Reduced Vegetation Cover Research Articles

Shaping Sustainable Urban Environments by Addressing the Hydro-Meteorological Factors in Landslide Occurrence: Ciuperca Hill (Oradea, Romania).

Romania is one of the countries severely affected by numerous natural hazards, where landslides constitute a very common geomorphic hazard with strong economic and social impacts. The analyzed area, known as the “Ciuperca Hill”, is located in Oradea (NW part of Romania) and it has experienced a number of landsliding events in previous years, which have endangered anthropogenic systems. Our investigation, focused on the main causal factors, determined that landslide events have rather complex components, reflected in the joint climatological characteristics, properties of the geological substrate, and human activity that further contributed to the intensive change of landscape and acceleration of slope instability. Analysis of daily precipitation displays the occurrence and intensive distribution between May and September. Higher values of rainfall erosivity (observed for the 2014–2017 period), are occurring between April and August. Erosivity density follows this pattern and indicates high intensity events from April until October. SPI index reveals the greater presence of various wet classes during the investigated period. Geological substrate has been found to be highly susceptible to erosion and landsliding when climatological conditions are suitable. Accelerated urbanization and reduced vegetation cover intensified slope instability. The authors implemented adequate remote-sensing techniques in order to monitor and assess the temporal changes in landslide events at local level. Potential solutions for preventative actions are given in order to introduce and conduct qualitative mitigation strategies for shaping sustainable urban environments. Results from this study could have implications for mitigation strategies at national, regional, county, and municipality levels, providing knowledge for the enhancement of geohazard prevention and appropriate response plans.

The response of culturally important plants to experimental warming and clipping in Pakistan Himalayas.

The relative effects of climate warming with grazing on medicinally important plants are not fully understood in Hindukush-Himalaya (HKH) region. Therefore, we combined the indigenous knowledge about culturally important therapeutic plants and climate change with experimental warming (open-top chambers) and manual clipping (simulated grazing effect) and compared the relative difference on aboveground biomass and percent cover of plant species at five alpine meadow sites on an elevation gradient (4696 m-3346 m) from 2016-2018. Experimental warming increased biomass and percent cover throughout the experiment. However, the interactive treatment effect (warming x clipping) was significant on biomass but not on percent cover. These responses were taxa specific. Warming induced an increase of 1 ± 0.6% in Bistorta officinalis percent cover while for Poa alpina it was 18.7 ± 4.9%. Contrastingly, clipping had a marginally significant effect in reducing the biomass and cover of all plant species. Clipping treatment reduced vegetation cover & biomass by 2.3% and 6.26%, respectively, but that was not significant due to the high variability among taxa response at different sites. It was found that clipping decreased the effects of warming in interactive plots. Thus, warming may increase the availability of therapeutic plants for indigenous people while overgrazing would have deteriorating effects locally. The findings of this research illustrate that vegetation sensitivity to warming and overgrazing is likely to affect man-environment relationships, and traditional knowledge on a regional scale.

Assessing the effects of vegetation change on urban land surface temperature using remote sensing data: The case of Addis Ababa city, Ethiopia

Land Surface Temperature (LST) plays an essential role in regulating the temperature and surface processes of land features. Advancement in remote sensing has paved the way for the use of satellite data to estimate land surface temperature. The objective of this study was to estimate changes in vegetation and LST from Landsat TM (Thematic Mapper) of 1985 and Landsat 8 OLI (Operational Land Imager) of 2015 for Addis Ababa City, Ethiopia. Land use/land cover classification using supervised image classification and the maximum likelihood algorithm method was applied to study changes in land use/land cover from 1985 to 2015. Brightness temperature, Land Surface Emissivity (LSE) and Normalized Difference Vegetation Index (NDVI) were computed to estimate land surface temperature. The result of the study showed a reduction of vegetation cover and rapid expansion of built-up area against grazing lands and other land use classes from 1985 to 2015. The area of built-up has increased from 18.23% in 1985 to 33.86% in 2015. In the centre of the city and areas with low vegetation cover, land surface temperature has shown an increase of 3–8 °C from 1985 to 2015. Correlation analysis showed a negative correlation between NDVI and land surface temperature in all sub-cities of Addis Ababa. The findings of this study could support the designing of suitable strategies to mitigate urban heat stress.

Análise de mudanças na cobertura vegetal do Pará utilizando o Google Earth Engine

Nos últimos anos o processo de desmatamento na Floresta Amazônica vem se intensificando. Entre as principais causas, destacam-se o estímulo a políticas de ocupação territorial, exploração madeireira e aumento das áreas destinadas a pecuária e cultivos agrícolas. No Brasil, a Floresta envolve nove Estados que fazem parte da Bacia amazônica cada um deles possuindo porções da Floresta Amazônica. Dentre esses Estados, o Pará é o que mais contribuiu para o aumento do desflorestamento. Neste sentido, este trabalho tem como objetivo analisar a dinâmica da cobertura vegetal do Pará entre os anos de 1989 e 2019 por meio do processamento de imagens de satélite na plataforma Google Earth Engine (GEE). Para a execução deste trabalho foi calculado, através de programação em linguagem JavaScript no GEE, o Índice de Vegetação por Diferença Normalizada (NDVI). Foram utilizadas imagens do satélite Landsat-5/TM e Landsat-8/OLI-TIRS. Os resultados mostraram uma redução significativa na cobertura vegetal entre 1989 e 2019 principalmente na região leste do Estado. Destaca-se a importância do GEE e do NDVI no monitoramento e controle ambiental pois através dos resultados obtidos foi possível constatar mudanças na cobertura vegetal que a Floresta vem sofrendo ao longo dos anos.

Evaluating the Urban Canopy Scheme TERRA_URB in the COSMO Model for Selected European Cities

The increase in built surfaces constitutes the main reason for the formation of the Urban Heat Island (UHI), that is a metropolitan area significantly warmer than its surrounding rural areas. The urban heat islands and other urban-induced climate feedbacks may amplify heat stress and urban flooding under climate change and therefore to predict them correctly has become essential. Currently in the COSMO model, cities are represented by natural land surfaces with an increased surface roughness length and a reduced vegetation cover, but this approach is unable to correctly reproduce the UHI effect. By increasing the model resolution, a representation of the main physical processes that characterize the urban local meteorology should be addressed, in order to better forecast temperature, moisture and precipitation in urban environments. Within the COSMO Consortium a bulk parameterization scheme (TERRA_URB or TU) has been developed. It parametrizes the effects of buildings, streets and other man-made impervious surfaces on energy, moist and momentum exchanges between the surface and atmosphere, and additionally accounts for the anthropogenic heat flux as a heat source from the surface to the atmosphere. TU implements an impervious water-storage parameterization, and the Semi-empirical Urban canopy parametrization (SURY) that translates 3D urban canopy into bulk parameters. This paper presents evaluation results of the TU scheme in high-resolution simulations with a recent COSMO model version for selected European cities, namely Turin, Naples and Moscow. The key conclusion of the work is that the TU scheme in the COSMO model reasonably reproduces UHI effect and improves air temperature forecasts for all the investigated urban areas, despite each city has very different morphological characteristics. Our results highlight potential benefits of a new turbulence scheme and the representation of skin-layer temperature (for vegetation) in the model performance. Our model framework provides perspectives for enhancing urban climate modelling, although further investigations in improving model parametrizations, calibration and the use of more realistic urban canopy parameters are needed.

The effect of different logging regimes on the ecomorphological structure of stream fish assemblages in the Brazilian Amazon

AbstractWe evaluated the effects of changes in habitat structure resulting from conventional logging (CL) and reduced-impact logging (RIL) on the ecomorphological structure of stream fish assemblages in the eastern Brazilian Amazon, investigating (1) which habitat characteristics are influenced by different logging methods, (2) the differences in the ecomorphological structure of fish assemblages between two logging methods and undisturbed forest (UF), and (3) the relationships between ecomorphological traits of fish assemblages and habitat variables. We measured 13 habitat variables and characterized 11 ecomorphological traits of 55 fish species collected in 34 sampling sites (stream stretches) located in CL, RIL, and UF. In logged areas, the streams present a fine sediment increase and reduced vegetation cover, while in the UF a greater amount of natural shelter and more cover vegetation were observed. These environmental changes selected ecomorphological traits of stream fish assemblages, recording a greater relative width of the mouth in UF, higher ventral flattening index in RIL, or greater relative head length, and higher caudal peduncle compression index in CL. In this sense, we recommend that logging practices, including RIL, should be reviewed as a means of adopting better strategies to minimize human disturbances in streams.

Spatial Assessment of Urbanization Using GIS in Selected Neighbourhoods of Port Harcourt Metropolis

This study analyzed the spatial assessment of urbanization in Mgbougba, PH Township, Orazi Rumueme, and Eligbam Rumueme using GIS to determine the spatial and temporal changes. This study adopted data from a secondary source, which includes Landsat (7) TM Thematic Mapper of 1999, 2009 and 2019 of the study areas which were further analyzed to determine spatial and temporal changes that have occurred in the study areas. Findings from this study based on the classified Landsat imageries revealed that in Mgbougba, spatial changes were observed as a result of an increase in built area value of 591 in 1999 to 4066 in 2009 and to 6661 in 2019, hence, caused a reduction in vegetation cover with the value of 5038 in 1999 to 3733 in 2009 and to 1515 in 2019 and also a reduction of water body with a value of 363 in 1999 to 276 in 2009, with the absence of water body in 2019. Spatial changes also occurred in PH Township built-up areas indicating an increase in signature values from 3329 in 1999 to 4646 in 2009 and to 6276 in 2019. There was a decrease in vegetation cover of 2044 in 1999 to 1325 in 2009 and 1258 in 2019, bare land also showed a reduction in signature values of 1239 in 1999 to 1142 in 2009 and 791 in 2019 and finally a reduction of water body from 700 in 1999 to 658 in 2009 and 600 in 2019. In Orazi Rumueme, it revealed there was a significant expansion of built-up area value from 2514 in 1999 to 2978 in 2009 and 3936 in 2019. There was a decline in vegetation cover with a value of 678 in 1999 to 517 in 2009 and 426 in 2019. Spatial changes in Eligbam Rumueme, showed that built-up area value increased from 780 in 1999 to 878 in 2009 and 1164 in 2019, thus, resulting to a reduction in the vegetation cover with a value from 625 in 1999 to 537 in 2009 and 251 in 2019 which indicated that urbanization led to significant spatial changes in built-up areas, vegetation cover, bare land and water body in the selected neighborhoods. However, the identified pattern of urbanization in the study areas showed that the selected neighborhoods possessed more built-up areas as of 2019 when compared to 1999 and 2009. The spatial analysis of urbanization using GIS aided in understanding the spatial changes that have occurred in the selected neighborhoods and provided plans for sustainable development.

Grazing and climate change have site‐dependent interactive effects on vegetation in Asian montane rangelands

Abstract Climate over Asian montane rangelands is changing faster than the global average, posing serious threats to the future of the region's livestock‐based economies and cultures. Effects of climate change on rangeland vegetation likely depend on grazing by herbivores but the potential responses of vegetation to such changes in climate and grazing regimes remain unclear. We examined vegetation responses to experimentally simulated climate change (warming, drought and increased rainfall) and grazing (clipping vegetation) between 2015 and 2018 at two mountain rangeland sites: Spiti valley, in the Indian Trans‐Himalaya and Tost, in the Gobi‐Altai Mountains in Mongolia. Clipping and climate change manipulations interactively reduced vegetation cover and biomass but did not affect species richness. Treatment effects and their interactions varied between sites. In ungrazed plots, vegetation cover and biomass declined sharply in response to warming (18%–35%) and drought (20%–50%) at the two sites, and, surprisingly also declined slightly in response to increased rainfall (20%) at Tost. While the effects of climate treatments were largely similar in the grazed and ungrazed plots in Tost, they were larger in the ungrazed plots in Spiti. The decline in vegetation cover was driven by a decline in the cover of both forbs and grasses. In combination, grazing and warming (Tost) or drought (Spiti) had sub‐additive effects, that is, the decrease in vegetation cover in response to grazing and warming/drought was less than the sum of their independent effects but greater than the effect of either manipulation alone. Of the two, warming had a greater effect than drought at the more arid site (Tost), whereas drought had a larger effect at the more mesic site (Spiti). Synthesis and applications. Our findings show that future changes in climate, including just over 1°C of warming, could undermine the sustainability of pastoral economies and the persistence of wildlife across Asian montane rangelands. Furthermore, grazing by herbivores will play an important role in mediating rangeland responses to climate change; thus, pasture management in concert with local pastoralists will be crucial in mitigating the adverse effects of climate change on rangelands, pastoral livelihoods and wildlife populations.

Assessing land degradation induced by recreational activities in the Algodones Dunes, California using MODIS satellite imagery

This research investigated spatial and temporal environmental changes associated with climatic variability and off-highway vehicle (OHV) activity in the Algodones Dunes, California, using time-series analysis of Moderate Resolution Imaging Spectroradiometer imagery from 2001 to 2016. We compared changes in land cover, surface albedo, and surface temperatures between the Imperial Sand Dunes Recreation Area (ISDRA) and areas with no OHV activity in the North Algodones Dunes Wilderness area (NADW). Both areas showed a decreasing normalized difference vegetation index (NDVI) and an increasing albedo from 2001 to 2016; however, ISDRA had a lower NDVI value and higher albedo compared to the adjacent NADW. Transects across these adjoining areas revealed substantial differences in daytime and nighttime land surface temperatures. ISDRA had an appreciably higher mean daytime temperature and a lower mean nighttime temperature compared to those within NADW. Results suggest direct association between increasing OHV activity and reduced vegetation cover, increased soil exposure, and higher daytime temperatures in the Algodones Dunes. We recommend enhanced monitoring of ecosystem and land use changes coupled with enhanced land use management to reduce the contributions of recreational OHV activity on land degradation and to maintain habitat for key species and ecosystems of interest in the dune field.

Impacts of Climate Change on the Water Resources of the Kunduz River Basin, Afghanistan

The Kunduz River is one of the main tributaries of the Amu Darya Basin in North Afghanistan. Many communities live in the Kunduz River Basin (KRB), and its water resources have been the basis of their livelihoods for many generations. This study investigates climate change impacts on the KRB catchment. Rare station data are, for the first time, used to analyze systematic trends in temperature, precipitation, and river discharge over the past few decades, while using Mann–Kendall and Theil–Sen trend statistics. The trends show that the hydrology of the basin changed significantly over the last decades. A comparison of landcover data of the river basin from 1992 and 2019 shows significant changes that have additional impact on the basin hydrology, which are used to interpret the trend analysis. There is considerable uncertainty due to the data scarcity and gaps in the data, but all results indicate a strong tendency towards drier conditions. An extreme warming trend, partly above 2 °C since the 1960s in combination with a dramatic precipitation decrease by more than −30% lead to a strong decrease in river discharge. The increasing glacier melt compensates the decreases and leads to an increase in runoff only in the highland parts of the upper catchment. The reduction of water availability and the additional stress on the land leads to a strong increase of barren land and a reduction of vegetation cover. The detected trends and changes in the basin hydrology demand an active management of the already scarce water resources in order to sustain water supply for agriculture and ecosystems in the KRB.

Assessing trends and predicting the cover management factor in a tropical island state using Enhanced Vegetation Index

Soil erosion is a complex process involving multiple factors that contribute to the amount of soil loss. The amount of vegetation cover is one of the main factors used to estimate soil loss and is an important risk factor in informing land use management and soil conservation policies. Cover/crop management (C-factor) is a dynamic soil loss factor and analysing C-factor trends in the context of both space and time, to build a multi-dimensional data structure, increased the value of the trend analysis. The objectives of the study were to (1) utilise EVI dependent static and dynamic predictive equations to compute the C-factor, and (2) to investigate the spatio-temporal changes of the C-factor and hotspots in a tropical small island developing state (SIDS) from 2010 to 2019. ArcGIS Model Builder was utilised to automate the computation of the C-factor using Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) data and compute the ordinary least square regression. Spatio-temporal analysis was performed using the novel emerging hot spot analysis in ArcGIS to identify statistically significant hot and cold spot trends of cover management to locate new, intensifying, persistent, or sporadic hot spot patterns at different time-step intervals. The regression output for the C-factor and EVI values indicated a strong r2, explaining on average 90% of the models. There was no statistically significant (P value > 0.05) increase in C-factor trend over a 10 year period (2010–2019, P-value = 0.92), a 5 year period (2015–2019; P-value = 0.59), or a 3 year period (2017–2019; P-Value = 0.31). Our results showed that intensifying hot spots (27%) were concentrated along the north–south corridor of the study area, highlighting areas with a statistically significant increase of the C-factor, thus a reduction in vegetation cover over the study period. Integrating spatio-temporal data and spatial technology provided vital cover management estimates for soil practitioners and farmers to guide conservation strategies.

Mapping and chronology of coversands and dunes from the Aquitaine basin, southwest France

New stratigraphic (including GPR profiles) and chronological data provide a detailed understanding of the emplacement of aeolian sands in the Aquitaine basin (SW France). The main phase of coversand deposition ranges from 25 ka to 14 ka. The ages cluster around two periods that match Heinrich events (He-2 and He-1) and reflect increased sedimentation in response to aridification and high mean wind speeds. The age distribution is skewed toward recent phases, which likely results from continuous sand recycling. The dunes currently visible in the landscape were formed during the Younger Dryas/very early Holocene and the historical period. The Younger Dryas dunes are inland low parabolic dunes that have been strongly degraded. Only the last phases of the progression of the coastal dunefield are preserved because of coastal erosion. Two depositional phases have been identified, the Dark Ages Cold Period and the Little Ice Age, which correspond to phases of increased storminess already known from the coastal record in Europe. The Dark Ages Cold Period dunes are high parabolic dunes, whereas the Little Ice Age dunes are predominantly barchanoid. The impact of trampling of the dunes by cattle during the latter period, resulting in reduced vegetation cover, and their artificial stabilization by pine forests seems to be the plausible causes of this morphological difference. Overall, the Aquitaine aeolian system is a good example of a mid-latitude coastal to inland system that was intermittently active during the Quaternary, and where the reconfiguration of the coast following sea level fluctuations played an important role in the chronological distribution of sediments.

Geochemical Approach to the Reconstruction of Sedimentation Processes in Kamyshovoye Lake (SE Baltic, Russia) during the Late Glacial and Holocene

The article is devoted to a reconstruction of the sedimentation processes in Kamyshovoye Lake (the Kaliningrad Region, Russia) during the Late Glacial and Holocene. The results of the geochemical analysis of Kamyshovoye Lake’s bottom sediments, accompanied by statistical processing and detailed radiocarbon dating, are presented. It was established that a high proportion of mineral matter dominated in the intervals between 15,000 and 11,400 and between 1400 and 600 cal y BP; enrichment with carbonates was noted between 11,400 and 5200 cal y BP and during the past 600 years; and a high percentage of organic matter was recorded between 7800 and 600 cal y BP. We conclude that the increase in mineral matter was influenced by such factors as reduced vegetation cover due to natural and anthropogenic processes, aeolian transfer, and dead-ice melting during the Late Glacial. The increase in carbonate matter was mainly associated with humidity and the reduction conditions of the lake ecosystem. Organogenic matter content was affected by the autochthonic (biological) productivity of the lake, which directly depends on more favorable climatic conditions.

Changes in grassland cover and in its spatial heterogeneity indicate degradation on the Qinghai-Tibetan Plateau

Arid grassland ecosystems undergo degradation because of increasing environmental and human pressures. Degraded grasslands show vegetation cover reduction and soil-patch development, leading to grassland fragmentation and changes in spatial heterogeneity. Understanding grassland degradation that involves soil-patch development remains a challenge over large areas with limited accessibility such as the Qinghai-Tibetan Plateau. We hypothesized that vegetation cover, its spatial heterogeneity and changes thereof over time retrieved from satellite data can indicate grassland development and degradation levels. To test the hypothesis, we studied these indicators from 2000 to 2016 and related them to previously described degradation levels on the eastern Qinghai-Tibetan Plateau (QTP) in 2004. We further use these indicators to map the new grassland development and degradation levels in 2016.We found that lower vegetation cover does not always indicate a more severe degradation; instead, higher spatial heterogeneity is a better correlate of degradation. Combined temporal changes in grassland cover and its spatial heterogeneity are related to the literature-defined degradation levels. We found that grassland areas on the eastern QTP have moved into new degradation stages from 2000 to 2016 using changes in grassland cover and its spatial heterogeneity as indicators. The normalized difference vegetation index (NDVI) as a proxy for grassland cover declined over time in the literature-defined degraded areas but increased in the desert areas from 2000 to 2016. Spatial heterogeneity generally increased across different degradation levels from 2000 to 2016; however, this increase was less pronounced in severely degraded and slightly deserted areas. Our newly defined degradation levels in 2016 included degradation, desertification, and improving levels. Across our study area, 63% of all areas were classified as degraded and 2% were at risk of desertification. The remaining areas (35%) classified as improving and re-growing occurred in higher-elevation or previously severely degraded grassland. Our study demonstrates that a combination of changes in grassland cover and in its spatial heterogeneity can indicate grassland degradation levels and serve as an early-warning signal for desertification threats.

Impact assessment of urban development patterns on land surface temperature by using remote sensing techniques: a case study of Lahore, Faisalabad and Multan district.

Urban Heat Island (UHI) is related to the theory of higher atmosphere and surface temperature taking place in the city area as compared to the nearby rural areas. The study results explain the advantages of green spaces in urban areas. Landsat TM/OLI concept of 1998 and 2017years was attained from USGS for this work. To find out the land-use and land cover pattern supervised classification, the maximum prospect process is adopted. A total of four classes were mapped for the study area which includes built-up, barren land, vegetation, and water bodies. Effective sensor brightness temperature has been acquired from spectral radiance by using Plank's reverse function. On the basis of surface emissivity, Normalize Difference Vegetation Index (NDVI) classes are used to find out the ultimate temperature of the land surface (LST). The maximum temperature was recorded in the built-up area and barren land of the city and minimum temperatures were noted in areas with a greater cover of vegetation. The presence of UHI temperature is obvious from the land surface temperature views. An increase of 2°C in surface temperature is recorded in district Lahore during the last two decades. Rise of 2.2°C and 2.4°C surface temperature has taken place in Faisalabad and Multan Districts in the last 19years, respectively. In the establishment of a correlation among the LST, built-up, and vegetation, there is a positive sign present in their relation. With the increase in the built-up area, LST does increase as well. Moreover, with the reduction in vegetation cover, the LST is also raised. The study has revealed that there is a need for proper planning for the durable management of urbanization.

Effects of Skidding Operations after Tree Harvesting and Soil Scarification by Felled Trees on Initial Seedling Emergence of Spanish Black Pine (Pinus nigra Arn. ssp. salzmannii)

Skidding operations are thought to have negative impacts on soil emergence because they may increase soil compaction and reduce vegetation cover and the soil’s organic matter content. We investigated whether and to what extent tree harvesting and subsequent skidding initially altered seedling emergence in two Mediterranean forests of Pinus nigra Arn. ssp. salzmannii (Spanish black pine) in the Cuenca Mountains (Spain). Our main objective was to compare the Spanish black pine seedling emergence rate among skid trails, soil areas scarified by felled trees, and areas undisturbed next to harvest operations. In addition, we selected an unmanaged stand as reference, in order to look for evidence of seedling emergence under natural conditions. We measured Spanish black pine seed fall and seedling emergence immediately after harvest operations in two locations in the Cuenca Mountains (Palancares and Majadas forests), which are typical forests in Cuenca Mountains. The results showed that the Palancares site presented higher seed fall in comparison to the Majadas site. In addition, seed fall was higher in the unmanaged stand, as we recorded a higher tree density in this site in comparison to harvested stands (Palancares and Majadas). Furthermore, our results demonstrated differences in seedling emergence between lower elevation drier Palancares and higher elevation wetter Majadas and relative differences in seedling emergence among skid trail, scarified, and undisturbed harvested areas. Finally, the unmanaged stand presented the highest seedling emergence in comparison to scarified, compacted, and non-disturbed harvested areas. Overall, the results suggest a short-term impact of skidding on seedling emergence, which should be considered for future management guidelines of Spanish black pine in the Mediterranean climate.

Baffin Bay late Neogene palynostratigraphy at Ocean Drilling Program Site 645

Analyses of marine and terrestrial palynomorphs of Ocean Drilling Program (ODP) Site 645 in Baffin Bay led us to define a new biostratigraphical scheme covering the late Miocene to Pleistocene based on dinocyst and acritarch assemblages. Four biozones were defined. The first one, from 438.6 m below sea floor (mbsf) to 388 mbsf, can be assigned a late Miocene to early Pliocene age (>4.5 Ma), based on the common occurrence of Cristadinium diminutivum and Selenopemphix brevispinosa. Biozone 2, spanning from an erosional unconformity to a recovery hiatus, is marked by the highest occurrences (HOs) of Veriplicidium franklinii and Cristadinium diminutivum, which suggest an early Pliocene age >3.6 Ma (∼4.5 to ∼3.6 Ma). Biozone 3, above the recovery hiatus and up to 220.94 mbsf, corresponds to a late Pliocene or early Pleistocene age based on occurrences of Bitectatodinium readwaldii, Cymatiosphaera? icenorum, and Lavradosphaera canalis. Finally, between 266.4 and 120.56 mbsf, Biozone 4, marked by the HO of Filisphaera filifera, Filisphaera microornata, and Habibacysta tectata, has an early Pleistocene age (>1.4 Ma). Our biostratigraphy implies that horizon b1 of the Baffin Bay seismic stratigraphy corresponds to the recovery hiatus at ODP Site 645, which suggests a very thick Pliocene sequence along the Baffin Island slope. Dinocyst assemblages and terrestrial palynomorphs in our records indicate that the late Miocene and (or) early Pliocene were characterized by relatively warm coastal surface waters and boreal forest or forested tundra vegetation over adjacent lands. In contrast, the early Pleistocene dinocyst assemblages above the recovery hiatus indicate cold surface waters, while pollen data suggest reduced vegetation cover on adjacent lands.

Effects of wildfire and logging on soil functionality in the short-term in Pinus halepensis M. forests

Salvage logging is thought to have negative impacts on soil functionality because it may increase soil compaction and reduce vegetation cover and soil organic matter content. We investigated whether and to what extent burning and subsequent logging initially altered soil functionality of a Mediterranean forest of Pinus halepensis M. Soil functionality indicators (e.g. soil enzyme activities, basal soil respiration, glomalin-related soil protein, and microbial carbon) were measured in March and October 2017 in unburned forest plots, nearby plots severely burned by wildfire in July 2016, and nearby burned plots severely burned by wildfire and then logged in December 2016 using a lightweight agricultural tractor. The results showed significant differences among three groups: unburned soils sampled in spring (1) and autumn (2), and burned soils (not subject or subject to logging) sampled in spring and autumn. In unburned plots, seasonality had a significant effect, which disappeared in burned plots regardless of whether they had been logged. The burned plots had higher content of organic matter and total nitrogen than the unburned soils but they were not correlated to higher soil respiration or microbial biomass. There were not any differences in any of the soil functionality indicators between the unlogged and logged burned plots. In addition, the burned plots had a higher glomalin-related soil protein content than the unburned soil in the autumn measurement. Overall, the results suggest a short-term wildfire impact of soil properties whereas logging using a lightweight tractor produced no significant impacts in this sparse Mediterranean pine forest.

Geospatial assessment of ecosystem health of coastal urban wetlands in Ghana

A comprehensive assessment of ecosystem health of wetlands is needed to guide protection and restoration activities. However, the conventional methods used in evaluating ecosystem health of wetlands largely rely on field observational data which often do not provide spatio-temporal perspectives to the assessment. Geospatial assessment of remotely sensed data has enormous potentials for assessing ecosystem health of wetlands at different temporal and spatial scales. This study employed geospatial techniques to assess ecosystem health of Densu Delta, Sakumo II and Muni-Pomadze Ramsar Sites over a 32-year period using structure, function and resilience indicators. Landsat satellite images of 1985, 2002 and 2017 were obtained for this study. Analytic hierarchy process (AHP) was used to weight the indicators. The importance of the ecosystem health indicators in decreasing order was as follows: Structure > Resilience > Function. The findings of the study also indicated that ecosystem health of the wetlands progressively deteriorated in 2002 and 2017 compared to the reference year of 1985. In 2002, the Densu Delta experienced the least decline (11.8%) from the 1985 state among the three wetlands and Sakumo II recorded the highest deterioration (38.0%). Unlike 2002, in 2017 the health of the Densu Delta experienced the worse deterioration (46.3%) whereas Sakumo II recorded the least decline (26.2%). Ecosystem health of Muni-Pomadze Ramsar Site deteriorated at a similar magnitude, 27.0% and 29.1% in 2002 and 2017, respectively. The critical underlying factor for the degradation of the wetlands is urbanization largely due to increase in human population which led to the expansion of built-up areas in the wetlands, fragmentation of natural land use and land cover (LULC) classes and reduction of vegetation cover.

Resetting Southern Tibet: The serious challenge of obtaining primary records of Paleoaltimetry

Abstract Over the last several decades a number of studies have attempted to reconstruct the rise of the Himalaya and Tibet since India-Asia collision began in the early Cenozoic, with rather contradictory results. Here, we evaluate the efforts at reconstructing the history of this major mountain-building event as archived in oxygen, carbon, and clumped isotope records from carbonates exposed on the southern Tibetan Plateau. We find that a number of potential isotopic records of paleoaltimetry from Tibet – using both conventional oxygen and clumped isotope systems–may have been reset during burial and heating. Without exception, the marine δ18O values of Cretaceous and Paleogene marine carbonates across the orogen have been reset from their primary values of 0 ± 4‰ (VPDB) to lower values between −5 and −20‰, most conspicuously in the Indo-Asian suture zone. For this and other reasons, we view isotopic records of paleoaltimetry from the suture zone and adjacent Gangdese arc with great caution, especially early Cenozoic basin sediments that have experienced similar burial and heating as the underlying marine limestones. Outside the suture zone/arc, marine carbonates retain the isotopic imprint of low-elevation, meteoric diagenesis, a result that supports paleoaltimetric reconstruction from these areas using younger non-marine carbonates. We are even more cautious about temperature reconstructions using clumped isotope analyses, which previous studies suggest are sensitive to resetting at modest burial temperatures. With a few possible exceptions, primary clumped isotope values have probably not withstood the elevated temperatures of the suture zone and magmatic arc, nor burial depths of >3 km in basins outside the suture. In light of susceptibility to alteration of oxygen isotopes in carbonates in orogenic belts, future paleoaltimetric reconstruction prior to the Miocene on the Tibetan Plateau should couple δ18O, Δ47, and Δ'17O analysis of carbonates with analysis of noncarbonate archives—such as silicates and organic matter— that are less susceptible to resetting. Carbon, unlike oxygen, isotopic values from paleosol carbonate are well preserved from all periods, due to the very low C/O ratio of most altering fluids. Samples from within the suture zone yield a record of paleo-vegetation change covering much of the Cenozoic. Carbon isotopic values from paleosols have no analog among modern Tibetan soils and most resemble in appearance and chemical composition the vegetated soils in the lowlands of northern India today. Carbon isotopes from paleosols depict a major reduction in vegetation cover in the suture zone since 20 Ma, probably due to a combination of uplift of the suture zone and global cooling. Northward on the Lhasa and Qiantang terranes, the landscape was less vegetated in the Oligocene compared to the contemporaneous suture zone, but more vegetated and less arid than it is today.