Wang H.-B.,Institute of Biodiversity Science |
Qin J.,Shanghai Botanical Garden |
Hu Y.-H.,Chenshan Botanical Garden |
Dong L.,Beijing Forestry University |
Chen J.-K.,Institute of Biodiversity Science
Applied Mechanics and Materials | Year: 2012
The Humble Administrator's Garden is not only the topmost classical private garden south of the Yangtze River in China, but a member of the World Culture Heritage List. Its rich plant landscape patterns around housings have valuable effects on today's building environment. This study tried to explore the spatial preferences of plant landscape dynamics of the garden. The 13 sample plots, each of which centered about a building and 12m outward radiation, were investigated in February and August 2010. We recorded totally 53 tree species and 325 individuals. Tree height, defoliation, direction (relative to building) and spacing (distance from building) were divided into levels of 6, 2, 8 and 4 respectively. Each level was encoded in order. Thus a tree had a four-digit code including the four factors. There were 4 evergreen gymnosperms which had only a little effect on building daylighting. Both the defoliation ratio of 0.69 and dominant species of most deciduous species showed primary deciduous trees were valuable to realize the balance of daylighting, ventilation and seasonal beauty. The result of small evergreen trees and large deciduous trees is valuable for both sunshine and green in winter as well as shading in summer. Most small trees on the west can be barrier against the hot sun on summer afternoon. Most large trees on the south are beneficial to southern shading and ventilation. Finally, the open space before window is necessary for daylighting and ventilation. © (2012) Trans Tech Publications.
Choi C.,Institute of Biodiversity Science |
Gan X.,Alabama A&M University |
Hua N.,Institute of Biodiversity Science |
Wang Y.,Alabama A&M University |
And 2 more authors.
Wetlands | Year: 2014
Natural coastal wetlands are important habitats for shorebirds while flooded agricultural croplands, may also be useful habitats. Shorebirds in East Asia utilize an often highly developed coastal landscape, which may be dissected by seawalls with intertidal flats on the seaward side, and aquaculture ponds and agricultural croplands on the landward side. Little is known about the value of aquaculture ponds to shorebirds. We investigated the habitat use, preference and home range of wintering Dunlin (Calidris alpina) in Chongming Dongtan, east China, through radio tracking and field observations in 2006-2007. Our results indicated that Dunlins preferred tidal flats, avoided agricultural croplands, and used aquaculture ponds in proportion to their availability. The probability of Dunlin usage of aquacultural ponds decreased with increasing size of unflooded area in the aquaculture ponds. Dunlins foraging in aquaculture ponds had lower feeding success rate than those in tidal flats. Thus, tidal flats may provide important foraging habitat for wintering Dunlins, while aquaculture ponds may provide alternative roosting and supplemental foraging habitat. Conserving the natural wetlands on tidal flats is vital for shorebird conservation in East Asia but at the same time, the aquaculture ponds also could play an important role if managed properly © Society of Wetland Scientists 2013.
Haiqiang G.,Institute of Biodiversity Science |
Haiqiang G.,University of Toledo |
Bin Z.,Institute of Biodiversity Science |
Jiquan C.,Institute of Biodiversity Science |
And 3 more authors.
Chinese Geographical Science | Year: 2010
The energy budget and regulating factors were investigated over an estuarine wetland during one year of continuous measurement in 2006. The results show that the seasonal changes of the energy fluxes and Bowen ratio (β) were greatly affected by incoming shortwave radiation and canopy growth. During the non-growing season and early-growing season, sensible heat (H) dominated the energy flux, and β could reach a maximum of 2.5, while during most of the growing season, latent heat dominated the energy flux and β fluctuated from 0.4 to 1.0. The energy budget ratio in growing season was about 0.76, and the value would be higher if heat exchange during tidal flooding was included. During tidal flooding days, β was slightly higher than that at exposure days in most cases. Vegetation cover seems exert little effect on energy partitioning except in March when the standing dead grass intercepted the incoming radiation that might reach the soil surface and reduce the turbulence between soil and atmosphere, thus suppressing the evaporation from the soil though the soil mositure was high at that time. © Science Press and Northeast Institute of Geography and Agricultural Ecology.
Yan Y.-E.,Institute of Biodiversity Science |
Yan Y.-E.,Chongqing Normal University |
Ouyang Z.-T.,Institute of Biodiversity Science |
Guo H.-Q.,Institute of Biodiversity Science |
And 2 more authors.
Journal of Hydrology | Year: 2010
This study was conducted to develop a novel technique of monitoring tidal floods and their spatiotemporal dynamics using a time series combination of the MODIS vegetation indices (VIs). The vegetation indices, which included the enhanced vegetation index (EVI), land surface water index (LSWI) and the difference in the values of EVI and LSWI (DVEL), were extracted from MODIS datasets with a spatial resolution of 500 m from 2001 to 2006. The technique first employed a wavelet-analysis to reduce the noise component of the time series of VIs, after which the smoothed time profiles were used to identify the spatiotemporal changes in tidal flood effects on estuarine wetland from islands to sea front. We found that combined application of EVI, LSWI and DVEL was suitable for monitoring flood inundation and recording flood dynamics and vegetation succession. Our approach takes advantage of both the flooded soils and canopy characteristics of vegetation during the tidal cycle and vegetation growth phases. The results of this study demonstrate the potential for the use of MODIS data for temporal and spatial detection of tidal flood effects in estuarine wetlands. © 2010 Elsevier B.V. All rights reserved.
Nie M.,Institute of Biodiversity Science |
Xian N.,Institute of Biodiversity Science |
Fu X.,Tongji University |
Chen X.,Fudan University |
Li B.,Institute of Biodiversity Science
Journal of Hazardous Materials | Year: 2010
In order to understand how petroleum-hydrocarbon spillage and plant rhizosphere interact to affect concentrations and distribution of heavy metals, nine metals were analyzed from four different types of sediments (i.e. petroleum-hydrocarbon spilled rhizosphere, pristine rhizosphere, petroleum-hydrocarbon spilled unvegetated, and pristine unvegetated) in the Yellow River Delta, China. Our results showed that petroleum-hydrocarbon spillage together with rhizosphere effects were responsible for the significantly higher levels of metals in these four types of sediments. Compared to unvegetated sediments, rhizosphere sediments were well grouped into petroleum-hydrocarbon spilled and pristine sites on the basis of the concentrations of heavy metals by the correspondence analysis (CA). Furthermore, analysis of the transfer factors indicated that the capacity of rhizosphere sediments to stabilize heavy metals increased with increasing petroleum-hydrocarbon spillage, which might be due to the changes of sediment profiles by plant rhizosphere. Our results suggested that interactive effects of petroleum-hydrocarbon spillage and plant rhizosphere played an important role in determining concentrations and spatial distribution pattern of heavy metals. © 2009 Elsevier B.V. All rights reserved.
Pan X.-Y.,Institute of Biodiversity Science |
Weiner J.,Copenhagen University |
Li B.,Institute of Biodiversity Science
Journal of Systematics and Evolution | Year: 2013
Plant responses to crowding have been investigated extensively in stands of light-demanding species, but shade-tolerant species may react differently. In the present study, we investigated the effect of density on the mortality, size inequality, and biomass allocation of Alternanthera philoxeroides, a shade-tolerant invasive species. Stem fragments of A. philoxeroides were grown at either low or high densities (6 vs. 24 plants per pot) under three light levels (10%, 34%, and 100% full sun). After 8 weeks, survival was 31% lower in pots with a higher initial density. Both high density and low light levels reduced plant size substantially. Mean plant biomass ranged from 0.23 g in high-density and low-light pots to 4.41 g in low-density and high-light pots. There were no strong or significant effects of density or light level on size inequality of survivors. Most of the variation in allocation and morphology in response to light level and crowding were due to plant size and allometric growth, with little evidence of true plasticity. There was a small but significant increase in shoot allocation, in the direction predicted by optimal allocation theory, at low light levels. Our results show that intense competition need not be size asymmetric, and suggest that tolerance to low light levels involves a reduction in phenotypic plasticity. Responses of the invasive A. philoxeroides to crowding may be an example of an invasive plant's success in establishing dense stands of closely related individuals that are shade tolerant, cooperative, and follow a relatively fixed allometric trajectory with low plasticity. © 2013 Institute of Botany, Chinese Academy of Sciences.
Xie X.,Institute of Biodiversity Science |
Zhang M.-Q.,Institute of Biodiversity Science |
Zhao B.,Institute of Biodiversity Science |
Guo H.-Q.,Institute of Biodiversity Science
Biogeosciences | Year: 2014
Variations in temperature are widely invoked to explain fluctuations in ecosystem respiration (ER), but hydrological conditions also influence ER. Many researchers have observed that aperiodic variations in hydrological conditions affect ER and the associated temperature sensitivity. However, little is known about how periodic hydrological dynamics affect ER and its relationship with temperature on different timescales. In the present study, data from two coastal wetland sites were used to compare the variations in thermal and tidal influences on ER at three timescales (monthly, seasonal, and semiannual), and we found that (1) the influences of tides and temperature on ER varied with time. Especially in summer, the ER exhibited periodic dynamics regulated by tides; (2) in the temporal domain, temperature was dominant at the semiannual and seasonal scales, while the tidal effect was dominant at the monthly scale. In the spatial domain, the relative importance of temperature was greater at higher elevation sites, while tides exerted more influence at lower elevation sites; (3) the monthly model with tidal effect performed best, while regression models at semiannual and seasonal scales generated systematic errors in ER. These results demonstrate that, for coastal wetlands, the application of parameters from regression models based on long-term (seasonal or semiannual) data should be avoided in gap filling, and the effects of tides and elevation should be considered in estimating the carbon budget. © 2014 Author(s).