scholarly journals Influence of vegetation type and temperature on the performance of constructed wetlands for nutrient removal

2017 ◽  
Vol 77 (3) ◽  
pp. 829-837 ◽  
Author(s):  
Hui Zhu ◽  
Qing-wei Zhou ◽  
Bai-xing Yan ◽  
Yin-xiu Liang ◽  
Xiang-fei Yu ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Nutrient Removal ◽  
Environmental Temperature ◽  
Rhizosphere Soil ◽  
Vegetation Type ◽  
Lythrum Salicaria ◽  
Vegetation Types ◽  
Sharp Decline ◽  
Average Temperature ◽  
Different Temperatures

Abstract In this study, the influence of vegetation type and environmental temperature on performance of constructed wetlands (CWs) was investigated. Results of vegetation types indicated that the removal of most nutrients in polyculture was greater than those in monoculture and unplanted control. The greatest removal percentages of NH4+-N, total nitrogen (TN) and total phosphorus (TP) in polyculture were 98.7%, 98.5%, and 92.6%, respectively. In experiments of different temperatures, the removal percentages of NH4+-N, NO3−-N, TN and TP in all CWs tended to decrease with the decline of temperature. Especially, a sharp decline in the removal percentages of NO3−-N (decreased by above 13.8%) and TN (decreased by above 7.9%) of all CWs was observed at low temperature (average temperature of 8.9 °C). Overall, the performance of CWs was obviously influenced by temperature, and the polyculture still showed best performance in the removal of nitrogen when the average temperature dropped to 19.8 °C. Additionally, the variations of urease activities in rhizosphere soil tended to decrease with the decreasing temperature. Overall, a substantial enhancement for nitrogen and TP removal in polyculture (Canna indica + Lythrum salicaria) was observed. In conclusion, CW cultivated with polyculture was a good strategy for enhancing nutrient removal when temperature was above 19.8 °C.

Variability of treatment performance in constructed wetlands

1995 ◽  
Vol 32 (3) ◽  
pp. 241-250 ◽  
Author(s):  
E. Kuehn ◽  
James A. Moore
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Vegetation Type ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Total Suspended Solids ◽  
Matched Pairs ◽  
Vegetation Types ◽  
Treatment Performance ◽  
Over Time

Eight constructed wetland ponds treating pulp mill effluent were monitored for removal of biochemical oxygen demand (BOD) and total suspended solids (TSS). Matched pairs of ponds differed by retention times and vegetation types. Analysis showed that variations over time between pairs of similar ponds were small. Performance of similarly designed constructed wetlands should be similar. TSS effluent concentrations varied by vegetation type, while BOD effluent concentrations varied with season.

scholarly journals Satellite monitoring of different vegetation types by differential optical absorption spectroscopy (DOAS) in the red spectral range

2007 ◽  
Vol 7 (1) ◽  
pp. 69-79 ◽  
Author(s):  
T. Wagner ◽  
S. Beirle ◽  
T. Deutschmann ◽  
M. Grzegorski ◽  
U. Platt
Keyword(s):  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Spectral Range ◽  
Near Infrared ◽  
Vegetation Type ◽  
Differential Optical Absorption Spectroscopy ◽  
Trace Gas ◽  
Satellite Monitoring ◽  
Optical Absorption Spectroscopy ◽  
Vegetation Types

Abstract. A new method for the satellite remote sensing of different types of vegetation and ocean colour is presented. In contrast to existing algorithms relying on the strong change of the reflectivity in the red and near infrared spectral region, our method analyses weak narrow-band (few nm) reflectance structures (i.e. "fingerprint" structures) of vegetation in the red spectral range. It is based on differential optical absorption spectroscopy (DOAS), which is usually applied for the analysis of atmospheric trace gas absorptions. Since the spectra of atmospheric absorption and vegetation reflectance are simultaneously included in the analysis, the effects of atmospheric absorptions are automatically corrected (in contrast to other algorithms). The inclusion of the vegetation spectra also significantly improves the results of the trace gas retrieval. The global maps of the results illustrate the seasonal cycles of different vegetation types. In addition to the vegetation distribution on land, they also show patterns of biological activity in the oceans. Our results indicate that improved sets of vegetation spectra might lead to more accurate and more specific identification of vegetation type in the future.

Body size and mean individual biomass variation of ground-beetles community (Coleoptera: Carabidae) as a response to increasing altitude and associated vegetation types in mountainous ecosystem

Biologia ◽  
2017 ◽  
Vol 72 (9) ◽  
Author(s):  
Aleksandra Cvetkovska-Gjorgjievska ◽  
Slavčo Hristovski ◽  
Dana Prelić ◽  
Lucija Šerić Jelaska ◽  
Valentina Slavevska-Stamenković ◽  
...  
Keyword(s):  
Body Size ◽  
Altitudinal Gradient ◽  
Vegetation Type ◽  
Ground Beetle ◽  
Vegetation Types ◽  
Forest Stands ◽  
Geologic History ◽  
White Oak ◽  
Mountain Ecosystems ◽  
Individual Biomass

AbstractCarabid fauna is not sufficiently explored in Central and Western Balkan areas, especially in mountain ecosystems with unique biodiversity which is a result of specific environmental factors and geologic history. Furthermore, distribution of species and adaptation to varying environmental parameters change along the altitudinal gradients. All this highlights the need for biodiversity and ecological studies in order to assess the state of the mountain ecosystems and conservation significance. Carabids as good bioindicator group can be used as a tool for monitoring those changes. The aim of this study was to analyse the differences of body size distribution and mean individual biomass (MIB) of ground beetle assemblages as a response of changing conditions and vegetation types along an altitudinal gradient on Belasitsa Mountain in south Macedonia. Both parameters significantly decreased with increasing altitude and were consequently associated with the vegetation type. Larger bodied individuals and higher values of MIB were recorded in the white oak and oriental hornbeam forest stands with the values decreasing in sessile oak forests towards submontane and montane beech forest stands. This research yielded first list of carabid species inhabiting Belasitsa Mountain with insight of carabid body length and biomass distribution along altitudinal gradient.

Soil Moisture Responses Under Different Vegetation Types to Winter Rainfall Events in a Humid Karst Region

2021 ◽  
Author(s):  
Weihong Yan ◽  
Qiuwen Zhou ◽  
Dawei Peng ◽  
Xiaocha Wei ◽  
Xin Tang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Vegetation Type ◽  
Arable Land ◽  
Karst Region ◽  
Control Group ◽  
Vegetation Types ◽  
Recovery Model ◽  
Winter Rainfall ◽  
Rainfall Events ◽  
Karst Ecosystems

Abstract Humid karst ecosystems are fragile, with precipitation being the main source of soil moisture recharge. The process of soil moisture recharge and usage varies by vegetation type. To analyze the dynamics of soil moisture under different vegetation types during rainfall events, we continuously monitored soil moisture in arable land, grassland, shrub, and forest areas at 10-minute intervals from November 6, 2019, to January 6, 2020.The arable land was used as a control group. Soil moisture under the different vegetation types responded to light, moderate, and rainstorm events with large rainfall amounts. However, only the soil moisture in the grassland areas responded to a light rainfall event with a rainfall amount of 0.87 mm. The largest soil moisture recharge (12.63 mm) and decline (2.08%) were observed for the grassland areas, with the smallest observed for the forest areas. While the grassland areas showed the greatest decline in soil moisture following rainfall, they were more easily recharged during the winter rainfall events. Soil moisture in forests and shrubs was less recharged than in grasslands but also declined less. Therefore, forests and shrubs are better at retaining soil moisture in winter, which is informative for the formulation of a regional vegetation recovery model.

scholarly journals A proposed procedure for the analysis of large phytosociological data sets in the classification of South African grasslands

Koedoe ◽  
1995 ◽  
Vol 38 (1) ◽  
Author(s):  
G.J. Bredenkamp ◽  
H. Bezuidenhout
Keyword(s):  
South African ◽  
Plant Communities ◽  
Vegetation Type ◽  
Second Step ◽  
Data Sets ◽  
Vegetation Types ◽  
Related Plant ◽  
Single Cluster ◽  
Synoptic Table

A procedure for the effective classification of large phytosociological data sets, and the combination of many data sets from various parts of the South African grasslands is demonstrated. The procedure suggests a region by region or project by project treatment of the data. The analyses are performed step by step to effectively bring together all releves of similar or related plant communities. The first step involves a separate numerical classification of each subset (region), and subsequent refinement by Braun- Blanquet procedures. The resulting plant communities are summarised in a single synoptic table, by calculating a synoptic value for each species in each community. In the second step all communities in the synoptic table are classified by numerical analysis, to bring related communities from different regions or studies together in a single cluster. After refinement of these clusters by Braun-Blanquet procedures, broad vegetation types are identified. As a third step phytosociological tables are compiled for each iden- tified broad vegetation type, and a comprehensive abstract hierarchy constructed.

Determinants of spatial variation in fire return period in a semiarid African savanna

2011 ◽  
Vol 20 (4) ◽  
pp. 540 ◽  
Author(s):  
T. G. O'Connor ◽  
C. M. Mulqueeny ◽  
P. S. Goodman
Keyword(s):  
Spatial Variation ◽  
Return Period ◽  
Vegetation Type ◽  
Fire Frequency ◽  
Fuel Load ◽  
Annual Rainfall ◽  
Vegetation Types ◽  
Terrestrial Vegetation ◽  
African Savanna ◽  
Data Set

Fire pattern is predicted to vary across an African savanna in accordance with spatial variation in rainfall through its effects on fuel production, vegetation type (on account of differences in fuel load and in flammability), and distribution of herbivores (because of their effects on fuel load). These predictions were examined for the 23 651-ha Mkuzi Game Reserve, KwaZulu-Natal, based on a 37-year data set. Fire return period varied from no occurrence to a fire every 1.76 years. Approximately 75% of the reserve experienced a fire approximately every 5 years, 25% every 4.1–2.2 years and less than 1% every 2 years on average. Fire return period decreased in relation to an increase in mean annual rainfall. For terrestrial vegetation types, median fire return periods decreased with increasing herbaceous biomass, from forest that did not burn to grasslands that burnt every 2.64 years. Fire was absent from some permanent wetlands but seasonal wetlands burnt every 5.29 years. Grazer biomass above 0.5 animal units ha–1 had a limiting influence on the maximum fire frequency of fire-prone vegetation types. The primary determinant of long-term spatial fire patterns is thus fuel load as determined by mean rainfall, vegetation type, and the effects of grazing herbivores.

scholarly journals Carbon and nitrogen dynamics and greenhouse gas emissions in constructed wetlands treating wastewater: a review

2016 ◽  
Vol 20 (1) ◽  
pp. 109-123 ◽  
Author(s):  
M. M. R. Jahangir ◽  
K. G. Richards ◽  
M. G. Healy ◽  
L. Gill ◽  
C. Müller ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Empirical Evidence ◽  
Constructed Wetlands ◽  
Nutrient Removal ◽  
Management Practices ◽  
N2o Emissions ◽  
Knowledge Gaps ◽  
Ch4 Emissions ◽  
N Removal ◽  
C And N

Abstract. The removal efficiency of carbon (C) and nitrogen (N) in constructed wetlands (CWs) is very inconsistent and frequently does not reveal whether the removal processes are due to physical attenuation or whether the different species have been transformed to other reactive forms. Previous research on nutrient removal in CWs did not consider the dynamics of pollution swapping (the increase of one pollutant as a result of a measure introduced to reduce a different pollutant) driven by transformational processes within and around the system. This paper aims to address this knowledge gap by reviewing the biogeochemical dynamics and fate of C and N in CWs and their potential impact on the environment, and by presenting novel ways in which these knowledge gaps may be eliminated. Nutrient removal in CWs varies with the type of CW, vegetation, climate, season, geographical region, and management practices. Horizontal flow CWs tend to have good nitrate (NO3−) removal, as they provide good conditions for denitrification, but cannot remove ammonium (NH4+) due to limited ability to nitrify NH4+. Vertical flow CWs have good NH4+ removal, but their denitrification ability is low. Surface flow CWs decrease nitrous oxide (N2O) emissions but increase methane (CH4) emissions; subsurface flow CWs increase N2O and carbon dioxide (CO2) emissions, but decrease CH4 emissions. Mixed species of vegetation perform better than monocultures in increasing C and N removal and decreasing greenhouse gas (GHG) emissions, but empirical evidence is still scarce. Lower hydraulic loadings with higher hydraulic retention times enhance nutrient removal, but more empirical evidence is required to determine an optimum design. A conceptual model highlighting the current state of knowledge is presented and experimental work that should be undertaken to address knowledge gaps across CWs, vegetation and wastewater types, hydraulic loading rates and regimes, and retention times, is suggested. We recommend that further research on process-based C and N removal and on the balancing of end products into reactive and benign forms is critical to the assessment of the environmental performance of CWs.

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