo forest management should consider the balance between resource sharing and competition for resources stored in rhizomes under ongoing global climate change.

Mineral nutrients play a critical role in maintaining plant growth, but are vulnerable to climate change, such as elevated atmospheric carbon dioxide (CO2) concentrations. Previous studies reported that impact of elevated CO2 concentrations on plant growth vary among plant species, which may affect differential mineral nutrient cycling among plant species. However, little is known about how increasing CO2 concentrations affect mineral nutrient uptake and allocation in bamboo species. Using open top chambers (OTCs), we investigated the effects of elevated CO2 concentrations on three key mineral nutrients (iron (Fe), calcium (Ca), and magnesium (Mg)) in two mature bamboo species (Phyllostachys edulis and Oligostachyum lubricum). Results showed increased leaf and root biomass under elevated CO2 concentrations (P. edulis: 30.24% and 10.94%; O. lubricum: 24.47% and 13.84%, respectively). Conversely, elevated CO2 concentrations had negligible effects on the biomass of other bamboo organs (e.g., branches and culms). To a certain extent, elevated CO2 concentrations also caused nutrient variation among the various organs of these two species. For Ph. edulis, elevated CO2 concentrations increased mineral content (Fe, Ca, and Mg) in and allocation to leaves while it decreased Fe and Mg allocation to roots. By contrast, elevated CO2 concentrations only increased mineral content in and allocation to O. lubricum leaves and decreased Mg to its roots. Results confirmed that elevated CO2 concentrations resulted in differential mineral nutrient uptake and allocation response between these two species. Understanding such differences is critical to the sustainable nutrient management of bamboo ecosystems under increasing CO2 concentrations.

Awareness of local-scale variation in leaf traits for a single species and the relationships between these traits and their dependence on altitude might be essential for extrapolating ecophysiological processes from the leaf to the ecosystem level. While altitudinal patterns of leaf traits have been extensively studied in a number of species, little is known about such patterns in bamboos. We analyzed leaf functional traits and leaf allometric relationships of Pleioblastus amarus at three different altitudes (200, 400, and 800 m). With increasing altitude, most functional traits, including leaf length, width, perimeter, area, dry weight, and water content, decreased significantly, while the leaf length:width ratio exhibited a marked increase, resulting in a tendency toward narrow leaves. Specific leaf area first increased, and then decreased, while the change in leaf dry matter content showed the opposite trend. Leaf area was positively correlated with leaf length, leaf width and leaf perimeter, but negatively correlated with the leaf length:width ratio. With increasing altitude, the slopes of these relationships for leaf area first increased, and then decreased. Leaf biomass was positively correlated with leaf length, width, perimeter, and area, with the slopes of the relationships being the same at all altitudes. Thus, the leaves of this bamboo species at middle altitude have the highest specific leaf area and lowest leaf dry matter content. Our findings suggest that this bamboo species has a big potential of growth and morphological plasticity.

Rising CO2 and O3 concentrations significantly affect plant growth and can alter nutrient cycles. However, the effects of elevated CO2 and O3 concentrations on the nutrient dynamics of bamboo species are not well understood. In this study, using open top chambers (OTCs), we examined the effects of elevated CO2 and O3 concentrations on leaf biomass and nutrient (N, P, and K) dynamics in two bamboo species, Phyllostachys edulis (Carriere) J.Houz. and Oligostachyum lubricum (wen) King f. Elevated O3 significantly decreased leaf biomass and nutrient uptake of both bamboo species, with the exception of no observed change in K uptake by O. lubricum. Elevated CO2 increased leaf biomass, N and K uptake of both bamboo species. Elevated CO2 and O3 simultaneously had no significant influence on leaf biomass of either species but decreased P and N uptake in P. edulis and O. lubricum, respectively, and increased K uptake in O. lubricum. The results indicate that elevated CO2 alleviated the damage caused by elevated O3 in the two bamboo species by altering the uptake of certain nutrients, which further highlights the potential interactive effects between the two gases on nutrient uptake. In addition, we found differential responses of nutrient dynamics in the two bamboo species to the two elevated gases, alone or in combination. These findings will facilitate the development of effective nutrient management strategies for sustainable management of P. edulis and O. lubricum under global change scenarios.

Water and nitrogen are two of the most important factors for plant growth and development. However, little is known about effects of N on water translocation between connected bamboo ramets. We performed experiment connected Indocalamus decorus ramets in adjacent pots with different soil water contents and three N levels. We determined antioxidase activities, concentration of osmotic adjustment products, O2·−, MDA and photosynthetic pigments, and electrolyte leakage rate in paired unit. When N supply to supporting ramets increased, their electrolyte leakage rates and contents of O2·− and MDA significantly increased, while antioxidase activities and contents of osmotic adjustment products and photosynthetic pigments in connected dependent ramets increased markedly as their electrolyte leakage rates and contents of O2·− and MDA decreased greatly. When N addition to dependent ramets increased, antioxidant enzyme activity and contents of osmotic adjustment products and photosynthetic pigments decreased in both ramets, but electrolyte leakage rates and O2·− and MDA contents increased significantly. Therefore, N addition to either supporting or dependent ramets can improve water integration among I. decorus ramets. N addition to supporting ramets promotes water translocation and alleviates water stress of dependent ramets, but N addition to dependent ramets exacerbates drought stress damage to dependent ramets.

Niche characteristics of nineteen main associated tree populations in moso bamboo mixed forests in Luoboyan Natural Reserve were investigated. The results show that associated populations ofSarcandra glabra,Ilex purpureaandEurya japonica, with high important values have great capacity of adapting to environment and also have broader niche breadths.Liquidamba formosanaseldom appear as associated trees and have narrow niche breadth.Castanopsis fargesii,Engelhardia fenzelii,Castanopsis kawakamii,Schima superba,Nyssa aquaticandCarpinus turczaninowiihave close niche breadth and similar distribution range within the community.Ilex purpurea-Castanopsis fargesii,Ilex purpurea-Engelhardia fenzelii,Engelhardia fenzelii-Liquidamba formosana,Castanopsis kawakamii-Dendropanax dentiger,Rhododendron pulchrum-Schima superba,Dendropanax dentiger-Castanopsis lamontiiandCastanopsis lamontii-Carpinus turczaninowiihave high niche overlaps which prove that species having similar or same circumstances demands high niche overlap indexes. Species with broader niches have more chances for niche overlap with other species.Sarcandra glabradistributes widely and has broad niche breadth but low overlap index with other species, which indicates that species with broad niche breadth is not inevitable to have broad niche overlap with other species.

Anthropogenic disturbance measures have complex effects on understory plants. In order to establish a theoretical basis for moso bamboo forest sustainable management, three types of moso bamboo forests with many years not weeding, hilltops weeding and herbicides weeding were choosed. And species names, numbers and coverages of all arbors, shrubs, herbs and vines were recorded in every quadrat. Species composition and α-diversity were analyzed to compare understory vegetation under the three types of moso bamboo forests with consistent stand structure and site conditions. There are four major findings in this study: (1) 74 species belonged to 47 families and 58 generas which are recorded in the three types of moso bamboo forests. Many years not weeding, hilltops weeding and herbicides weeding are respectively 33 families 39 genera 40 species, 33 families 37 genera 41 species and 37 families 43 genera 49 species. (2) Dominant species of arbors and shrubs within hilltops weeding and herbicides weeding moso bamboo forests are less than the ones of many years not weeding moso bamboo forest, whereas dominant species of herbs increased. Meanwhile, co-dominant specie of arbors is Cunninghamia lanceolata, shrubs is Rubus reflexus, and herbs are Melastoma dodecandrum and Dicranopteris dichotoma. (3) Richness of herbicides weeding and hilltops weeding moso bamboo forests is significantly lower than (ppC), Simpson diversity index (D),Shannon-Wiener diversity index (H) and Pielou evenness index (J) among the three types of moso bamboo forests are not significant. Considering understory plant diversity and system structure stability analysis, anthropogenic hilltops weeding measure is suggested to be used for understory vegetation interference.

The research was to approach the growth strategy of rhizome and roots based on the morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged conditions, and provided a theoretical basis for its application for vegetation restoration in wetland and water-level fluctuation belts. The morphological characteristics, physiological and biochemical indexes of annual bamboo rhizome and roots were investigated with an experiment using individually potted P. rivalis which was treated by artificial water-logging for 3, 6, and 12 months. Accordingly the morphological characteristics, biomass allocation, nutrient absorption and balance in rhizome and roots of P. rivalis were analyzed. The results showed that there was no obvious impact of long-term water-logging on the length and diameter of rhizomes, diameter of roots in P. rivalis. The morphological characteristics of rhizome had been less affected generally under water-logging for 3 months. And less rhizomes were submerged, while the growth of roots was inhibited to some extent. Furthermore, with waterlogging time extended, submerged roots and rhizomes grew abundantly, and the roots and rhizomes in soil were promoted. Moreover for ratios of rhizome biomass in soil and water, there were no obvious variations, the same for the root biomass in soil to total biomass. The ratio of root biomass in water to total biomass and the ratio of root biomass in water to root biomass in soil both increased significantly. The results indicated that P. rivalis could adapt to waterlogged conditions gradually through growth regulation and reasonable biomass distribution. However, the activity of rhizome roots in soil decreased and the nutrient absorption was inhibited by long-term water-logging, although it had no effect on stoichiometric ratios of root nutrient in soil. The activity of rhizome root in water increased and the stoichiometric ratios adjusted adaptively to waterlogged conditions, the ratio of N/P increased, while N/K and P/K decreased, which implied that roots in water absorbed oxygen and nutrients could help P. rivalis adapt to long-term waterlogged environment effectively.

BACKGROUND: Xenobiotic organochlorine pesticides (OCPs) are a major environmental problem because of their historic widespread use, pronounced persistence against chemical and biological degradation, and bioaccumulation in the food chain. Pesticide use is prevalent in the production of edible bamboo shoots, which are exported widely from China. To evaluate the quality of Chinese bamboo shoots we determined the residual content of some OCPs in shoot samples. RESULTS: Three types of OCPs—hexachlorocyclohexane (HCH), 1,1,1-trichlor-2,2-bis(p-chlorophenyl)ethane (DDT) and pentachloronitrobenzene (PCNB)—were detected in bamboo shoots from Zhejiang province, China. Detection rates were 100%, 100% and 75% for HCH, DDT and PCNB, respectively. However, the average residue concentration did not exceed the maximum residue limit for pesticides detected in food in China (50 µg kg−1). In terms of residue concentrations of the pesticides, 82.14% of the bamboo shoot samples could be classified as safe. CONCLUSION: While all sampled bamboo shoots contained OCP, most (82.14%) were safe for consumption. Copyright © 2010 Society of Chemical Industry

To understand the physiological adaptive mechanism of Phyllostachys violascens to intensive mulching management, the effect of mulching management (CK, 1, 3 and 6 years) on the concentrations and ratios of non-structural carbohydrates (NSC), nitrogen (N) and phosphorus (P) in bamboo foliage, and their stoichiometry was investigated. The results showed the concentrations of NSC and soluble sugar increased, while the starch content and N/P decreased markedly in bamboo stand with 1-year mulching, compared to CK stand, which suggested the N limitation to bamboo growth was strengthened. Foliar soluble sugar content decreased significantly, while the starch content increased dramatically, and the NSC content by per unit mass of N and P reached the maximum in the bamboo stand with 3-year mulching, compared to all other treatments. Foliar NSC and soluble sugar contents decreased significantly, while foliar starch content and N/P increased dramatically in the stand with 6-year mulching, which suggested the P limitation to bamboo growth was strengthened. Foliar NSC content was positively correlated with N and P concentrations in a short-term mulching management stand (≤ 3 years), while showed negative relationship with N/P. The foliar starch content in the stand with 6-year mulching was negatively correlated with N and P contents, while was positively correlated with N/P. The results indicated that short-term mulching management accelerated the accumulation of soluble sugar and decomposition of starch in foliage, thus the growth and activity of Ph. violascens was enhanced greatly. Long-term mulching management promoted the starch accumulation, which led to the transition from N limitation to P limitation for bamboo growth. In summary, long-term (6 years) mulching management caused the decrease of growth and activity of Ph. violascens dramatically, thus enhancing the bamboo stand degradation. The utilization efficiency of N and P reached the highest in the stand with 3-year mulching, which implied 3-year was the best suitable period for intensive mulching management for maintaining bamboo stand quality.

By using open-top chambers (OTCs) to simulate the scenes of elevated CO2 concentrations [500 micromol x mol(-1) (T1) and 700 micromol x mol(-1) (T2)], and taking ambient atmospheric CO2 concentration as the control (CK), this paper studied the effects of elevated CO2 concentration on the lipid peroxidation and anti-oxidation enzyme system in Indocalamus decorus, Pleioblastus kongosanensis, and Sasa glabra leaves. After 103 days treatment, the O2(-)* and MDA contents, relative electron conduction, and soluble sugar content in the three dwarf ornamental bamboo species leaves in T1 had no obvious change, but the activities of anti-oxidation enzymes (SOD, POD, CAT, and APX) changed to a certain extent. In T2, the MDA content and relative electron conduction had no obvious change, but the O2(-)* and soluble sugar contents and the anti-oxidation enzymes activities changed obviously. The adaptation capacity of the three bamboo species to elevated CO2 concentration was in the order of I. decorusP. kongosanensisS. glabra.

Taking pure Oligostachyum lubricum forest as test object, this paper studied the matured and withered leaves carbon (C), nitrogen (N), and phosphorus (P) stoichiometry and N and P resorption patterns of 1-3 years old stands at the densities of 24600-29800 stem hm-2 (D, ), 37500-42600 stem hm-2 (D2 ), 46500 - 52800 stem hm-2 (D3), and 76500 - 85500 stem hm-2 (D4). With increasing stand density, the matured leaves C, N, and P contents and withered leaves C and P contents had an overall decrease, the withered leaves N content decreased after an initial increase, and the matured leaves C content at density )4 decreased dramatically. The leaf C/N and C/P ratio increased with increasing stand density, whereas the leaf N/P ratio increased first but decreased then. At stand densities D3 and D4, the leaf N and P utilization efficiencies were significantly higher than those at D, and D2. With increasing stand density, the leaf N resorption capacity increased after an initial decrease, while the leaf P resorption capacity increased steadily. At stand densities D,-D3, the matured leaves N/P ratio was 16.24-19.37, suggesting that the P limitation occurred, leaf establishment increased, and population increase and expansion enhanced. At density D4, the matured leaves N/P ratio was 13.42-15.74, implying that the N limitation strengthened, leaf withering and defoliation increased, and population increase inhibited. All the results indicated that O. lubricum could regulate its leaf C, N and P contents and stoichiometry and enhance the leaf N and P utilization efficiency and resorption capacity to adapt to the severe competition of environment resources at high stand density. In our experimental condition, 46500-52800 stem hm-2 could be the appropriate stand density for O. lubricum management.