scholarly journals Quantifying ecological effects of sedimentation in streams in differing land use management zones

2021 ◽  
Author(s):  
◽  
Debbie Mair
Keyword(s):  
Land Use ◽  
Fine Sediment ◽  
Sediment Deposition ◽  
Stream Habitat ◽  
Riparian Zones ◽  
Land Use Management ◽  
Sediment Delivery ◽  
Pulse Disturbance ◽  
Significant Difference ◽  
Press Disturbance

<p>This ecological and geomorphological assessment of Horokiri Stream and Ration Creek was conducted across four longitudinal zones to explore the effects of sediment delivery, run-off, channel form, riparian and in-stream habitat. The Horokiri Stream channel has moved approximately 7 metres westward over the last 20 years, with both banks now covered in long grass, flaxes, natives with a mix of tall canopy trees. Looking at stream, Spearman’s for Ration at Figure 27 (n = 16, rho -0.243, p = 0.36) as deposited sediment increased, MCI decreased, non-significant. Spearman’s for Horokiri at Figure 28 (n = 16, rho 0.247, p = 0.35) as MCI increased with sediment, non-significant. Results from upstream of the riparian zones showed more deposited fine sediment. However, within both the riparian zones the sediment deposition was much lower. The native riparian planting along the stream banks had a positive effect on reducing sedimentation. The findings support the concept that the restoration of riparian zones with buffer widths exceeding 10 metres can improve stream habitat and invertebrate health. There was no relationship between flow and deposition rate P(X2>241.84) = 0.24. Figure 24 shows deposited sediment on MCI depending on land use groups (X2 = 11.81, df = 4, p = 0.019). No statistically significant differences were found (comparing the effect of sediment between different land use management groups).  An experiment investigated a disturbance hypothesis in both Ration Creek and Horokiri Stream was conducted during February 2019. The experiment was designed to be long enough to study the effects of four weekly pulse flushing events created by scrapping the stream bed with a drain drag tool and the effects of a press sustained disturbance on the macroinvertebrate community. I measured the sediment and the macroinvertebrate captured in each trap within the experiment site every seven days. My prediction was that macroinvertebrate communities subject to sustained fine sediment delivery (press disturbance) are affected by simulated pulse flushing events (pulse disturbance). A comparison of sediment depositional rate before and after the manipulative experiment (Figure 36) showed higher sediment deposition after the pulse flushing events (1.55 W/A/D) compared to before during the assessment phase (0.88 W/A/D) in Horokiri (t = 2.35, df = 8.95, p = 0.04), but no significant difference before (1.57 W/A/D) or after (1.38 W/A/D) in Ration (t = -0.818, df = 7.71, p = 0.44). It appeared that the smaller riparian buffer width of 2-5m at Ration Creek did not limit sediment deposition. The effects of sediment disturbance in the experiment reflect the rapid ability of macroinvertebrates to respond to sediment by drifting out of unsuitable areas. The weekly pulse disturbance events resulted in increased sediment deposition compared to the background levels of sediment deposition (indicative of a press disturbance) in both streams. As pulse disturbance events increased, the number of macroinvertebrate taxa decreased. Horokiri Stream invertebrate communities declined by 33% compared to Ration Creek which declined by 50%.</p>

scholarly journals Quantifying ecological effects of sedimentation in streams in differing land use management zones

2021 ◽  
Author(s):  
◽  
Debbie Mair
Keyword(s):  
Land Use ◽  
Fine Sediment ◽  
Sediment Deposition ◽  
Stream Habitat ◽  
Riparian Zones ◽  
Land Use Management ◽  
Sediment Delivery ◽  
Pulse Disturbance ◽  
Significant Difference ◽  
Press Disturbance

<p>This ecological and geomorphological assessment of Horokiri Stream and Ration Creek was conducted across four longitudinal zones to explore the effects of sediment delivery, run-off, channel form, riparian and in-stream habitat. The Horokiri Stream channel has moved approximately 7 metres westward over the last 20 years, with both banks now covered in long grass, flaxes, natives with a mix of tall canopy trees. Looking at stream, Spearman’s for Ration at Figure 27 (n = 16, rho -0.243, p = 0.36) as deposited sediment increased, MCI decreased, non-significant. Spearman’s for Horokiri at Figure 28 (n = 16, rho 0.247, p = 0.35) as MCI increased with sediment, non-significant. Results from upstream of the riparian zones showed more deposited fine sediment. However, within both the riparian zones the sediment deposition was much lower. The native riparian planting along the stream banks had a positive effect on reducing sedimentation. The findings support the concept that the restoration of riparian zones with buffer widths exceeding 10 metres can improve stream habitat and invertebrate health. There was no relationship between flow and deposition rate P(X2>241.84) = 0.24. Figure 24 shows deposited sediment on MCI depending on land use groups (X2 = 11.81, df = 4, p = 0.019). No statistically significant differences were found (comparing the effect of sediment between different land use management groups).  An experiment investigated a disturbance hypothesis in both Ration Creek and Horokiri Stream was conducted during February 2019. The experiment was designed to be long enough to study the effects of four weekly pulse flushing events created by scrapping the stream bed with a drain drag tool and the effects of a press sustained disturbance on the macroinvertebrate community. I measured the sediment and the macroinvertebrate captured in each trap within the experiment site every seven days. My prediction was that macroinvertebrate communities subject to sustained fine sediment delivery (press disturbance) are affected by simulated pulse flushing events (pulse disturbance). A comparison of sediment depositional rate before and after the manipulative experiment (Figure 36) showed higher sediment deposition after the pulse flushing events (1.55 W/A/D) compared to before during the assessment phase (0.88 W/A/D) in Horokiri (t = 2.35, df = 8.95, p = 0.04), but no significant difference before (1.57 W/A/D) or after (1.38 W/A/D) in Ration (t = -0.818, df = 7.71, p = 0.44). It appeared that the smaller riparian buffer width of 2-5m at Ration Creek did not limit sediment deposition. The effects of sediment disturbance in the experiment reflect the rapid ability of macroinvertebrates to respond to sediment by drifting out of unsuitable areas. The weekly pulse disturbance events resulted in increased sediment deposition compared to the background levels of sediment deposition (indicative of a press disturbance) in both streams. As pulse disturbance events increased, the number of macroinvertebrate taxa decreased. Horokiri Stream invertebrate communities declined by 33% compared to Ration Creek which declined by 50%.</p>

Can SPLUMA Play a Role in Transforming Spatial Injustice to Spatial Justice in Housing in South Africa?

2017 ◽  
Vol 30 (1) ◽  
pp. 26-41 ◽  
Author(s):  
Jeannie Van Wyk
Keyword(s):  
South Africa ◽  
Land Use ◽  
Land Reform ◽  
Spatial Planning ◽  
National Development ◽  
Well Being ◽  
Spatial Development ◽  
Land Use Management ◽  
Spatial Justice ◽  
Spatial Environment

Our spatial environment is one of the most important determinants of our well-being and life chances. It relates to schools, opportunities, businesses, recreation and access to public services. Spatial injustice results where discrimination determines that spatial environment. Since Apartheid in South Africa epitomised the notion of spatial injustice, tools and instruments are required to transform spatial injustice into spatial justice. One of these is the employment of principles of spatial justice. While the National Development Plan (NDP) recognised that all spatial development should conform to certain normative principles and should explicitly indicate how the requirements of these should be met, the Spatial Planning and Land Use Management Act 16 of 2013 (SPLUMA) contains a more concrete principle of spatial justice. It echoes aspects of both the South African land reform programme and global principles of spatial justice. Essentially section 7(a) of SPLUMA entails three components: (1) redressing past spatial imbalances and exclusions; (2) including people and areas previously excluded and (3) upgrading informal areas and settlements. SPLUMA directs municipalities to apply the principle in its spatial development frameworks, land use schemes and, most importantly, in decision-making on development applications. The aim of this article is to determine whether the application of this principle in practice can move beyond the confines of spatial planning and land use management to address the housing issue in South Africa. Central to housing is section 26 of the Constitution, that has received the extensive attention of the Constitutional Court. The court has not hesitated to criticize the continuing existence of spatial injustice, thus contributing to the transformation of spatial injustice to spatial justice. Since planning, housing and land reform are all intertwined not only the role of SPLUMA, but also the NDP and the myriad other policies, programmes and legislation that are attempting to address the situation are examined and tested against the components of the principle of spatial justice in SPLUMA.

Land-Use Management and Carbon Sequestering in Sub-Saharan Africa

1992 ◽  
Vol 22 (3) ◽  
pp. 199-210 ◽  
Author(s):  
R. D. Perlack ◽  
R. L. Graham ◽  
A. M. G. Prasad
Keyword(s):  
Land Use ◽  
Sub Saharan Africa ◽  
Land Use Management ◽  
Carbon Sequestering ◽  
Sub Saharan

scholarly journals Land-Use Impact on Stand Structure and Fruit Yield of Tamarindus indica L. in the Drylands of Southeastern Ethiopia

Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 408
Author(s):  
Gizachew Zeleke ◽  
Tatek Dejene ◽  
Wubalem Tadesse ◽  
Pablo Martín-Pinto
Keyword(s):  
Land Use ◽  
Stand Structure ◽  
Fruit Production ◽  
Tree Density ◽  
Fruit Yield ◽  
Tamarindus Indica ◽  
Land Use Types ◽  
Significant Difference ◽  
Management Plans ◽  
Baseline Information

In this study, we evaluated stand status, dendrometric variables, and fruit production of Tamarind (Tamarindus indica L.) trees growing in bushland and farmland-use types in dryland areas of Ethiopia. The vegetation survey was conducted using the point-centered quarter method. The fruit yield of 54 trees was also evaluated. Tree density and fruit production in ha were estimated. There was a significant difference in Tamarind tree density between the two land-use types (p = 0.01). The mean fruit yield of farmland trees was significantly higher than that of bushland trees. However, Tamarind has unsustainable structure on farmlands. Differences in the dendrometric characteristics of trees were also observed between the two land-use types. Predictive models were selected for Tamarind fruit yield estimations in both land-use types. Although the majority of farmland trees produced <5000 fruit year−1, the selection of Tamarind germplasm in its natural ranges could improve production. Thus, the development of management plans to establish stands that have a more balanced diameter structure and thereby ensure continuity of the population and fruit yields is required in this area, particularly in the farmlands. This baseline information could assist elsewhere in areas that are facing similar challenges for the species due to land-use change.

scholarly journals Assessment of Seasonal Variability in Soil Nutrients and Its Impact on Soil Quality under Different Land Use Systems of Lower Shiwalik Foothills of Himalaya, India

2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Surface Soil ◽  
Sandy Loam ◽  
Monsoon Season ◽  
Soil Layer ◽  
Seasonal Effects ◽  
Land Use Systems ◽  
Post Monsoon ◽  
Significant Difference

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.

scholarly journals Impact of Land Use Change on Water Conservation: A Case Study of Zhangjiakou in Yongding River

2020 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Tianshi Pan ◽  
Lijun Zuo ◽  
Zengxiang Zhang ◽  
Xiaoli Zhao ◽  
Feifei Sun ◽  
...  
Keyword(s):  
Land Use ◽  
Sustainable Development ◽  
Water Conservation ◽  
Land Use Changes ◽  
Water Yield ◽  
Special Focus ◽  
Hydrological Process ◽  
Significant Difference ◽  
The Impact ◽  
Yongding River

The implementation of ecological projects can largely change regional land use patterns, in turn altering the local hydrological process. Articulating these changes and their effects on ecosystem services, such as water conservation, is critical to understanding the impacts of land use activities and in directing future land planning toward regional sustainable development. Taking Zhangjiakou City of the Yongding River as the study area—a region with implementation of various ecological projects—the impact of land use changes on various hydrological components and water conservation capacity from 2000 to 2015 was simulated based on a soil and water assessment tool model (SWAT). An empirical regression model based on partial least squares was established to explore the contribution of different land use changes on water conservation. With special focus on the forest having the most complex effects on the hydrological process, the impacts of forest type and age on the water conservation capacity are discussed on different scales. Results show that between 2000 and 2015, the area of forest, grassland and cultivated land decreased by 0.05%, 0.98% and 1.64%, respectively, which reduces the regional evapotranspiration (0.48%) and soil water content (0.72%). The increase in settlement area (42.23%) is the main reason for the increase in water yield (14.52%). Most land use covered by vegetation has strong water conservation capacity, and the water conservation capacity of the forest is particularly outstanding. Farmland and settlements tend to have a negative effect on water conservation. The water conservation capacity of forest at all scales decreased significantly with the growth of forest (p < 0.05), while the water conservation capacity of different tree species had no significant difference. For the study area, increasing the forest area will be an effective way to improve the water conservation function, planting evergreen conifers can rapidly improve the regional water conservation capacity, while planting deciduous conifers is of great benefit to long-term sustainable development.

Sign in / Sign up

Export Citation Format

Share Document