scholarly journals Relationships between land use and nitrogen and phosphorus in New Zealand lakes

2011 ◽  
Vol 62 (2) ◽  
pp. 162 ◽  
Author(s):  
Jonathan M. Abell ◽  
Deniz Özkundakci ◽  
David P. Hamilton ◽  
Steven D. Miller
Keyword(s):  
Land Use ◽  
New Zealand ◽  
Nitrogen And Phosphorus ◽  
Nutrient Sources ◽  
Soil P ◽  
Agricultural Catchments ◽  
Relative Contribution ◽  
Naturally Occurring ◽  
Lake Catchment ◽  
The Relationship

Developing policies to address lake eutrophication requires an understanding of the relative contribution of different nutrient sources and of how lake and catchment characteristics interact to mediate the source–receptor pathway. We analysed total nitrogen (TN) and total phosphorus (TP) data for 101 New Zealand lakes and related these to land use and edaphic sources of phosphorus (P). We then analysed a sub-sample of lakes in agricultural catchments to investigate how lake and catchment variables influence the relationship between land use and in-lake nutrients. Following correction for the effect of co-variation amongst predictor variables, high producing grassland (intensive pasture) was the best predictor of TN and TP, accounting for 38.6% and 41.0% of variation, respectively. Exotic forestry and urban area accounted for a further 18.8% and 3.6% of variation in TP and TN, respectively. Soil P (representing naturally-occurring edaphic P) was negatively correlated with TP, owing to the confounding effect of pastoral land use. Lake and catchment morphology (zmax and lake : catchment area) and catchment connectivity (lake order) mediated the relationship between intensive pasture and in-lake nutrients. Mitigating eutrophication in New Zealand lakes requires action to reduce nutrient export from intensive pasture and quantifying P export from plantation forestry requires further consideration.

The effect of agriculture on cave-stream invertebrate communities

2017 ◽  
Vol 68 (11) ◽  
pp. 1999 ◽  
Author(s):  
Pierce M. McNie ◽  
Russell G. Death
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Ecological Health ◽  
Land Use Impacts ◽  
Invertebrate Community ◽  
Forested Catchments ◽  
Invertebrate Communities ◽  
Agricultural Catchments ◽  
Stream Communities ◽  
The Relationship

The impacts that land-use changes have on cave-stream fauna have not been considered widely in the investigations of land-use impacts on stream ecology. The present study examines how above-ground agriculture may influence cave-stream invertebrate communities. The invertebrate communities in four cave streams and their surface counterparts were sampled in 2014–2015, including two drained predominantly agricultural catchments and two drained forested catchments. These communities were examined alongside habitat and GIS land-use data to determine the relationship between above-ground land use and the stream communities. Invertebrate community composition and ecological health for surface streams was different between the agricultural and forest catchments. These differences were less pronounced within the cave-stream communities. Sedimentation was the principal agricultural stressor in the cave streams. The overall effects of agriculture were lower within the cave streams than on the surface; this is likely to be due to the reduced number of potentially deleterious stressors on cave streams.

scholarly journals Impact of Changes of Land Use on Water Quality, from Tropical Forest to Anthropogenic Occupation: A Multivariate Approach

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1518 ◽  
Author(s):  
Alexis Rodríguez-Romero ◽  
Axel Rico-Sánchez ◽  
Erick Mendoza-Martínez ◽  
Andrea Gómez-Ruiz ◽  
Jacinto Sedeño-Díaz ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Seasonal Variations ◽  
Cloud Forest ◽  
Ammonia Nitrogen ◽  
Fecal Coliforms ◽  
Vegetation Coverage ◽  
Nitrogen And Phosphorus ◽  
The Impact ◽  
The Relationship

Worldwide, it is acknowledged that changes of land use influence water quality; however, in tropical forests, the relationship between land use and water quality is still poorly understood. This study assessed spatial and seasonal variations in water quality, and the relationship between water quality and changes of land use in the Bobos-Nautla River, whose upper course runs across a patch of a tropical cloud forest. Spatial and seasonal variations in water quality and land use were assessed with multivariate tools. A cluster analysis, as well as a Principal Component Analysis (PCA-3D), identified three groups of sites: (1) an upper portion, which showed the best water quality and the broadest natural vegetation coverage; (2) a middle course, with high nitrogen and phosphorus concentrations associated with extensive agricultural uses; and (3) a lower course, characterized by the highest levels of total and fecal coliforms, as well as ammonia nitrogen, associated with the highest percentage of urbanization and human settlements. Our findings demonstrate the impact of changes of land use on water quality of rivers running through cloud forests in tropical zones, which are currently endangered ecosystems.

scholarly journals Agricultural phosphorus and water quality: sources, transport and management

1998 ◽  
Vol 7 (2) ◽  
pp. 297-314 ◽  
Author(s):  
Andrew Sharpley ◽  
William Gburek ◽  
Louise Heathwaite
Keyword(s):  
Water Quality ◽  
Land Use ◽  
East Central ◽  
Soil P ◽  
Agricultural Catchments ◽  
Central Pennsylvania ◽  
Chemical Factors ◽  
Mixed Land Use ◽  
Extractable Soil ◽  
Freshwater Eutrophication

Freshwater eutrophication is usually controlled by inputs of phosphorus (P). To identify critical sources of P export from agricultural catchments we investigated hydrological and chemical factors controlling P export from a mixed land use (30% wooded, 50% cultivated, 20% pasture) 39.5-ha catchment in east-central Pennsylvania, USA. Mehlich-3 extractable soil P, determined on a 30-m grid over the catchment, ranged from 7 to 788 mg kg-1. Generally, soils in wooded areas had low Mehlich-3P (

The influence of landscape spatial arrangement on nitrogen and phosphorus export in agricultural catchments

2021 ◽  
Author(s):  
Rémi Dupas ◽  
Antoine Casquin ◽  
Sen Gu ◽  
Gérard Gruau ◽  
Patrick Durand
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Spatial Configuration ◽  
Landscape Composition ◽  
Landscape Configuration ◽  
Agricultural Land Use ◽  
Nitrogen And Phosphorus ◽  
Nutrient Sources ◽  
Rural Landscapes ◽  
Flow Accumulation

<p>Nitrogen and Phosphorus losses from rural landscapes can cause eutrophication of inland and coastal waters. Here, we assessed the influence of the spatial configuration of nutrient sources on nitrate (NO<sub>3</sub><sup>-</sup>) and total phosphorus (TP) exports at the catchment scale. We analyzed NO<sub>3</sub><sup>-</sup> and TP in 19 headwater catchments (1 -14 km²) fortnightly during 17 months. The study catchments had similar soil type, climate, and farming systems but differed in their landscape composition (% agricultural land-use) and spatial configuration (field distance to streams & intersection with flow accumulation zones). We propose a landscape configuration index (LCI) that describes the spatial configuration of nutrient sources with regards to their hydrological distance to streams and flow accumulation zones. The LCI has two parameters that we calibrated to maximize rank correlation with median concentrations of TP and NO<sub>3</sub><sup>-</sup>. Results showed that NO<sub>3</sub><sup>-</sup> exports were correlated with %agricultural land-use whereas TP exports were better explained by the spatial configuration of agricultural fields. For a given landscape composition, landscape spatial configuration was highly heterogeneous at small scales (<10 km<sup>2</sup>) but became homogeneous at larger scales (>50 km<sup>2</sup>). This could explain why relationships between landscape composition and water quality parameters influenced by landscape spatial configuration break down below a certain size threshold.</p>

scholarly journals Nitrogen and phosphorus discharge from small agricultural catchments predicted from land use and hydroclimate

2018 ◽  
Vol 75 ◽  
pp. 260-268 ◽  
Author(s):  
Jaan Pärn ◽  
Hocine Henine ◽  
Kuno Kasak ◽  
Karin Kauer ◽  
Kristina Sohar ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrogen And Phosphorus ◽  
Agricultural Catchments

Isolation and identification of plant growth-promoting bacteria associated with tall fescue

2009 ◽  
pp. 211-216 ◽  
Author(s):  
J. Monk ◽  
E. Gerard ◽  
S. Young ◽  
K. Widdup ◽  
M. O'Callaghan
Keyword(s):  
New Zealand ◽  
Plant Growth ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Plant Growth Promoting Bacteria ◽  
Beneficial Bacteria ◽  
Isolation And Identification ◽  
Naturally Occurring ◽  
Plant Growth Promoting ◽  
Growth Promoting

Tall fescue (Festuca arundinacea) is a useful alternative to ryegrass in New Zealand pasture but it is slow to establish. Naturally occurring beneficial bacteria in the rhizosphere can improve plant growth and health through a variety of direct and indirect mechanisms. Keywords: rhizosphere, endorhiza, auxin, siderophore, P-solubilisation

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