Impact Factor
1.833
5 year Impact Factor
2.299
Editors-in-Chief
Wen-Hao Zhang
Bernhard Schmid
  • Volume 14,Issue 1
    01 February 2021
    (In Progress)
    Research Articles
      Yongjie Liu and Fujiang Hou
      2021, 14 (1): 1-9.
      Abstract ( 17 )   PDF   Save
      Aims

      Seed germinations react to their local growing conditions, but the impacts of soil heterogeneity on seed germinations are not well known.

      Methods

      Effects of three-dimensional soil heterogeneity on seed germinations of grasses species were explored, where two levels of such soil heterogeneity were created via alternatively filling nutrient-poor and nutrient-rich substrate in pot in all directions. Patch sizes of the two heterogeneity levels are around 7.5 and 15 cm, respectively. Fifty seeds of each of the grasses species (Lolium perenne and Elymus nutans) were set either in these heterogeneous soils or in petri dishes with distilled water. Seed germinations of these species were daily recorded.

      Important Findings

      We found that pots with smaller patches had relatively lower germination rate, which is consistent with our expectation that shorter distance between nutrient-rich and nutrient-poor patches in pots with smaller patches allows plants to reduce their germination rates and delay their germination, in order to reduce the negative impacts of the strong variation of soil resources in these pots. Our results also revealed that pots with smaller patches yielded more heterogeneous seed germination, i.e. seed germinations highly diverged among these pots. These findings highlight that the realistic three-dimensional design can improve our understanding of seed germination as driven by soil spatial heterogeneity.

      Kaili Cheng, Zhongmin Hu, Shenggong Li, Qun Guo, Yanbin Hao and Wenping Yuan
      2021, 14 (1): 10-21.
      Abstract ( 9 )   PDF   Save
      Aims

      Prediction of changes in ecosystem gross primary productivity (GPP) in response to climatic variability is a core mission in the field of global change ecology. However, it remains a big challenge for the model community to reproduce the interannual variation (IAV) of GPP in arid ecosystems. Accurate estimates of soil water content (SWC) and GPP sensitivity to SWC are the two most critical aspects for predicting the IAV of GPP in arid ecosystems.

      Methods

      We took a widely used model Biome-BGC as an example, to improve the model performances in a temperate grassland ecosystem. Firstly, we updated the estimation of SWC by modifying modules of evapotranspiration, SWC vertical profile and field capacity. Secondly, we modified the function of controlling water–nitrogen relation, which regulates the GPP–SWC sensitivity.

      Important Findings

      The original Biome-BGC overestimated the SWC and underestimated the IAV of GPP sensitivity, resulting in lower IAV of GPP than the observations, e.g. it largely underestimated the reduction of GPP in drought years. In comparison, the modified model accurately reproduced the observed seasonal and IAVs in SWC, especially in the surface layer. Simulated GPP–SWC sensitivity was also enhanced and became closer to the observations by optimizing parameter controlling nitrogen mineralization. Consequently, the model’s capability of reproducing IAV of GPP has been largely improved by the modifications. Our results demonstrate that SWC in the surface layer and the consequent effects on nitrogen availability should be among the first considerations for accurate modeling IAV of GPP in arid ecosystems.

      Songping Liu, Feng Lin, Xiaolei Su, Qiaoli Ayi, Hangang Niu, Shaohua Shi, Binna Wan, Bo Zeng and Xiaoping Zhang
      2021, 14 (1): 22-32.
      Abstract ( 4 )   PDF   Save
      Aims

      In a large dam-regulated reservoir with regular hydrological pattern and strong flooding gradients across shore elevations, plants inhabiting in different shore elevations have to confront long-lasting flooding of differential intensities every year. Such persistent stress may lead to intraspecific differentiation of flooding tolerance in seeds. Echinochloa crusgalli var. zelayensis is a dominant annual plant in the shores of the Three Gorges Reservoir (TGR), which plays an important role in the shore vegetation. The objective of this study is to check whether intraspecific differentiation of seed flooding tolerance has occurred among E. crusgalli var. zelayensis populations in the TGR shores and whether such differentiation is associated with weak seed dispersal.

      Methods

      We collected seeds of E. crusgalli var. zelayensis from different populations in the TGR shores, and then placed them at four elevations in the shores flooded by reservoir impoundment. Parameters reflecting seed flooding tolerance including post-flooding percentage of intact seeds, seed germinability and seedling emergence rate were investigated for the seeds from different populations and undergoing flooding of different intensities. Floating time of seeds and speed of water level rise during impoundment were examined, and used to quantify dispersal potential of seeds in the shores of the TGR when flooded.

      Important Findings

      Both intact seed percentage and final seedling emergence rate after flooding significantly declined with increasing shore elevations where the seeds were collected, indicating that intraspecific differentiation in seed flooding tolerance has occurred among E. crusgalli var. zelayensis populations in the TGR shores after 7-year operation of the reservoir. The distance of seeds transported by rising water during reservoir impoundment was limited due to short-floating time of the seeds and relatively low speed of water level rise in the reservoir. This would be favourable to the development of intraspecific differentiation in seed flooding tolerance.

  • 2020, Vol. 13 No.6 No.5 No.4 No.3 No.2 No.1
    2019, Vol. 12 No.6 No.5 No.4 No.3 No.2 No.1
    2018, Vol. 11 No.6 No.5 No.4 No.3 No.2 No.1
    Free
    2017, Vol. 10 No.6 No.5 No.4 No.3 No.2 No.1
    Free
    2016, Vol. 9 No.6 No.5 No.4 No.3 No.2 No.1
    2015, Vol. 8 No.6 No.5 No.4 No.3 No.2
    Free
    No.1
    2014, Vol. 7 No.6 No.5 No.4 No.3 No.2
    Free
    No.1
    2013, Vol. 6 No.6 No.5
    Free
    No.4 No.3 No.2 No.1
    2012, Vol. 5 No.4 No.3 No.2 No.1
    Free
    2011, Vol. 4 No.4 No.3 No.1-2
    Free
    2010, Vol. 3 No.4 No.3 No.2 No.1
    Free
    2009, Vol. 2 No.4
    Free
    No.3 No.2 No.1
    2008, Vol. 1 No.4 No.3 No.2 No.1
Highly Cited Articles
Special Issue

Editor’s Choice

The effects of an experimental drought on the ecophysiology and fruiting phenology of a tropical rainforest palm
Nara O. Vogado, Michael J. Liddell, Susan G. W. Laurance , Mason J. Campbell, Alexander W. Cheesman , Jayden E. Engert, Ana C. Palma , Françoise Y. Ishida and Lucas A. Cernusak
Contribution of plant traits to the explanation of temporal variations in carbon and water fluxes in semiarid grassland patches
Mengyu Wang, Nan Lu, Qinglin Li, Weiwei Fang and Bojie Fu
Species-specific responses to drought, salinity and their interactions in Populus euphratica and P. pruinosa seedlings
Lei Yu, Haojie Dong, Zhijun Li, Zhanjiang Han, Helena Korpelainen and Chunyang Li