Effects of plant diversity on biomass production and substrate nitrogen in a subsurface vertical flow constructed wetland

Abstract Most biodiversity experiments have been conducted in grassland ecosystems with nitrogen limitation, while little research has been conducted on relationships between plant biomass production, substrate nitrogen retention and plant diversity in wetlands with continuous nitrogen supply. We conducted a plant diversity experiment in a subsurface vertical flow constructed wetland for treating domestic wastewater in southeastern China. Plant aboveground biomass production ranged from 20 to 3121 g m −2  yr −1 across all plant communities. In general, plant biomass production was positively correlated with species richness ( P  = 0.001) and functional group richness ( P  = 0.001). Substrate nitrate concentration increased significantly with increasing plant species richness ( P  = 0.046), but not with functional group richness ( P  = 0.550). Furthermore, legumes did not affect biomass production ( P  = 0.255), retention of substrate nitrate ( P  = 0.280) and ammonium ( P  = 0.269). Compared to the most productive of the corresponding monocultures, transgressive overyielding of mixed plant communities did not occur in most polycultures. Because greater diversity of plant community led to higher biomass production and substrate nitrogen retention, thus we recommend that plant biodiversity should be incorporated in constructed wetlands to improve wastewater treatment efficiency.

[1]  E. Schulze,et al.  THE ROLE OF PLANT DIVERSITY AND COMPOSITION FOR NITRATE LEACHING IN GRASSLANDS , 2003 .

[2]  J. Roy,et al.  Plant biomass production and soil nitrogen in mixtures and monocultures of old field Mediterranean annuals , 2003 .

[3]  Jie Chang,et al.  Effects of plant diversity on microbial biomass and community metabolic profiles in a full-scale constructed wetland. , 2010 .

[4]  Pengyi Zhang,et al.  Phosphorus removal from agricultural runoff by constructed wetland. , 2009 .

[5]  A. Lüscher,et al.  Does nitrogen nutrition restrict the CO2 response of fertile grassland lacking legumes? , 1997, Oecologia.

[6]  P Kuschk,et al.  Effects of plants and microorganisms in constructed wetlands for wastewater treatment. , 2003, Biotechnology advances.

[7]  D. Tilman,et al.  Species loss and ecosystem functioning : effects of species identity and community composition , 1998 .

[8]  Huub J. Gijzen,et al.  Effect of total ammonia nitrogen concentration and pH on growth rates of duckweed (Spirodela polyrrhiza) , 2000 .

[9]  Michel Loreau,et al.  From selection to complementarity: shifts in the causes of biodiversity–productivity relationships in a long-term biodiversity experiment , 2007, Proceedings of the Royal Society B: Biological Sciences.

[10]  F. Bazzaz,et al.  Interactive effects of diversity, nutrients and elevated CO2 on experimental plant communities , 2002 .

[11]  Nina Buchmann,et al.  Aboveground overyielding in grassland mixtures is associated with reduced biomass partitioning to belowground organs. , 2009, Ecology.

[12]  M. Scherer‐Lorenzen,et al.  Inorganic soil nitrogen under grassland plant communities of different species composition and diversity. , 2005 .

[13]  Masahiro Kato.  The Biology of Biodiversity , 2000, Springer Japan.

[14]  A. O. Rangel,et al.  Changes in the bacterial community structure in two-stage constructed wetlands with different plants for industrial wastewater treatment. , 2009, Bioresource technology.

[15]  S. An,et al.  Effects of plant and influent C:N:P ratio on microbial diversity in pilot-scale constructed wetlands , 2010 .

[16]  Chris C. Tanner,et al.  Plants for constructed wetland treatment systems — A comparison of the growth and nutrient uptake of eight emergent species , 1996 .

[17]  M. Loreau,et al.  Overyielding in grassland communities: testing the sampling effect hypothesis with replicated biodiversity experiments , 2002 .

[18]  Guenter Langergraber,et al.  Bacterial carbon utilization in vertical subsurface flow constructed wetlands. , 2008, Water research.

[19]  W. Ng,et al.  Constructed Tropical Wetlands with Integrated Submergent-Emergent Plants for Sustainable Water Quality Management , 2006, Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering.

[20]  Michel Loreau,et al.  Separating sampling and other effects in biodiversity experiments , 1998 .

[21]  A. Horne,et al.  Denitrification in constructed free-water surface wetlands: II. Effects of vegetation and temperature , 1999 .

[22]  Thammarat Koottatep,et al.  Influence of sand layer depth and percolate impounding regime on nitrogen transformation in vertical-flow constructed wetlands treating faecal sludge. , 2009, Water research.

[23]  B. Braskerud,et al.  Factors affecting phosphorus retention in small constructed wetlands treating agricultural non-point source pollution , 2002 .

[24]  F. Berendse,et al.  Positive effects of plant species diversity on productivity in the absence of legumes , 2003 .

[25]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[26]  O. T. Solbrig.  The Theory and Practice of the Science of Biodiversity: A Personal Assessment , 2000 .

[27]  L. Aarssen.  High productivity in grassland ecosystems : effected by species diversity or productive species ? , 1997 .

[28]  K. Huss-Danell,et al.  Nitrogen fixation in perennial forage legumes in the field , 2003, Plant and Soil.

[29]  R. W. Weaver,et al.  Improvement of domestic wastewater quality by subsurface flow constructed wetlands , 2000 .

[30]  Y. Ouyang,et al.  Removal of total nitrogen by Cyperus alternifolius from wastewaters in simulated vertical-flow constructed wetlands , 2009 .

[31]  W. Stanley Harpole,et al.  Mechanisms responsible for the positive diversity–productivity relationship in Minnesota grasslands , 2004 .

[32]  J. Skousen,et al.  Treatment of Domestic Wastewater by Three Plant Species in Constructed Wetlands , 2001 .

[33]  C. Keffala,et al.  Nitrogen and bacterial removal in constructed wetlands treating domestic waste water , 2005 .

[34]  A. Troumbis,et al.  The role of legumes as a component of biodiversity in a cross‐European study of grassland biomass nitrogen , 2002 .

[35]  Dong Liu,et al.  Constructed wetlands in China: recent developments and future challenges , 2009 .

[36]  C. Stratford,et al.  Variation in nutrient removal in three wetland blocks in relation to vegetation composition, inflow nutrient concentration and hydraulic loading , 2009 .

[37]  P Molle,et al.  Effect of reeds and feeding operations on hydraulic behaviour of vertical flow constructed wetlands under hydraulic overloads. , 2006, Water research.

[38]  D. Tilman,et al.  Plant functional composition influences rates of soil carbon and nitrogen accumulation , 2008 .

[39]  P. Reich,et al.  Diversity and Productivity in a Long-Term Grassland Experiment , 2001, Science.

[40]  M. Ritchie,et al.  THE EFFECT OF AQUATIC PLANT SPECIES RICHNESS ON WETLAND ECOSYSTEM PROCESSES , 2002 .

[41]  C. Roscher,et al.  Complementary nitrogen use among potentially dominant species in a biodiversity experiment varies between two years , 2008 .

[42]  P. Högberg,et al.  How plant diversity and legumes affect nitrogen dynamics in experimental grassland communities , 2002, Oecologia.

[43]  Peter M. Vitousek,et al.  Effects of plant composition and diversity on nutrient cycling , 1998 .

[44]  A. Hector,et al.  Darwin and the First Ecological Experiment , 2002, Science.

[45]  P. Reich,et al.  The Influence of Functional Diversity and Composition on Ecosystem Processes , 1997 .

[46]  Michael A. Huston,et al.  Hidden treatments in ecological experiments: re-evaluating the ecosystem function of biodiversity , 1997, Oecologia.

[47]  Bradley J. Cardinale,et al.  Effects of biodiversity on the functioning of trophic groups and ecosystems , 2006, Nature.

[48]  M. Loreau,et al.  Biodiversity and ecosystem functioning : synthesis and perspectives , 2002 .

[49]  Florent Chazarenc,et al.  Microbial processes influencing performance of treatment wetlands: A review , 2009 .

[50]  Pereira,et al.  Plant diversity and productivity experiments in european grasslands , 1999, Science.

[51]  B. Schmid,et al.  Diversity effects in early- and mid-successional species pools along a nitrogen gradient. , 2009, Ecology.

[52]  M. Ritchie,et al.  [Letters to nature] , 1975, Nature.

[53]  W. Stanley Harpole,et al.  Grassland species loss resulting from reduced niche dimension , 2007, Nature.

[54]  P. Balvanera,et al.  Quantifying the evidence for biodiversity effects on ecosystem functioning and services. , 2006, Ecology letters.

[55]  J. Knops,et al.  Mechanisms of plant species impacts on ecosystem nitrogen cycling , 2002 .

[56]  Robert W. Howarth,et al.  Nitrogen limitation on land and in the sea: How can it occur? , 1991 .

[57]  E. Schulze,et al.  The role of biodiversity for element cycling and trophic interactions: an experimental approach in a grassland community , 2004 .