Changes in the bird fauna of Uttara Kannada, India, in relation to changes in land use over the past century

1990 ◽  
Vol 52 (1) ◽  
pp. 37-48 ◽  
Author(s):  
R.J. Ranjit Daniels ◽  
N.V. Joshi ◽  
Madhav Gadgil
Keyword(s):  
Land Use ◽  
The Past ◽  

In the Surface Water Acidification Project (SWAP) sediment profiles from five Scandinavian sites were analysed for 210 Pb by using refined isotope dilution alpha spectrometry. The 210 Pb parameters of these lakes were very similar to those obtained for protected forest lakes with no land-use activities. These data demonstrated almost exclusive atmospheric inputs and an internal deposition regulated by the organic fractionation and the grain-size distribution in the sediments. Preliminary speciation experiments showed minor losses of 210 (≤ 5%) through enhanced dissolution of fulvic compounds at acid conditions (pH ≥ 4). The sediment accumulation rates (constant rate of unsupported 210 Pb supply (CRS) model) of the lakes gradually increased, by at least a factor of three, over the past century although 210 Pb parameters did not show any strong signs of enhanced land-use activities. This is perhaps caused by more efficient preservation of the sediments through humic precipitation under more acid conditions.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Madleina Gerecke ◽  
Oskar Hagen ◽  
Janine Bolliger ◽  
Anna M. Hersperger ◽  
Felix Kienast ◽  
...  

Abstract Landscapes have been changing at an increasing pace over the past century, with countless consequences for humans and their surrounding environments. Information on past and future land use change and the resulting alteration of landscape service provisioning are valuable inputs for policy making and planning. Land use transitions in Switzerland (2009–2081) were simulated using statistical models informed by past land use changes as well as environmental and socio-economic data (1979–2009). By combining land use types with additional contextual landscape information, eight landscape services, based on both (semi-)natural and artificial landscapes, were quantified and investigated on how they would evolve under projected land use changes. Investigation of land use transitions showed region-dependent trends of urban expansion, loss of agricultural area, and forest regrowth. Landscapes cannot accommodate all services simultaneously, and this study sheds light on some competing landscape services, in particular (i) housing at the expense of agriculture and (ii) vanishing recreation opportunities around cities as city limits, and thus housing and job provisioning, expand. Model projections made it possible to pinpoint potential trade-offs between landscape services in a spatially explicit manner, thereby providing information on service provision losses and supporting planning. While future changes are presented as extrapolations of the patterns quantified in the past, policy changes might cause deviation from the projections presented here. A major challenge is to produce socio-economic and policy scenarios to inform projections that will differ from current landscape management. Given that urban sprawl is affecting many land surfaces globally, the approach used here could be generalized to other countries in similar situations.


2005 ◽  
Vol 30 (4-5) ◽  
pp. 267-276 ◽  
Author(s):  
Min Tu ◽  
Michael J. Hall ◽  
Pieter J.M. de Laat ◽  
Marcel J.M. de Wit

Author(s):  
Tatiana Vorobyova ◽  
Yelaman Smagulov

The agricultural use of land resources in the dry steppe regions of Northern Kazakhstan has undergone significant changes over the past century and continues to change at the present time. The middle position in the region is occupied by the Akmola region, one of the leading agricultural regions, where 9.3 % of the country’s gross agricultural output is produced. The main branches of agriculture in the region are grain farming and dairy and beef cattle breeding. The study of the change in the ratio of the areas of arable and pasture lands, the changes that have occurred in the state of agricultural landscapes as a result of long-term use is important for the further development of the agricultural industry in the region. Using the example of the Astrakhan district of the Akmola region, typical for the dry steppe zone, an analysis of changes in the structure of agricultural land from 1953 to 2020 was carried out. with the help of a series of digital maps compiled from detailed maps of scientific reference atlases of Northern Kazakhstan in 1964, 1970, remote sensing data of different times, archival materials and data of modern statistics. The resulting maps visualize significant changes in cropland areas within the study area over the past 70 years. Seven main periods were identified, during which the most significant changes in the structure of land use occurred as a result of political, economic and natural factors. During the years of development of virgin and fallow lands, the highest rates of increase in arable land were observed, which continued on a smaller scale until 1990. The period from 1991-1999 characterized by a large-scale reduction of arable land and abandonment of pastures. This was followed by two periods of gradual restoration of the use of arable and rangelands. Compiled comprehensive map of the dynamics of agricultural land use from 1988 to 2020 made it possible to identify spatial and temporal patterns in changes in the structure of agricultural land use, to determine to which specific natural types of lands the abandoned lands belonged and to which restored ones. Spatial analysis showed that over the past 30, more than half of the area’s area has not changed the type of land use. The results obtained are used to select the optimal ratio of arable and pasture lands in the structure of agricultural land use, as well as to develop a strategy for the rational use of agricultural land in the zone of risky farming.


2015 ◽  
Vol 112 (21) ◽  
pp. 6579-6584 ◽  
Author(s):  
Carsten Meyer-Jacob ◽  
Julie Tolu ◽  
Christian Bigler ◽  
Handong Yang ◽  
Richard Bindler

Organic carbon concentrations have increased in surface waters across parts of Europe and North America during the past decades, but the main drivers causing this phenomenon are still debated. A lack of observations beyond the last few decades inhibits a better mechanistic understanding of this process and thus a reliable prediction of future changes. Here we present past lake-water organic carbon trends inferred from sediment records across central Sweden that allow us to assess the observed increase on a centennial to millennial time scale. Our data show the recent increase in lake-water carbon but also that this increase was preceded by a landscape-wide, long-term decrease beginning already A.D. 1450–1600. Geochemical and biological proxies reveal that these dynamics coincided with an intensification of human catchment disturbance that decreased over the past century. Catchment disturbance was driven by the expansion and later cessation of widespread summer forest grazing and farming across central Scandinavia. Our findings demonstrate that early land use strongly affected past organic carbon dynamics and suggest that the influence of historical landscape utilization on contemporary changes in lake-water carbon levels has thus far been underestimated. We propose that past changes in land use are also a strong contributing factor in ongoing organic carbon trends in other regions that underwent similar comprehensive changes due to early cultivation and grazing over centuries to millennia.


2020 ◽  
Vol 4 (4) ◽  
pp. 365-381
Author(s):  
Ny Anjara Fifi Ravelomanantsoa ◽  
Sarah Guth ◽  
Angelo Andrianiaina ◽  
Santino Andry ◽  
Anecia Gentles ◽  
...  

Seven zoonoses — human infections of animal origin — have emerged from the Coronaviridae family in the past century, including three viruses responsible for significant human mortality (SARS-CoV, MERS-CoV, and SARS-CoV-2) in the past twenty years alone. These three viruses, in addition to two older CoV zoonoses (HCoV-229E and HCoV-NL63) are believed to be originally derived from wild bat reservoir species. We review the molecular biology of the bat-derived Alpha- and Betacoronavirus genera, highlighting features that contribute to their potential for cross-species emergence, including the use of well-conserved mammalian host cell machinery for cell entry and a unique capacity for adaptation to novel host environments after host switching. The adaptive capacity of coronaviruses largely results from their large genomes, which reduce the risk of deleterious mutational errors and facilitate range-expanding recombination events by offering heightened redundancy in essential genetic material. Large CoV genomes are made possible by the unique proofreading capacity encoded for their RNA-dependent polymerase. We find that bat-borne SARS-related coronaviruses in the subgenus Sarbecovirus, the source clade for SARS-CoV and SARS-CoV-2, present a particularly poignant pandemic threat, due to the extraordinary viral genetic diversity represented among several sympatric species of their horseshoe bat hosts. To date, Sarbecovirus surveillance has been almost entirely restricted to China. More vigorous field research efforts tracking the circulation of Sarbecoviruses specifically and Betacoronaviruses more generally is needed across a broader global range if we are to avoid future repeats of the COVID-19 pandemic.


VASA ◽  
2018 ◽  
Vol 47 (3) ◽  
pp. 165-176 ◽  
Author(s):  
Katrin Gebauer ◽  
Holger Reinecke

Abstract. Low-density lipoprotein cholesterol (LDL-C) has been proven to be a causal factor of atherosclerosis and, along with other triggers like inflammation, the most frequent reason for peripheral arterial disease. Moreover, a linear correlation between LDL-C concentration and cardiovascular outcome in high-risk patients could be established during the past century. After the development of statins, numerous randomized trials have shown the superiority for LDL-C reduction and hence the decrease in cardiovascular outcomes including mortality. Over the past decades it became evident that more intense LDL-C lowering, by either the use of highly potent statin supplements or by additional cholesterol absorption inhibitor application, accounted for an even more profound cardiovascular risk reduction. Proprotein convertase subtilisin/kexin type 9 (PCSK9), a serin protease with effect on the LDL receptor cycle leading to its degradation and therefore preventing continuing LDL-C clearance from the blood, is the target of a newly developed monoclonal antibody facilitating astounding LDL-C reduction far below to what has been set as target level by recent ESC/EAS guidelines in management of dyslipidaemias. Large randomized outcome trials including subjects with PAD so far have been able to prove significant and even more intense cardiovascular risk reduction via further LDL-C debasement on top of high-intensity statin medication. Another approach for LDL-C reduction is a silencing interfering RNA muting the translation of PCSK9 intracellularly. Moreover, PCSK9 concentrations are elevated in cells involved in plaque composition, so the potency of intracellular PCSK9 inhibition and therefore prevention or reversal of plaques may provide this mechanism of action on PCSK9 with additional beneficial effects on cells involved in plaque formation. Thus, simultaneous application of statins and PCSK9 inhibitors promise to reduce cardiovascular event burden by both LDL-C reduction and pleiotropic effects of both agents.


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