scholarly journals Towards ecologically functional riparian zones: A meta-analysis to develop guidelines for protecting ecosystem functions and biodiversity in agricultural landscapes

2019 ◽  
Vol 249 ◽  
pp. 109391 ◽  
Author(s):  
Lovisa Lind ◽  
Eliza Maher Hasselquist ◽  
Hjalmar Laudon
Keyword(s):  
Meta Analysis ◽  
Agricultural Landscapes ◽  
Ecosystem Functions ◽  
Riparian Zones

scholarly journals Improved Accuracy of Riparian Zone Mapping Using Near Ground Unmanned Aerial Vehicle and Photogrammetry Method

2021 ◽  
Vol 13 (10) ◽  
pp. 1997
Author(s):  
Joan Grau ◽  
Kang Liang ◽  
Jae Ogilvie ◽  
Paul Arp ◽  
Sheng Li ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Precision Agriculture ◽  
Riparian Zone ◽  
Agricultural Landscapes ◽  
Agricultural Watershed ◽  
Riparian Zones ◽  
Surface Model ◽  
Low Resolution ◽  
Channel Network ◽  
Aerial Vehicle

In agriculture-dominant watersheds, riparian ecosystems provide a wide array of benefits such as reducing soil erosion, filtering chemical compounds, and retaining sediments. Traditionally, the boundaries of riparian zones could be estimated from Digital Elevation Models (DEMs) or field surveys. In this study, we used an Unmanned Aerial Vehicle (UAV) and photogrammetry method to map the boundaries of riparian zones. We first obtained the 3D digital surface model with a UAV. We applied the Vertical Distance to Channel Network (VDTCN) as a classifier to delineate the boundaries of the riparian area in an agricultural watershed. The same method was also used with a low-resolution DEM obtained with traditional photogrammetry and two more LiDAR-derived DEMs, and the results of different methods were compared. Results indicated that higher resolution UAV-derived DEM achieved a high agreement with the field-measured riparian zone. The accuracy achieved (Kappa Coefficient, KC = 63%) with the UAV-derived DEM was comparable with high-resolution LiDAR-derived DEMs and significantly higher than the prediction accuracy based on traditional low-resolution DEMs obtained with high altitude aerial photos (KC = 25%). We also found that the presence of a dense herbaceous layer on the ground could cause errors in riparian zone delineation with VDTCN for both low altitude UAV and LiDAR data. Nevertheless, the study indicated that using the VDTCN as a classifier combined with a UAV-derived DEM is a suitable approach for mapping riparian zones and can be used for precision agriculture and environmental protection over agricultural landscapes.

Nitrogen retention effect of riparian zones in agricultural areas: A meta-analysis

2021 ◽  
pp. 128143
Author(s):  
Chunjian Lyu ◽  
Xiaojie Li ◽  
Peng Yuan ◽  
Yonghui Song ◽  
Hongjie Gao ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Nitrogen Retention ◽  
Riparian Zones ◽  
Agricultural Areas

scholarly journals A global meta-analysis shows soil nitrogen pool increases after revegetation of riparian zones

2021 ◽  
Author(s):  
Negar Omidvar ◽  
Zhihong Xu ◽  
Thi Thu Nhan Nguyen ◽  
Babak Salehin ◽  
Steven Ogbourne ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
Meta Analysis ◽  
Riparian Zones ◽  
Nitrogen Pool

Modelling impacts of climate change and alternative management interventions on the multi-functionality of agricultural landscapes in southern Africa

2020 ◽  
Author(s):  
Reimund Roetter ◽  
Simon Scheiter ◽  
Munir Hoffmann ◽  
Kwabena Ayisi ◽  
Paolo Merante ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Agricultural Landscapes ◽  
Sub Saharan Africa ◽  
Ecosystem Functions ◽  
Drought Risk ◽  
Crop Models ◽  
Landscape Level

<p><span><span>On the background of increasing welfare and continued population growth, there is an ever-increasing pressure on land and other natural resources in many parts of the world. The situation is, however, particularly severe in the drylands of Sub-Saharan Africa. Southern African landscapes, composed of arable lands, tree orchards and rangelands, provide a range of important ecosystem functions. These functions are increasingly threatened by land use changes through competing claims on land by agriculture, tourism, mining and other sectors, and by environmental change, namely climate change and soil degradation. Among others, climate models project that drought risk in the region will increase considerably. Based on comprehensive data sets originating from previous groundwork by several collaborative projects on the functioning of these ecosystems, a number of biophysical and bio-economic models have been developed and evaluated. In the framework of the South African Limpopo Landscapes network (SALLnet) we have now refined and tailored these models for combined use for the assessment of changes in multiple functions of the prevailing agroecosystems when affected by alternative climate and land management scenarios - from field to regional scale. We apply vegetation models (such as aDGVM), crop models (such as APSIM) and integrative farm level models (e.g. agent-based) for different farming systems in conjunction with geo-referenced databases. Model outputs are combined to assess the impact of management x environment interactions on various ecosystem functions. Of special interest in our study are the ecosystem services related to the provision of food, feed and fuel, soil and water conservation, as well as recycling and restoring carbon and nutrients in soil. To illustrate how the combination of various modelling components can work in assessing management intervention effects under different environmental conditions on landscape level ecosystem services, a case study was defined in Limpopo province, South Africa. We investigated effects of current management practices and an intensification scenario over a longer period of years on soil organic carbon change under rangeland and arable land, potential erosion, productive water use, biomass production, monthly feed gaps, and rangeland habitat quality. Tentative results showed that sustainable intensification closed the livestock feed gap, but further reduced soil organic carbon. More generally, coupling the output of vegetation and crop models regionally calibrated with sound ground/ experimental data appears promising to provide meaningful insights into the highly complex interconnections of different ecosystem services at a landscape level.</span></span></p>

scholarly journals Environmental variation and its effect on the success of crop-wild hybridization in the Raphanus species complex

2021 ◽  
Author(s):  
Kruti Shukla
Keyword(s):  
Soil Moisture ◽  
Meta Analysis ◽  
Common Garden ◽  
Environmental Variation ◽  
Agricultural Landscapes ◽  
Evolutionary Trajectory ◽  
High Soil Moisture ◽  
Wild Hybrid ◽  
New Perspective ◽  
Advanced Generation

Hybridization has been suggested as mechanism that can contribute to adaptive evolution and the success of crop-wild hybrid populations; but this response appears to depend upon environmental context. I explore how environmental variation affects crop trait expression, the strength and direction of selection on crop traits in radish weed populations, and the influence environmental variation has on crop-trait introgression across agricultural landscapes. Using the Raphanus crop-wild complex as a model system to study the environmental sensitivity of crop gene flow into weed populations, I first planted advanced-generation wild and crop-wild hybrid radish plants (that had previously evolved for three generations under relatively dry, relatively wet, or ambient control soil moisture or water-evolved conditions) into sheltered common gardens that were watered with low, ambient, or high soil moisture. From this work, hybridization and watering history did not enhance the success of advanced-generation hybrid plants relative to wild progenitors in Ontario, Canada. Next, I explored how phenotypic plasticity in response to environmental variation may distort a commonly used metric to measure the rate of evolution, the haldane. To determine the extent that plasticity affected estimates of evolutionary rate, I compared haldane estimates of advanced-generation water-evolved plants grown in a common garden that did not involve manipulation of ambient watering conditions. Estimates of the magnitude and direction of contemporary evolution differed significantly due to annual environmental variation, particularly for wild populations. Thus, I propose changes to the use of these equations and changes to the equation itself to help avoid generating false estimates of evolutionary rates. Finally, a meta-analysis of radish phenology and fecundity data collected from the last twelve years across four locations revealed that geography can affect the strength and direction of selection on crop- derived traits in weedy radish populations. This large, integrated study offers environmental risk assessment a new perspective on the role of environmental change on the success of crop-wild hybridization and its ability to generate weedy species. In summary, I provide evidence that environmental variation should be considered before making predictions about a crop trait’s evolutionary trajectory and persistence in a weedy plant population.

scholarly journals Temporal and microtopographical variations in greenhouse gas fluxes from riparian forest soils along headwater streams

2021 ◽  
Author(s):  
Teresa K. Silverthorn ◽  
John S. Richardson
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Greenhouse Gas ◽  
Riparian Zone ◽  
Headwater Streams ◽  
Riparian Forest ◽  
Ecosystem Functions ◽  
Riparian Zones ◽  
Gas Fluxes ◽  
Ghg Fluxes

Abstract Riparian zones of headwater streams have valuable ecosystem functions and are prevalent across many landscapes. Nevertheless, studies of greenhouse gas (GHG; CO 2 , CH 4 , N 2 O) fluxes from these unique ecosystems, with fluctuating water tables and high soil organic matter, remain limited. Our objectives were to (1) to quantify the effects of local riparian groundwater conditions on soil GHG flux rates, namely to determine if groundwater discharge (DIS) areas in the riparian zone would have higher soil moisture than adjacent non-discharge (ND) areas in the riparian zone, impacting GHG fluxes; and (2) to examine the relationship between GHG fluxes, soil moisture, soil temperature, and groundwater depth. We measured gas fluxes in situ alongside two relatively undisturbed headwater streams over one year, using closed static chambers and gas chromatography. We found that, although not significant, DIS areas had on average lower CH 4 uptake and lower CO 2 emissions than ND areas. We further found that soil temperature explained 30.0% and 26.2% of variation in CO 2 and N 2 O fluxes, respectively, and soil moisture explained 9.8% of variation in CH 4 fluxes. Our results provide information on the magnitude and drivers of GHG fluxes in riparian zones to help inform GHG budgets and forest management.

scholarly journals Egestion Versus Excretion: A Meta-Analysis Examining Nutrient Release Rates and Ratios across Freshwater Fauna

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 189
Author(s):  
Halvor M. Halvorson ◽  
Carla L. Atkinson
Keyword(s):  
Animal Species ◽  
Meta Analysis ◽  
Nutrient Release ◽  
Nutrient Flux ◽  
Ecosystem Functions ◽  
Dissolved Nutrients ◽  
Total N ◽  
Quantitative Evidence ◽  
Excretion Rates

In aquatic settings, animals directly affect ecosystem functions through excretion of dissolved nutrients. However, the comparative role of egestion as an animal-mediated nutrient flux remains understudied. We conducted a literature survey and meta-analysis to directly compare nitrogen (N), phosphorus (P), and N:P of egestion compared to excretion rates and ratios across freshwater animals. Synthesizing 215 datasets across 47 animal species (all primary consumers or omnivores), we show that the total N and P egestion rates exceed inorganic N and P excretion rates but not total N and P excretion rates, and that proportions of P egested compared to excreted depend on body size and animal phylum. We further show that variance of egestion rates is often greater than excretion rates, reflecting greater inter-individual and temporal variation of egestion as a nutrient flux in comparison to excretion. At phylogenetic levels, our analysis suggests that Mollusca exhibit the greatest rates and variance of P egestion relative to excretion, especially compared to Arthropoda. Given quantitative evidence of egestion as a dominant and dynamic animal-mediated nutrient flux, our synthesis demonstrates the need for additional studies of rates, stoichiometry, and roles of animal egestion in aquatic settings.

Organic carbon storage in the biomass and soils of hedgerows

2020 ◽  
Author(s):  
Sophie Drexler ◽  
Axel Don
Keyword(s):  
Organic Carbon ◽  
Carbon Storage ◽  
Carbon Stock ◽  
Meta Analysis ◽  
Agricultural Landscapes ◽  
Soil Protection ◽  
Biomass Carbon ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Below Ground

<p>The establishment of hedgerows as traditional form of agroforestry in Europe is a promising strategy to promote carbon sinks in the context of climate change mitigation. However, only few studies quantified the potential of hedgerows to sequester and store carbon. We therefore conducted a meta-analysis to gain a quantitative overview about the carbon storage in the above- and below-ground biomass and soils of hedgerows.</p><p>Soil organic carbon (SOC) data of hedgerows and adjacent agricultural fields of nine studies with 83 hedgerow sites was compiled. On average, the establishment of hedgerows on cropland increased SOC by 32%. No significant differences were found between the SOC storage of hedgerows and that of grassland. The literature survey on the biomass carbon stocks of hedgerows resulted in 23 sampled hedgerows, which were supplemented by own biomass data of 49 hedgerows from northern Germany. Biomass stocks increased with time since last coppicing and hedgerow height. The mean (± SD) above-ground biomass carbon stock of the analysed hedgerows was 48 ± 29 Mg C ha<sup>-1</sup>. Below-ground biomass values seemed mostly underestimated, as they were calculated from above-ground biomass via fixed assumed root:shoot ratios not specific for hedgerows. Only one study reported measured root biomass under hedgerows with a root:shoot ratio of 0.94:1 ± 0.084. With this shoot:root ratio an average below-ground biomass carbon stock of 45 ± 28 Mg C ha<sup>-1 </sup>was estimated, but with high uncertainty.</p><p>Thus, the establishment of hedgerows on cropland could lead to a SOC sequestration of 1.0 Mg C ha<sup>-1</sup> year<sup>-1</sup> over a 20-year period. Additionally, up to 9.4 Mg C ha<sup>-1</sup> year<sup>-1</sup> could be sequestered in the hedgerow biomass over a 10 year period. In total, hedgerows store 106 ± 41 Mg C ha<sup>-1</sup> more C than croplands. Our results indicate that organic carbon stored in hedgerows is similar high as in forests. We discuss how the establishment of hedgerows, especially on cropland, can thus be an effective option for C sequestration in agricultural landscapes, meanwhile enhance biodiversity, and soil protection.</p>

scholarly journals Landscape and microhabitat features determine small mammal abundance in forest patches in agricultural landscapes

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12306
Author(s):  
Luca Dorigo ◽  
Francesco Boscutti ◽  
Maurizia Sigura
Keyword(s):  
Small Mammals ◽  
Agricultural Landscape ◽  
Species Abundance ◽  
Strong Relationship ◽  
Species Interaction ◽  
Agricultural Landscapes ◽  
Ecosystem Functions ◽  
Forest Patch ◽  
Generalist Species ◽  
Ecological Requirements

Intensification of agricultural landscapes represent a major threat for biodiversity conservation also affecting several ecosystem services. The natural and semi-natural remnants, available in the agricultural matrix, represent important sites for small mammals and rodents, which are fundamental for sustaining various ecosystem functions and trophic chains. We studied the populations of two small mammals (Apodemus agrarius, A. sylvaticus) to evaluate the effects of landscape and habitat features on species abundance along a gradient of agricultural landscape intensification. The study was performed in Friuli Venezia Giulia (north-eastern Italy) during 19 months, in 19 wood remnants. Species abundance was determined using Capture-Mark-Recapture (CMR) techniques. In the same plots, main ecological parameters of the habitat (at microhabitat and patch scale) and landscape were considered. Abundance of A. agrarius increased in landscapes with high extent of permanent crops (i.e., orchards and poplar plantations) and low content of undecomposed litter in the wood understory. Instead, A. sylvaticus, a more generalist species, showed an opposite, albeit less strong, relationship with the same variables. Both species were not affected by any landscape structural feature (e.g., patch shape, isolation). Our findings showed that microhabitat features and landscape composition rather than wood and landscape structure affect populations’ abundance and species interaction. The opposite response of the two study species was probably because of their specific ecological requirements. In this light, conservation management of agricultural landscapes should consider the ecological needs of species at both landscape and habitat levels, by rebalancing composition patterns in the context of ecological intensification, and promoting a sustainable forest patch management.

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