scholarly journals Why a landscape view is important: nearby urban and agricultural land affects bird abundances in protected areas

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10719
Author(s):  
Gregory Duncan Duckworth ◽  
Res Altwegg

Protected areas are one of the primary conservation tools used worldwide. However, they are often embedded in a landscape that is intensely used by people, such as for agriculture or urban development. The proximity of these land-use types to protected areas can potentially affect the ecological effectiveness (or conservation effectiveness) of protected areas. In this article, we examine to what degree adjacent agricultural and urban land uses affect the ecological effectiveness of protected areas over the greater Gauteng region of South Africa. We selected 198 common, resident bird species, and analysed detection/non-detection data for these species collected over regular grid cells (approximately 61 km2 in area). For each species, we estimated abundance per grid cell with the Royle-Nichols model in relation to the proportion of protected area as a covariate. Our study focused on how this relationship between proportion of protected area and abundance (which we term the ‘protection–abundance relationship’) changed as a function of other land-use types in the grid cell. Specifically, we examined the interaction effects between protected area and both urban and agricultural land-use type per grid cell on bird abundance. We assigned each species to one of seven guilds, namely: frugivores, gleaners, granivores, ground-feeders, hawkers, predators and vegivores, and examined how the protection–abundance relationship varied across guilds in relation to agriculture and urban area. As urban area within a grid cell increased, the protection–abundance relationship became more positive for 58% of all species. At the level of guilds, the protection–abundance relationship became more positive for two guilds (granivores and ground-feeders), more negative for frugivores, and remained unchanged for the other four guilds (gleaners, hawkers, predators and vegivores). As agricultural area within a grid cell increased, the protection–abundance relationship became more positive for 49% of all species. At the guild level, the protection–abundance relationship became more positive for six guilds (frugivores, gleaners, ground-feeders, hawkers, predators and vegivores) and remained unchanged for the granivores. Our results show land-use type near protected areas modified the effect protected areas had on bird abundances, and hence the ecological effectiveness of protected areas. Our results suggest that protected areas should be viewed as constituents within the landscape, rather than islands of protection.

2019 ◽  
Vol 10 (2) ◽  
pp. 32-37
Author(s):  
Farida Begum ◽  
Muneer Alam ◽  
Sameena Mumtaz ◽  
Manzoor Ali ◽  
Seema Wafee ◽  
...  

Soil quality is a fundamental component of environmental quality and impact of land use is also a keydetrimental factor in today’s rapid urbanization era. The study aims to evaluate the effects of different land-use type on selected soil quality indicators. Sixty soil samples were collected from various land use types, i.e, pasture, forest and agriculture from a depth of 0-15cm. Analysis of variance (ANOVA) showed that the land use type significantly affected the soil’s physical and chemical properties. The moisture content was significantly higher (p<0.001) in the pasture (41.7%) than the forest (26.2%) and lowest in agricultural land (14.4%). The soil pH was significantly higher or slightly alkaline for agriculture (7.8), while for pasture (6.5) and forest (6.1), it was found to be slightly acidic. Electric conductivity (EC) and bulk density (BD) did not vary significantly with land use type, but the EC followed the decreasing order: forest (203.7μS/cm) < pasture (235μS/cm) < agriculture (328.7μS/cm). The soil organic matter (SOM) and soil organic carbon (SOC) significantly (p<0.05) differed with land use type and found in the order: forest (3.0%, 1.3 %) > pasture land (2.9%, 1.2%) > arable land (2.5%, 1.1%). NO3-N, available P and exchangeable K did not vary significantly across land use types. However, mean values were higher for agriculture (10.2mg/kg, 4.5mg/kg, 66mg/kg) than forest (10mg/kg,3.5mg/kg, 60mg/kg) and pasture (9.8mg/kg, 4.3, 60.2mg/kg). Alpine soils are good ecological indicators because of vulnerability to environmental change, therefore, regular monitoring of soil properties along with carbon stocks is essential to maintain soil health, enhance agricultural productivity and sustain agroecosystems.


2018 ◽  
Vol 11 (1) ◽  
pp. 19-34
Author(s):  
Karel Poprach ◽  
Libor Opluštil ◽  
František Krause ◽  
Ivo Machar

Abstract The Little Owl is currently endangered bird species of agricultural lowland areas in Central Europe. Nesting sites of the Little Owl are often old trees as well as buildings and quarries with suitable nesting cavities. The Little Owl has severely declined in a major part of Europe during the past decades. Information on habitat requirements of the Little Owl and data related to land-use changes at nest sites (covering both the breeding and foraging habitats) are needed for conservation programmes aimed at this bird species. Land-use changes in farmland rank among frequently discussed negative factors causing the population decline of the Little Owl. The aim of this study is to analyse land-use changes at nest sites of the Little Owl in the South-Moravian region (Czech Republic) between the years 1976/1977 and 2014. In both studied periods (1976/1977 and 2014), the most important land-use type within 500 m from the nest sites of the Little Owl was arable land (66.94 % – 62.25 %), followed by built-up areas (19.97 % –22.41 %), while the other land-use types made up less than 5 %. The proportion of the particular land-use type did not change significantly between the years 1976/1977 and 2014. The most important change in comparison with the period 1976/1977 was the decrease in the area of arable land by 4.69 % and that of orchards and gardens by 1.99 %, while the surface of built-up areas increased slightly by 2.45 % and that of meadows and pastures by 1.5 %. The analysis shows that at the known nest sites of the Little Owl in the South-Moravian region (Czech Republic), there were no significant changes in the proportion of the particular land-use types within 500 m from the nests between the years 1976/1977 and 2014. Based on these results, we can conclude that in comparison with the availability of nest sites, which seems to be the important limiting factor for the occurrence and population density of the Little Owl, land-use changes in study area were not very important factor influencing decline of the Little Owl.


2020 ◽  
Vol 12 (18) ◽  
pp. 2919
Author(s):  
Ann-Kathrin Holtgrave ◽  
Norbert Röder ◽  
Andrea Ackermann ◽  
Stefan Erasmi ◽  
Birgit Kleinschmit

Agricultural vegetation development and harvest date monitoring over large areas requires frequent remote sensing observations. In regions with persistent cloud coverage during the vegetation season this is only feasible with active systems, such as SAR, and is limited for optical data. To date, optical remote sensing vegetation indices are more frequently used to monitor agricultural vegetation status because they are easily processed, and the characteristics are widely known. This study evaluated the correlations of three Sentinel-2 optical indices with Sentinel-1 SAR indices over agricultural areas to gain knowledge about their relationship. We compared Sentinel-2 Normalized Difference Vegetation Index, Normalized Difference Water Index, and Plant Senescence Radiation Index with Sentinel-1 SAR VV and VH backscatter, VH/VV ratio, and Sentinel-1 Radar Vegetation Index. The study was conducted on 22 test sites covering approximately 35,000 ha of four different main European agricultural land use types, namely grassland, maize, spring barley, and winter wheat, in Lower Saxony, Germany, in 2018. We investigated the relationship between Sentinel-1 and Sentinel-2 indices for each land use type considering three phenophases (growing, green, senescence). The strength of the correlations of optical and SAR indices differed among land use type and phenophase. There was no generic correlation between optical and SAR indices in our study. However, when the data were split by land use types and phenophases, the correlations increased remarkably. Overall, the highest correlations were found for the Radar Vegetation Index and VH backscatter. Correlations for grassland were lower than for the other land use types. Adding auxiliary data to a multiple linear regression analysis revealed that, in addition to land use type and phenophase information, the lower quartile and median SAR values per field, and a spatial variable, improved the models. Other auxiliary data retrieved from a digital elevation model, Sentinel-1 orbit direction, soil type information, and other SAR values had minor impacts on the model performance. In conclusion, despite the different nature of the signal generation, there were distinct relationships between optical and SAR indices which were independent of environmental variables but could be stratified by land use type and phenophase. These relationships showed similar patterns across different test sites. However, a regional clustering of landscapes would significantly improve the relationships.


Author(s):  
Farida Begum ◽  
Muneer Alam ◽  
Sameena Mumtaz ◽  
Manzoor Ali ◽  
Seema Wafee ◽  
...  

Soil quality is a fundamental component of environmental quality and impact of land use is also a keydetrimental factor in today’s rapid urbanization era. The study aims to evaluate the effects of different land-use type on selected soil quality indicators. Sixty soil samples were collected from various land use types, i.e, pasture, forest and agriculture from a depth of 0-15cm. Analysis of variance (ANOVA) showed that the land use type significantly affected the soil’s physical and chemical properties. The moisture content was significantly higher (p<0.001) in the pasture (41.7%) than the forest (26.2%) and lowest in agricultural land (14.4%). The soil pH was significantly higher or slightly alkaline for agriculture (7.8), while for pasture (6.5) and forest (6.1), it was found to be slightly acidic. Electric conductivity (EC) and bulk density (BD) did not vary significantly with land use type, but the EC followed the decreasing order: forest (203.7μS/cm) < pasture (235μS/cm) < agriculture (328.7μS/cm). The soil organic matter (SOM) and soil organic carbon (SOC) significantly (p<0.05) differed with land use type and found in the order: forest (3.0%, 1.3 %) > pasture land (2.9%, 1.2%) > arable land (2.5%, 1.1%). NO3-N, available P and exchangeable K did not vary significantly across land use types. However, mean values were higher for agriculture (10.2mg/kg, 4.5mg/kg, 66mg/kg) than forest (10mg/kg,3.5mg/kg, 60mg/kg) and pasture (9.8mg/kg, 4.3, 60.2mg/kg). Alpine soils are good ecological indicators because of vulnerability to environmental change, therefore, regular monitoring of soil properties along with carbon stocks is essential to maintain soil health, enhance agricultural productivity and sustain agroecosystems.


Author(s):  
Durga D. Poudel ◽  
Timothy W. Duex ◽  
Roshan Poudel

Drinking water security is increasingly becoming a global concern in recent decades. The mid-hill region of Nepal is also experiencing serious water shortages in recent years. In order to assess the availability of drinking water in the mid-hill regions of Nepal, we studied hydrogeology, land use types and collected water samples from 30 springs in Kavre, Kahmandu Valley, Nuwakot and Tanahu in Nepal between July 17-September 12, 2017. For each sampling spring, while surrounding land use type (mixed, agriculture, urban, vegetation) and spring type (fracture, depression, contact) were determined through field observation, the field pH, conductivity and temperature was determined using relevant probes and thermometers. Water samples were collected in 1L and 165mL plastic bottles for chemical and total coliform determination, respectively, in the lab. Bottles were rinsed twice using spring water before filling them with sample water, then stored in an ice chest, and brought to the lab. In the laboratory, turbidity, conductivity, Ca, Mg, HCO3, SO4, Na, NO3, Cl, Fe, As, and total coliform were determined using standard methods. Spring water in agricultural areas showed significantly higher suspended solids compared to other land use types whereas spring water in urban areas showed significantly higher dissolved substances. By spring type, turbidity and conductivity values and the concentration of dissolved constituents (Ca, Mg, HCO3, SO4, NO3, and Cl) were ranked in the order of fracture < contact < depression. Na and Fe concentration were in the order of fracture = contact < depression. By land-use type, conductivity and dissolved constituents (Ca, Mg, HCO3) were in the order of agriculture < vegetation < mixed < urban. Whereas urban land use had the highest values for SO4, Na, NO3, and Cl, other land use types showed variable order. Fe concentration was ranked in the order of urban < mixed < vegetation < agriculture. Total coliform was in the order of mixed < agriculture < urban < vegetation. These results indicate that land use type and surface condition, which is possibly associated with human activities, heavily affect spring water properties in the region. These results suggest that drinking water security of mid-hill region of Nepal is threatened heavily due to poor spring water quality. Protection of drinking water sources should be specific to land use type and activities around the springs. Index Terms— three to six pertinent, specific to the paper, keywords added after the abstract, separated by commas.


Author(s):  
Mesfin Kassa ◽  
Wassie Haile ◽  
fassile kebede

Quantity-intensity characteristics are among conventional approaches for studying potassium dynamics and its availability; this was assessed to determine availability in four districts: namely, Sodo Zuria, Damot Gale, Damot Sore, and Boloso Sore at three different land use type viz., enset-coffee, crop land, and grazing land. There was water soluble, ammonium acetate, nitric acid extractable potassium, exchangeable potassium, and non-exchangeable potassium studied in soil samples, which were collected from 0-20 cm depth of each land type. The study revealed that water soluble and ammonium acetate extractable potassium concentrations ranged from 0.04 to 0.42 cmolKg-1 soils enset-coffee and grazing land use types, respectively. The study showed that exchangeable potassium constituted the highest proportion of available potassium, while the proportion of water soluble potassium was found to be the lowest. In this study, non-exchangeable potassium concentrations varied from 0.10 to 0.04cmolKg-1soils for enset-coffee, and crop and grazing land use type. Furthermore, available potassium and exchangeable potassium concentrations were positively correlated with OC(r=0.95***), cation exchange capacity, and sand and clay(r=0.98***). In addition, the K dynamics as impacted by land use types found that the highest change in exchangeable potassium (0.31cmolkg-1soils) and potential buffering capacity (1.79cmolkg-1soils) were noted in crop land use types, whereas the lowest change(1.26cmolkg-1 soils) was observed in the enset-coffee system, The varying properties, potassium status, dynamic and land use type of soils identified in the study areas provided adequate information to design soil potassium management options and further research about the soil in each site. Therefore, application of site specific soil fertility management practices and research can improve soil potassium status and quantity intensity parameters to sustain crop productive soils.


2017 ◽  
Vol 8 (1) ◽  
pp. 91-111 ◽  
Author(s):  
Anita D. Bayer ◽  
Mats Lindeskog ◽  
Thomas A. M. Pugh ◽  
Peter M. Anthoni ◽  
Richard Fuchs ◽  
...  

Abstract. Land-use and land-cover (LUC) changes are a key uncertainty when attributing changes in measured atmospheric CO2 concentration to its sinks and sources and must also be much better understood to determine the possibilities for land-based climate change mitigation, especially in the light of human demand on other land-based resources. On the spatial scale typically used in terrestrial ecosystem models (0.5 or 1°) changes in LUC over time periods of a few years or more can include bidirectional changes on the sub-grid level, such as the parallel expansion and abandonment of agricultural land (e.g. in shifting cultivation) or cropland–grassland conversion (and vice versa). These complex changes between classes within a grid cell have often been neglected in previous studies, and only net changes of land between natural vegetation cover, cropland and pastures accounted for, mainly because of a lack of reliable high-resolution historical information on gross land transitions, in combination with technical limitations within the models themselves. In the present study we applied a state-of-the-art dynamic global vegetation model with a detailed representation of croplands and carbon–nitrogen dynamics to quantify the uncertainty in terrestrial ecosystem carbon stocks and fluxes arising from the choice between net and gross representations of LUC. We used three frequently applied global, one recent global and one recent European LUC datasets, two of which resolve gross land transitions, either in Europe or in certain tropical regions. When considering only net changes, land-use-transition uncertainties (expressed as 1 standard deviation around decadal means of four models) in global carbon emissions from LUC (ELUC) are ±0.19, ±0.66 and ±0.47 Pg C a−1 in the 1980s, 1990s and 2000s, respectively, or between 14 and 39 % of mean ELUC. Carbon stocks at the end of the 20th century vary by ±11 Pg C for vegetation and ±37 Pg C for soil C due to the choice of LUC reconstruction, i.e. around 3 % of the respective C pools. Accounting for sub-grid (gross) land conversions significantly increased the effect of LUC on global and European carbon stocks and fluxes, most noticeably enhancing global cumulative ELUC by 33 Pg C (1750–2014) and entailing a significant reduction in carbon stored in vegetation, although the effect on soil C stocks was limited. Simulations demonstrated that assessments of historical carbon stocks and fluxes are highly uncertain due to the choice of LUC reconstruction and that the consideration of different contrasting LUC reconstructions is needed to account for this uncertainty. The analysis of gross, in addition to net, land-use changes showed that the full complexity of gross land-use changes is required in order to accurately predict the magnitude of LUC change emissions. This introduces technical challenges to process-based models and relies on extensive information regarding historical land-use transitions.


RSC Advances ◽  
2018 ◽  
Vol 8 (57) ◽  
pp. 32588-32596 ◽  
Author(s):  
Beidou Xi ◽  
Zhurui Tang ◽  
Jie Jiang ◽  
Wenbing Tan ◽  
Caihong Huang ◽  
...  

Agricultural land-use types could affect the transformation and decomposition of HS in soils, and thus further change the intrinsic chemical structures associated with ETC.


BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yeneayehu Fenetahun ◽  
Wang Yong-dong ◽  
Yuan You ◽  
Xu Xinwen

Abstract Background The gradual conversion of rangelands into other land use types is one of the main challenges affecting the sustainable management of rangelands in Teltele. This study aimed to examine the changes, drivers, trends in land use and land cover (LULC), to determine the link between the Normalized Difference Vegetation Index (NDVI) and forage biomass and the associated impacts of forage biomass production dynamics on the Teltele rangelands in Southern Ethiopia. A Combination of remote sensing data, field interviews, discussion and observations data were used to examine the dynamics of LULC between 1992 and 2019 and forage biomass production. Results The result indicate that there is a marked increase in farm land (35.3%), bare land (13.8%) and shrub land (4.8%), while the reduction found in grass land (54.5%), wet land (69.3%) and forest land (10.5%). The larger change in land observed in both grassland and wetland part was observed during the period from 1995–2000 and 2015–2019, this is due to climate change impact (El-Niño) happened in Teltele rangeland during the year 1999 and 2016 respectively. The quantity of forage in different land use/cover types, grass land had the highest average amount of forage biomass of 2092.3 kg/ha, followed by wetland with 1231 kg/ha, forest land with 1191.3 kg/ha, shrub land with 180 kg/ha, agricultural land with 139.5 kg/ha and bare land with 58.1 kg/ha. Conclusions The significant linkage observed between NDVI and LULC change types (when a high NDVI value, the LULC changes also shows positive value or an increasing trend). In addition, NDVI value directly related to the greenness status of vegetation occurred on each LULC change types and its value directly linkage forage biomass production pattern with grassland land use types. 64.8% (grass land), 43.3% (agricultural land), 75.1% (forest land), 50.6% (shrub land), 80.5% (bare land) and 75.5% (wet land) more or higher dry biomass production in the wet season compared to the dry season.


2020 ◽  
Vol 66 (3) ◽  
pp. 382-391 ◽  
Author(s):  
Xu-dong Huang ◽  
Dong Wang ◽  
Pei-pei Han ◽  
Wen-chuan Wang ◽  
Qing-jie Li ◽  
...  

Abstract Understanding the relation between land-use types and baseflow mean response time (BMRT) is important to explore the response mechanism of baseflow processes in watersheds. BMRT was determined using an instantaneous unit hydrograph. The instantaneous unit hydrograph parameters were estimated by autocorrelation functions. The relative importance of land-use types in determining BMRT dynamics was assessed by hydrological model and partial least-squares regression. Our study suggests greater effects of urban area on BMRT than the effects of forest and agricultural land. This may be because the urban interception impervious area may impede baseflow generation over a short timescale. The effects of agricultural land are greater than those of forest in areas with steeper hillslopes, but lower than those of the forest in areas with more plains, reflecting the varied ability of forest and agricultural lands with different topography to hinder overland flow. Variations of BMRT are strongly linked to land use in the watershed. Overall, our study provides insight into the BMRT and dominant factors of land-use types in watersheds, planning of sustainable water resource use, and ecological protection in watersheds.


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