Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation
Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation
Guan M.,Taizhou University |
Guan M.,Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation |
Jin Z.-X.,Taizhou University |
Jin Z.-X.,Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation |
And 9 more authors.
Chinese Journal of Applied Ecology | Year: 2014
To understand the mechanisms driving community succession in the secondary forest surrounding Qiandao Lake, Zhejiang, China, we investigated seasonal dynamics of the diurnal variations of net photosynthetic rates, their responses to both light and CO2, and chlorophyll fluorescence parameters of four dominant plant species, i. e., Pinus massoniana, Castanopsis sclerophylla, Lithocarpus glaber and Cyclobalanopsis glauca in three natural light habitats, i. e., gap, edge and understory. In the three different light regimes, the daily mean values of the net photosynthetic rate (Pn) of P. massoniana and C. sclerophylla were significantly higher in summer than in the other seasons, while Pn of L. glaber and C. glauca was significantly higher in autumn than in the other seasons. In the forest gap and edge habitats, the annual mean values of the maximum net photosynthetic rate(Amax), the light saturation point(LSP), light compensation point(LCP) and dark respiration rate(Rd) of P. massoniana were the highest, followed by C. sclerophylla, and those of L. glaber and C. glauca were the lowest. In the understory habitat, the annual mean values of Amax and the apparent quantum yield(AQY) of C. glauca were the highest, followed by L. glaber and C. sclerophylla, and those of P. massoniana were the lowest. The annual mean values of the maximum rate of carboxylation(Vc max), maximum rate of electron transport(Jmax) and triose phosphate use rate(TPU) of P. massoniana were significantly higher than those of the other three plant species in the three different light regimes. During the four seasons, the photochemical maximum efficiency of PSII(Fv/Fm) of P. massoniana and C. sclerophylla in the forest gap habitat was significantly higher, while those of L. glaber and C. glauca in the understory habitat were significantly higher than in the other light regimes. The maximum values of Fv/Fm of P. massoniana and C. sclerophylla were the highest in summer, and those of L. glaber and C. glauca were the highest in autumn. It suggested that P. massoniana and C. sclerophylla were more suitable for habitats with high light intensities such as forest gaps, and L. glaber and C. glauca were more suitable for habitats with low light intensities such as the understory. During ecological succession, P. massoniana and C. sclerophylla would withdraw from the community with the increasing canopy density, and L. glaber and C. glauca would be the dominant species in the climax community.
Guo S.M.,Shanxi Normal University |
Guo S.M.,Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation |
Guo S.M.,Taizhou University |
Li J.M.,Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation |
And 4 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2014
The uncontrolled range expansion of invasive plant species has become a worldwide problem in this century. Finding suitable biological control measures for these invasive species has become a focus for many biologists. Using biological control species that are not native to the invaded community can generate further problems in the community. Thus, in recent years, scientists have started to look for enemies that are (1) able to inhibit growth in an invasive species, and (2) native to the invaded region. Parasitic plants are one example of such novel native enemies. Several studies provide support for the use of native parasitic plants as potential biological control agents for invasive plants. However, the exact response of invasive plants to the parasitic plants is still poorly known. In this study, the relationship between a common invasive plant Alternanthera philoxeroides (Amaranthaceae) and its native parasitic plant Cuscuta australis (Convolvulaceae) was investigated. A. philoxeroides is a notorious invasive weed that originates from South America. It is widely distributed in China and has had a marked negative impact on local biodiversity and the economy of China. C. australis, a native holoparasitic plant in China, has been found to naturally parasitize invasive A. philoxeroides in the field. The growth of the parasite depends on assimilation of the host’s nutrients and water. A field survey was conducted to investigate the trade-off between growth and defense in A. philoxeroides in response to parasitization by C. australis. Biomass of A. philoxeroides and the secondary metabolite composition in the stems with or without C. australis were measured. Results showed the following: (1) Root mass, stem mass, leaf mass, total biomass and leaf number of A. philoxeroides were significantly reduced in plants parasitized by C. australis, but the number of stem nodes significantly increased. Clonal reproduction of A. philoxeroides mainly relies on the stem nodes; thus, the results indicate a significant inhibition of growth and an increased investment in clonal reproductive ability. (2) Parasitization by C. australis significantly increased the secondary metabolite contents in stems of A. philoxeroides, including lignin, total phenols, tannins and tri-terpenoid saponin. These four types of secondary metabolite play important roles in the plant when under stress. The increase in secondary metabolites indicates an enhanced defense capability in the host. (3) The total biomass of A. philoxeroides parasitized by C. australis was significantly reduced, while the relative percentage content of secondary metabolites significantly increased. Moreover, a significant negative correlation was found between total biomass and secondary metabolite content in stems of A. philoxeroides parasitized by C. australis. Overall, this study suggests that in response to parasitism by C. australis, A. philoxeroides alters its balance in investment between growth and defense, with less investment in growth and more on clonal reproduction and defense. Such a trade-off strategy between growth and defense may help invasive plants mitigate the negative effects of new native enemies in the invaded community. Nonetheless, native parasitic plants do provide a novel enemy for invasive plant species and may provide a less risky but effective way to control invasive plants. © 2014, Science Press. All rights reserved.
Yang B.-F.,Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation |
Yang B.-F.,Taizhou University |
Du L.-S.,Beijing Forestry University |
Li J.-M.,Zhejiang Province Key Laboratory of Plant Evolutionary Ecology and Conservation |
Li J.-M.,Taizhou University
Chinese Journal of Applied Ecology | Year: 2015
In order to find out how parasitic Cuscuta australis influences the growth and reproduction of Solidago canadensis, the effects of the parasitism of C. australis on the morphological, growth and reproductive traits of S. canadensis were examined and the relationships between the biomass and the contents of the secondary metabolites were analyzed. The results showed that the parasitism significantly reduced the plant height, basal diameter, root length, root diameter, root biomass, stem biomass, leaf biomass, total biomass, number of inflorescences branches, axis length of inflorescence, and number of inflorescence. In particular, plant height, number of inflorescence and the stem biomass of parasitized S. canadensis were only 1/2, 1/5 and 1/8 of non-parasitized plants, respectively. There was no significant difference of plant height, root length, stem biomass and total biomass between plants parasitized with high and low intensities. But the basal diameter, root volume, leaf biomass, root biomass, the number of inflorescences branches, axis length of inflorescence and number of inflorescence of S. canadensis parasitized with high intensity were significantly lower than those of plants parasitized with low intensity. The parasitism of C. australis significantly increased the tannins content in the root and the flavonoids content in the stem of S. canadensis. The biomass of S. canadensis was significantly negatively correlated with the tannin content in the root and the flavonoids content in the stem. These results indicated that the parasitism of C. australis could inhibit the growth of S. canadensis by changing the resources allocation patterns as well as reducing the resources obtained by S. canadensis. © 2015, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.