Assessing Land Cover Change and Anthropogenic Disturbance in Wetlands Using Vegetation Fractions Derived from Landsat 5 TM Imagery (1984–2010)

Robertson, Laura Dingle; King, Douglas J.; Davies, C. S. L.

doi:10.1007/s13157-015-0696-5

Cited by 21 publications

(14 citation statements)

References 35 publications

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“…Although the early indigenous Māori settlers caused extensive deforestation of dryland forests by burning (Argiriadis et al, 2018;McWethy et al, 2010), wetland extent was minimally affected until after European arrival (1800s) when wetland loss accelerated rapidly for development and agriculture (McGlone, 2009). In the last 160 years, logging, fires and drainage have reduced wetland extent to less than 10% of its original cover making wetland ecosystems highly-threatened (Robertson et al, 2015). The most significant loss of wetlands occurred between 1920 and 1980 due to fragmentation and drainage (Taylor and Smith, 1997) to make way for large-scale agricultural activities.…”

Section: Study Sitesmentioning

confidence: 99%

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

McKeown

Wilmshurst

Duckert

et al. 2019

European Journal of Protistology

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Methodological advances are essential for robust ecological research. Quantitative reconstructions of environmental conditions using testate amoebae rely on sound taxonomy. While the taxonomy of large species is relatively well resolved, this is not the case for most small taxa (typically <45 m long). In New Zealand, peatlands contain a diversity of both cosmopolitan and characteristic large southern endemic taxa, but also have a high abundance of small taxa. The latter are often lumped into morphotypes reducing their value as ecological indicators. In this study, we demonstrate how (a) lumping small taxa versus splitting them into unique types, and (b) including or excluding them from community analysis influenced their ecological inference. We assessed testate amoeba composition in six peat bogs from New Zealand, three that were moderately-to-highly impacted, and three that were non-impacted. Environmental variables were measured at each sampling site and the surface testate amoeba community patterns and community-environment relationships compared. We found a clear division between impacted and non-impacted sites. Several distinct small taxa were more strongly related to water-table depth and conductivity, while the larger taxa were more correlated to pH. These results show that improved taxonomic resolution of small taxa can provide more informed environmental assessment.

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Section: Study Sitesmentioning

confidence: 99%

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

McKeown

Wilmshurst

Duckert

et al. 2019

European Journal of Protistology

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“…Given the interest in capturing not only wetland area, but also change in wetland status and extent over time, multi-temporal investigations are increasingly of interest. The use of time series satellite imagery has been demonstrated [17,19,20]. Dingle Robertson et al [19] showed for two wetland complexes in Ontario, Canada, over a 26-year period using Landsat-5 Thematic Mapper data, an ability to capture a range of wetland dynamics as well as inference of the drivers of change.…”

Section: Introductionmentioning

confidence: 99%

A National Assessment of Wetland Status and Trends for Canada’s Forested Ecosystems Using 33 Years of Earth Observation Satellite Data

Wulder

Campbell

et al. 2018

Remote Sensing

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Wetlands are important globally for supplying clean water and unique habitat, and for storing vast amounts of carbon and nutrients. The geographic extent and state of wetlands vary over time and represent a dynamic land condition rather than a permanent land cover state. Herein, we combined a time series of land cover maps derived from Landsat data at 30-m resolution to inform on spatial and temporal changes to non-treed and treed wetland extents over Canada’s forested ecosystems (>650 million ha) from 1984 to 2016. Overall, for the period, 1984 to 2016, we found the extent of wetlands (non-treed and treed combined) in Canada’s forested ecosystems to be stable, with some regional variability, often resulting from offsetting decreases and increases within a given ecozone. Notwithstanding difficulties in using optical satellite data for mapping a land condition, by accumulating wetland evidence via earth observations consistently through multiple decades, our results capture the trends in wetland cover over a previously unmapped, national extent at a level of spatial detail and temporal reach suitable for further focused interpretations of wetlands and drivers and projections of wetland dynamics.

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“…Wetlands also provide flood protection, protection from storm and wave damage, water quality improvements through the filtering of agricultural and industrial waste, and aquifer recharge [6][7][8]. Although wetlands play an important role in environmental processes and provide many ecological services for mankind, they are under increasing threats from climate change, dredge and fill operations, hydrologic variations, pollutant runoff, eutrophication, impoundments, and land modification, as well as the growing load placed on wetlands by agriculture, aquaculture, forestry, and development [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Remote Sensing of Spatiotemporal Changes in Wetland Geomorphology Based on Type 2 Fuzzy Sets: A Case Study of Beidagang Wetland from 1975 to 2015

Huo

Guo

et al. 2017

Remote Sensing

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Few studies have considered the spatiotemporal changes in wetland land cover based on type 2 fuzzy sets using long-term series of remotely sensed data. This paper presents an improved interval type 2 fuzzy c-means (IT2FCM*) approach to analyse the spatial and temporal changes in the geomorphology of the Beidagang wetland in North China from 1975 to 2015 based on long-term Landsat data. Unlike traditional type 1 fuzzy c-means methods, the IT2FCM* algorithm based on interval type-2 fuzzy set has an ability to better handle the spectral uncertainty. Four indexes were adopted to validate the separability of classes with the IT2FCM* algorithm. These four validity indexes showed that IT2FCM* obtained better results than traditional methods. Additionally, the accuracy of the classification results was assessed based on the confusion matrix and kappa coefficient, which were high for the analysis of wetland landscape changes. Based on the analysis of separability of classes with the IT2FCM* algorithm using four validity indexes, the classification results, and the membership value images, the long-term series of satellite datasets were processed using the IT2FCM* method, and the study area was classified into six classes. Because water resources and vegetation are two key wetland components, the water resource dynamics and vegetation dynamics, based on the normalized difference vegetation index (NDVI), were analysed in detail according to the spatiotemporal classification results. The results show that the changes in vegetation types have historically been associated with water resource variations and that water resources play an important role in the evolution of vegetation types.

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Assessing Land Cover Change and Anthropogenic Disturbance in Wetlands Using Vegetation Fractions Derived from Landsat 5 TM Imagery (1984–2010)

Cited by 21 publications

References 35 publications

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

A National Assessment of Wetland Status and Trends for Canada’s Forested Ecosystems Using 33 Years of Earth Observation Satellite Data

Remote Sensing of Spatiotemporal Changes in Wetland Geomorphology Based on Type 2 Fuzzy Sets: A Case Study of Beidagang Wetland from 1975 to 2015

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Assessing Land Cover Change and Anthropogenic Disturbance in Wetlands Using Vegetation Fractions Derived from Landsat 5 TM Imagery (1984–2010)

Cited by 21 publications

References 35 publications

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

A National Assessment of Wetland Status and Trends for Canada’s Forested Ecosystems Using 33 Years of Earth Observation Satellite Data

Remote Sensing of Spatiotemporal Changes in Wetland Geomorphology Based on Type 2 Fuzzy Sets: A Case Study of Beidagang Wetland from 1975 to 2015

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Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands