scholarly journals Identification of typical eco-hydrological behaviours using InSAR allows landscape-scale mapping of peatland condition

2021 ◽  
Author(s):  
Andrew Vincent Bradley ◽  
Roxane Andersen ◽  
Chris Marshall ◽  
Andrew Sowter ◽  
David James Large
Keyword(s):  
Bimodal Distribution ◽  
Global Scale ◽  
Landscape Scale ◽  
Gas Content ◽  
Surface Motion ◽  
Vegetation Communities ◽  
Peatland Restoration ◽  
Blanket Bog ◽  
Satellite Radar ◽  
Topographic Gradients

Abstract. Better tools for rapid and reliable assessment of global peatland extent and condition are urgently needed to support action to prevent their further decline. Peatland surface motion is a response to changes in the water and gas content of a peat body regulated by the ecology and hydrology of a peatland system. Surface motion is therefore a sensitive measure of ecohydrological condition but has traditionally been impossible to measure at the landscape scale. Here we examine the potential of surface motion metrics derived from InSAR satellite radar to map peatland condition in a blanket bog landscape. We show that the timing of maximum seasonal swelling of the peat is characterized by a bimodal distribution. The first maximum is typical of steeper topographic gradients, peatland margins, degraded peatland and more often associated with ‘shrub’-dominated vegetation communities. The second maximum is typically associated with low topographic gradients often featuring pool systems, and Sphagnum dominated vegetation communities. Specific conditions associated with ‘Sphagnum’ and ‘shrub’ communities are also determined by the amplitude of swelling and average multiannual motion. Peatland restoration currently follows a re-wetting strategy, however our approach highlights that landscape setting appears to determine the optimal endpoint for restoration. Aligning expectation for restoration outcomes with landscape setting might optimise peatland stability and carbon storage. Importantly, deployment of this approach, based on surface motion dynamics, could support peatland mapping and management on a global scale.

scholarly journals Catchment water quality in the year preceding and immediately following restoration of a drained afforested blanket bog

2021 ◽  
Author(s):  
Paul P. J. Gaffney ◽  
Mark H. Hancock ◽  
Mark A. Taggart ◽  
Roxane Andersen
Keyword(s):  
Water Quality ◽  
Nutrient Release ◽  
Pass Rate ◽  
Future Research ◽  
Negative Effects ◽  
Short Term ◽  
Peatland Restoration ◽  
Blanket Bog ◽  
Quality Threshold ◽  
Policy Incentives

AbstractThe restoration of drained afforested peatlands, through drain blocking and tree removal, is increasing in response to peatland restoration targets and policy incentives. In the short term, these intensive restoration operations may affect receiving watercourses and the biota that depend upon them. This study assessed the immediate effect of ‘forest-to-bog’ restoration by measuring stream and river water quality for a 15 month period pre- and post-restoration, in the Flow Country peatlands of northern Scotland. We found that the chemistry of streams draining restoration areas differed from that of control streams following restoration, with phosphate concentrations significantly higher (1.7–6.2 fold, mean 4.4) in restoration streams compared to the pre-restoration period. This led to a decrease in the pass rate (from 100 to 75%) for the target “good” quality threshold (based on EU Water Framework Directive guidelines) in rivers in this immediate post-restoration period, when compared to unaffected river baseline sites (which fell from 100 to 90% post-restoration). While overall increases in turbidity, dissolved organic carbon, iron, potassium and manganese were not significant post-restoration, they exhibited an exaggerated seasonal cycle, peaking in summer months in restoration streams. We attribute these relatively limited, minor short-term impacts to the fact that relatively small percentages of the catchment area (3–23%), in our study catchments were felled, and that drain blocking and silt traps, put in place as part of restoration management, were likely effective in mitigating negative effects. Looking ahead, we suggest that future research should investigate longer term water quality effects and compare different ways of potentially controlling nutrient release.

scholarly journals Global-scale drivers of crop visitor diversity and the historical development of agriculture

2019 ◽  
Vol 286 (1915) ◽  
pp. 20192096 ◽  
Author(s):  
Julian Brown ◽  
Saul A. Cunningham
Keyword(s):  
Evolutionary History ◽  
Habitat Management ◽  
Spatial Scales ◽  
Global Scale ◽  
Landscape Scale ◽  
Region Of Origin ◽  
Flower Visitor ◽  
History Of ◽  
Bee Diversity ◽  
Analyse Data

Understanding diversity in flower-visitor assemblages helps us improve pollination of crops and support better biodiversity conservation outcomes. Much recent research has focused on drivers of crop-visitor diversity operating over spatial scales from fields to landscapes, such as pesticide and habitat management, while drivers operating over larger scales of continents and biogeographic realms are virtually unknown. Flower and visitor traits influence attraction of pollinators to flowers, and evolve in the context of associations that can be ancient or recent. Plants that have been adopted into agriculture have been moved widely around the world and thereby exposed to new flower visitors. Remarkably little is known of the consequence of these historical patterns for present-day crop-visiting bee diversity. We analyse data from 317 studies of 27 crops worldwide and find that crops are visited by fewer bee genera outside their region of origin and outside their family's region of origin. Thus, recent human history and the deeper evolutionary history of crops and bees appear to be important determinants of flower-visitor diversity at large scales that constrain the levels of visitor diversity that can be influenced by field- and landscape-scale interventions.

Peatland restoration age (Scotland, UK) can be better reproduced by a classification model based on Sentinel-2 than with high resolution aerial imagery

2020 ◽  
Author(s):  
Rebekka Artz ◽  
Jonathan Ball ◽  
Catherine Smart ◽  
Gillian Donaldson-Selby ◽  
Neil Cowie ◽  
...  
Keyword(s):  
Landscape Scale ◽  
Aerial Imagery ◽  
Classification Model ◽  
Vegetation Composition ◽  
National Scale ◽  
Model Uncertainties ◽  
Peatland Restoration ◽  
Natural Climate ◽  
Main Model ◽  
Sentinel 2

<p>Damage to peatland globally causes significant contributions to the current net greenhouse gas emissions and pose a further future risk as such damaged peatlands are vulnerable to future climatic stress. Globally, peatland restoration efforts are rapidly increasing in scale as natural climate solutions, yet relatively little effort has been it into effective monitoring of landscape scale restoration projects. We developed a classification model that uses remote observations (Sentinel-2 or national scale aerial imagery from Getmapping) to detect restoration efficacy by training it against a dataset from a chronosequence of spatially collocated peatland restoration sites that had previously been converted to plantation forestry. The Sentinel-2 based model greatly outperformed the aerial imagery-based model (RGB and IR, 25 and 50 cm, respectively). Adding slope to the classification improved kappa by less than 0.02. Prediction of the starting (forestry) and target (restored) state was very robust, and both recent and the oldest restoration sites were spatially well predicted. The main model uncertainties lie with sites of intermediate age, where on-the-ground restoration trajectories based on vegetation composition also differ the most, and with sites where additional layers of management after the initial restoration management have been applied.</p>

New insights on controls of piping distribution in degraded blanket bog

2020 ◽  
Author(s):  
Taco Regensburg ◽  
Joseph Holden ◽  
Pippa Chapman ◽  
Michael Pilkington ◽  
Martin Evans
Keyword(s):  
Experimental Design ◽  
Control Treatment ◽  
Slope Aspect ◽  
Natural Soil ◽  
Porous System ◽  
Initial Field ◽  
Peatland Restoration ◽  
Blanket Bog ◽  
Restoration Work ◽  
Pipe Outlet

<p>As part of the EU-funded MoorLIFE2020 project, which examines strategies to restore degraded blanket bog in the Peak District of northern England, we investigated natural soil pipes. These pipes are a cause of concern to peatland restoration practitioners who are unsure whether to block them to reduce erosion and flood risk when conducting restoration work. Soil pipes often occur in complex networks with varying channel sizes, undulating through the soil profile. Their prevalence is often linked to controls such as topographic location, slope, aspect, vegetation cover, climate, and properties of the surrounding soil. Such relationships are poorly understood for degraded blanket bog. A before-after-control treatment study was designed to examine the effects of pipe blocking on fluvial carbon removal and streamflow in Upper North Grain (UNG), a small headwater catchment located between 490 m and 541 m above sea level. The catchment has a blanket peat cover up to four meters thick at places, with a branching network of deep gullies that incise into the bedrock. This experimental design was envisaged to address the following hypotheses: (i) the severity of degradation of UNG is a dominant control on pipe density; (ii) blocking of pipe outlets impairs pipe-to-stream connectivity. Our results point towards a rejection of both hypotheses. An initial field survey used to locate and characterize pipe outlets, resulted in 353 individual outlet recordings with a density of 13.79 per km of surveyed gully bank. Southeast, south, southwest and west-facing gully banks accounted for more than 75% of identified pipe outlets. The experimental design compares water and aquatic carbon fluxes in two streams - in one catchment the active pipe outlets (n=25) were blocked by closing off the void behind the pipe outlet with peat and stones, wooden screens or plastic pilling, while in the other catchment the pipes were left open. Areas on the gully bank around original outlets were photographed every two weeks. This analysis showed that within the first month after blocking, all treated pipes had formed bypass routes around the block and initiated new pipe outlets. New outlets were found both above and below the original pipe outlet at distances up to 1 meter from the original pipe outlet regardless of bank aspect, suggesting the networks behind a pipe outlet to be a porous system that connects in both vertical and horizontal directions when issuing onto gully banks. Further results will be presented from the ongoing monitoring showing effects of pipe blocking on streamflow storm responses and the export of particulate and dissolved organic carbon from pipes and streams.</p>

scholarly journals GPM Satellite Radar Observations of Precipitation Mechanisms in Atmospheric Rivers

2020 ◽  
Vol 148 (4) ◽  
pp. 1449-1463 ◽  
Author(s):  
Forest Cannon ◽  
Jason M. Cordeira ◽  
Chad W. Hecht ◽  
Joel R. Norris ◽  
Allison Michaelis ◽  
...  
Keyword(s):  
Water Cycle ◽  
Global Scale ◽  
Convective Precipitation ◽  
Dual Frequency ◽  
Atmospheric Rivers ◽  
Precipitation Measurement ◽  
Precipitation Processes ◽  
Thermodynamic Conditions ◽  
Satellite Radar ◽  
Global Precipitation

Abstract Despite numerous studies documenting the importance of atmospheric rivers (AR) to the global water cycle and regional precipitation, the evolution of their water vapor fluxes has been difficult to investigate given the challenges of observing and modeling precipitation processes within ARs over the ocean. This study uses satellite-based radar reflectivity profiles from the Global Precipitation Measurement Dual-Frequency Precipitation Radar (GPM-DPR), combined with kinematic and thermodynamic conditions in the vicinity of the precipitation diagnosed from the Climate Forecast System Reanalysis, to evaluate the characteristics and dynamical origins of precipitation in ARs over the northeast Pacific Ocean. Transects of 192 ARs between 2014 and 2018 are examined. Both stratiform and convective precipitation were abundant in these GPM transects and the precipitation was most often generated by forced ascent in the vicinity of a cold front in frontogenetic environments. Conditioning composite vertical profiles of reflectivity and latent heating from GPM-DPR on frontogenesis near the moist-neutral low-level jet demonstrated the importance of frontally forced precipitation on atmospheric heating tendencies. A case study of a high-impact landfalling AR is analyzed using the Weather Research and Forecasting Model, which showed how the precipitation processes and subsequent latent heat release offshore strongly influenced AR evolution. Although these precipitation mechanisms are present in global-scale models, the difficulty that coarse-resolution models have in accurately representing resultant precipitation likely translates to uncertainty in forecasting heating tendencies, their feedbacks on AR evolution, and ultimately the impacts of ARs upon landfall in the western United States.

scholarly journals InSAR Time Series Analysis of L-Band Data for Understanding Tropical Peatland Degradation and Restoration

2019 ◽  
Vol 11 (21) ◽  
pp. 2592
Author(s):  
Zhiwei Zhou ◽  
Zhenhong Li ◽  
Susan Waldron ◽  
Akiko Tanaka
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Ground Surface ◽  
Relative Magnitude ◽  
Construction Time ◽  
Series Analysis ◽  
Peatland Restoration ◽  
L Band ◽  
Satellite Radar ◽  
Peatland Degradation

In this study, satellite radar observations are employed to reveal spatiotemporal changes in ground surface height of peatlands that have, and have not, undergone restoration in Central Kalimantan, Indonesia. Our time series analysis of 26 scenes of Advanced Land Observation Satellite-1 (ALOS-1) Phased-Array L-band Synthetic-Aperture Radar (PALSAR) images acquired between 2006 and 2010 suggests that peatland restoration was positively affected by the construction time of dams—the earlier the dam was constructed, the more significant the restoration appears. The results also suggest that the dams resulted in an increase of ground water level, which in turn stopped peat losing height. For peatland areas without restoration, the peatland continuously lost peat height by up to 7.7 cm/yr. InSAR-derived peat height changes allow the investigation of restoration effects over a wide area and can also be used to indirectly assess the relative magnitude and spatial pattern of peatland damage caused by drainage and fires. Such an assessment can provide key information for guiding future restoration activities.

Soil disturbance by animals at varying spatial scales in a semi-arid Australian woodland

2008 ◽  
Vol 30 (3) ◽  
pp. 327 ◽  
Author(s):  
David J. Eldridge ◽  
Alan B. C. Kwok
Keyword(s):  
Total Mass ◽  
Spatial Scales ◽  
Soil Disturbance ◽  
Landscape Scale ◽  
Small Scale ◽  
Vegetation Communities ◽  
Resting Sites ◽  
Animal Activity ◽  
Open Woodland ◽  
Semi Arid

We studied soil disturbance by rabbits, echidnas, goannas, ants and termites at three different spatial scales across four vegetation communities (dense woodland, open woodland, shrubland, grassland) in semi-arid rangeland in western NSW. For analyses, bare and litter-covered surfaces (micro-scale) were nested within canopy and open patches (intermediate scale), which were nested within vegetation communities (landscape scale). Landscape-scale disturbances (rabbit warrens) were six and three times more abundant in open woodlands and shrublands, respectively, than in dense woodlands. Although individual warrens had a similar mass of excavated soil across all vegetation communities, in total, more soil was excavated in the grasslands than in the dense woodlands or shrublands. There were four times as many intermediate-sized disturbances (foraging pits and resting sites) under canopies than out in the open, and this was consistent across all vegetation communities. Echidna foraging pits and kangaroo resting sites dominated the canopy patches. Intermediate-sized disturbances scaled up to the landscape scale were marginally more abundant in the dense and open woodlands than in grasslands and shrublands. However, total mass of soil moved by all species did not differ among vegetation communities. The density of small-scale disturbances (ant nests, termite foraging galleries) did not differ at the landscape-, intermediate- or micro-scales. Our study documents the extent of animal activity in the semi-arid woodlands, and reinforces the notion that, as soil disturbance is scale-dependent, differences among species, habitats and communities will depend on the scale at which disturbances are examined.

scholarly journals Paleolatitudinal distribution of lithologic indicators of climate in a paleogeographic framework

2017 ◽  
Author(s):  
Wenchao Cao ◽  
Simon Williams ◽  
Nicolas Flament ◽  
Sabin Zahirovic ◽  
Christopher Scotese ◽  
...  
Keyword(s):  
Early Carboniferous ◽  
Bimodal Distribution ◽  
Global Scale ◽  
Plate Motion ◽  
Oceanic Circulation ◽  
Geological Time ◽  
Deep Time ◽  
Plate Reconstructions ◽  
Continental Area ◽  
Poleward Shift

Whether the latitudinal distribution of climate-sensitive lithologies are stable through greenhouse and icehouse regimes remains unclear. Previous studies suggest that the paleolatitudinal distribution of paleoclimate indicators, including coals, evaporites, reefs and carbonates, have remained broadly similar since Permian times, leading to the conclusion that atmospheric and oceanic circulation control their distribution rather than the latitudinal temperature gradient. Here we revisit a global-scale compilation of lithologic indicators of climate, including coals, evaporites and glacial deposits, back to the Devonian period. We test the sensitivity of their latitudinal distributions to the uneven distribution of continental areas through time and to global tectonic models, correct the latitudinal distributions of lithologies for sampling- and continental area-bias, and use statistical methods to fit these distributions with probability density functions and estimate their high-density latitudinal ranges with 50% and 95% confidence intervals. The results suggest that the paleolatitudinal distributions of lithologies have changed through deep geological time, notably a pronounced poleward shift in the distribution of coals at the beginning of the Permian. The distribution of evaporites indicate a clearly bimodal distribution over the past ~400 Ma, except for Early Devonian, Early Carboniferous (Serpukhovian), the earliest Permian (Asselian-Sakmarian) and Middle and Late Jurassic times. We discuss how the patterns indicated from these lithologies change through time in response to plate motion, orography, evolution, and greenhouse/icehouse conditions. This study highlights that plate reconstructions, combined with a comprehensive lithologic database, and novel data analysis provide insights on the shifting climatic zones through deep time.

scholarly journals Palaeolatitudinal distribution of lithologic indicators of climate in a palaeogeographic framework

2018 ◽  
Vol 156 (2) ◽  
pp. 331-354 ◽  
Author(s):  
WENCHAO CAO ◽  
SIMON WILLIAMS ◽  
NICOLAS FLAMENT ◽  
SABIN ZAHIROVIC ◽  
CHRISTOPHER SCOTESE ◽  
...  
Keyword(s):  
Early Carboniferous ◽  
Bimodal Distribution ◽  
Global Scale ◽  
Plate Motion ◽  
Oceanic Circulation ◽  
Geological Time ◽  
Climatic Zones ◽  
Deep Time ◽  
Continental Area ◽  
Poleward Shift

AbstractWhether the latitudinal distribution of climate-sensitive lithologies is stable through greenhouse and icehouse regimes remains unclear. Previous studies suggest that the palaeolatitudinal distribution of palaeoclimate indicators, including coals, evaporites, reefs and carbonates, has remained broadly similar since the Permian period, leading to the conclusion that atmospheric and oceanic circulation control their distribution rather than the latitudinal temperature gradient. Here we revisit a global-scale compilation of lithologic indicators of climate, including coals, evaporites and glacial deposits, back to the Devonian period. We test the sensitivity of their latitudinal distributions to the uneven distribution of continental areas through time and to global tectonic models, correct the latitudinal distributions of lithologies for sampling- and continental area-bias, and use statistical methods to fit these distributions with probability density functions and estimate their high-density latitudinal ranges with 50% and 95% confidence intervals. The results suggest that the palaeolatitudinal distributions of lithologies have changed through deep geological time, notably a pronounced poleward shift in the distribution of coals at the beginning of the Permian. The distribution of evaporites indicates a clearly bimodal distribution over the past ~400 Ma, except for Early Devonian, Early Carboniferous, the earliest Permian and Middle and Late Jurassic times. We discuss how the patterns indicated by these lithologies change through time in response to plate motion, orography, evolution and greenhouse/icehouse conditions. This study highlights that combining tectonic reconstructions with a comprehensive lithologic database and novel data analysis approaches provide insights into the nature and causes of shifting climatic zones through deep time.

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