Substantial long‐term loss of alpha and gamma diversity of lake invertebrates in a landscape exposed to a drying climate

2021 ◽  
Author(s):  
S.T. Atkinson ◽  
D. Cale ◽  
A. Pinder ◽  
J.M. Chambers ◽  
S.A. Halse ◽  
...  
Keyword(s):  
Gamma Diversity

scholarly journals Dynamics of gamma diversity and abundance of diurnal butterflies (Lepidoptera, Papilionoformes) in the Nizhny Novgorod Region (Russia) under anthropogenic changes in landscapes over the last hundred years

2021 ◽  
Vol 4 (4) ◽  
pp. 32-41
Author(s):  
Stanislav K. Korb
Keyword(s):  
Russian Regions ◽  
Gamma Diversity ◽  
Natural Conditions ◽  
Boreal Species ◽  
Long Term Monitoring ◽  
Near Future ◽  
First Time ◽  
Term Monitoring ◽  
Nizhny Novgorod Region

The hundred-year dynamics of gamma diversity and butterflies’ abundance have been assessed for the first time in Russia for the Nizhny Novgorod Region. According to analyzed data, we forecast that no significant change in the number of 104 species of butterflies is expected, the number of 33 species in the near future is likely to increase, and the number of 11 species will continue to decline in the near future. A decrease in abundance of 23 steppe and arcto-boreal species is also expected. The reasons for the decrease in the number of species are considered, supported by the long-term monitoring dataset. Extrapolation of our conclusions for Russian regions with similar conditions (Kirov, Ivanovsk, Vladimir, Kostroma, Penza, and Ulyanovsk regions and the Republics of Mari El, Chuvash, and Mordovia), taking into account the natural conditions of these areas, seems applicable and promising.

scholarly journals Do Different Teams Produce Different Results in Long-Term Lichen Biomonitoring?

Diversity ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 43 ◽  
Author(s):  
Giorgio Brunialti ◽  
Luisa Frati ◽  
Cristina Malegori ◽  
Paolo Giordani ◽  
Paola Malaspina
Keyword(s):  
Temporal Variations ◽  
Species Replacement ◽  
Sampling Errors ◽  
Gamma Diversity ◽  
Epiphytic Lichen ◽  
Lichen Diversity ◽  
Data Comparability ◽  
Trends Over Time ◽  
Over Time

Lichen biomonitoring programs focus on temporal variations in epiphytic lichen communities in relation to the effects of atmospheric pollution. As repeated surveys are planned at medium to long term intervals, the alternation of different operators is often possible. This involves the need to consider the effect of non-sampling errors (e.g., observer errors). Here we relate the trends of lichen communities in repeated surveys with the contribution of different teams of specialists involved in sampling. For this reason, lichen diversity data collected in Italy within several ongoing biomonitoring programs have been considered. The variations of components of gamma diversity between the surveys have been related to the composition of the teams of operators. As a major result, the composition of the teams significantly affected data comparability: Similarity (S), Species Replacement (R), and Richness Difference (D) showed significant differences between “same” and “partially” versus “different” teams, with characteristics trends over time. The results suggest a more careful interpretation of temporal variations in biomonitoring studies.

Early Tertiary radiation of marine molluscs and the long-term effects of the Cretaceous-Tertiary extinction

Paleobiology ◽  
1988 ◽  
Vol 14 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Thor A. Hansen
Keyword(s):  
Gulf Coast ◽  
Middle Eocene ◽  
Late Eocene ◽  
Ecological Niches ◽  
Long Term Effects ◽  
Gamma Diversity ◽  
Time Diversity ◽  
Total Diversity ◽  
Radiation Phase

The Cretaceous–Tertiary (K–T) extinction reduced the gamma diversity of molluscs on the U.S. Gulf Coast from over 500 species in the late Maastrichtian to a little over 100 species in the early Danian. Gamma (total) diversity increased in a series of steps that generally tracked temperature, to a high of around 400 species in the late Middle Eocene, at which time diversity declined in the Late Eocene–Oligocene extinctions. The molluscan radiation occurred in at least two distinct phases: 1) an Initial Radiation Phase in which certain families underwent unusually high speciation, apparently filling ecological niches vacated by the extinction, followed by extinction of many of the species in these families in the late Danian; and, 2) a Secondary Radiation Phase where gamma diversity gradually increased and new genera gradually appeared. The fact that the gamma diversity of molluscs did not reach pre-extinction levels before the next extinction in the Late Eocene suggests that molluscan faunas may spend much of their evolutionary time recovering from these extinctions.

Silurian trilobite alpha diversity and the end-Ordovician mass extinction

Paleobiology ◽  
2000 ◽  
Vol 26 (4) ◽  
pp. 625-646 ◽  
Author(s):  
Jonathan M. Adrain ◽  
Stephen R. Westrop ◽  
Brian D. E. Chatterton ◽  
Lars Ramsköld
Keyword(s):  
Alpha Diversity ◽  
Late Ordovician ◽  
Gamma Diversity ◽  
Local Species Richness ◽  
Late Cambrian ◽  
Hierarchical Levels ◽  
Local Species ◽  
Shallow Subtidal ◽  
Long Term Impact

Following the end-Ordovician extinction, global clade diversity of Silurian trilobites dropped to about half of Ordovician levels. Although clade diversity failed to recover, this extinction had surprisingly little long-term impact on the number of trilobite species that occupied local habitats (alpha diversity). A new compilation of data from Laurentia and other continents indicates that Silurian trilobite alpha diversities in all major environments were comparable to those of the Late Cambrian and Ordovician; shallow subtidal diversity reached an all-time high during the Late Ordovician. The profound differences in patterns at local and global levels demonstrate the necessity for a hierarchical approach to analyses of diversity. Factors governing global clade diversity are lodged at hierarchical levels beyond those controlling local species richness and must be sought in studies of between-habitat (beta) or geographic (gamma) diversity.

Beta diversity and similarity of lichen communities as a sign of the times

2018 ◽  
Vol 50 (3) ◽  
pp. 371-383 ◽  
Author(s):  
Paolo GIORDANI ◽  
Giorgio BRUNIALTI ◽  
Marco CALDERISI ◽  
Paola MALASPINA ◽  
Luisa FRATI
Keyword(s):  
Rural Areas ◽  
Beta Diversity ◽  
Urban Areas ◽  
Alpha Diversity ◽  
Atmospheric Pollutants ◽  
Gamma Diversity ◽  
Effective Response ◽  
Epiphytic Lichen ◽  
Lichen Community

AbstractCurrently, change in lichen community structure depends on a combination of several pollutants instead of just one. Consequently, alpha lichen diversity no longer represents an effective response variable for assessing trends in atmospheric pollutants over time. Here we investigated the value of the relationship between alpha diversity and different aspects of gamma diversity (similarity, replacement and differences in richness of species) together with that of beta diversity (calculated as the sum of replacement and difference in richness of species), for assessing complex variations in epiphytic lichen communities in response to a changing pollution scenario. We considered an area subjected to extreme variation in atmospheric pollution in recent decades and explored temporal and spatial aspects of lichen community succession over short-, intermediate- and long-term reference periods. We found that variation in lichen communities for long- and intermediate-term reference periods was strongly dependent on the alpha diversity of single trees at the beginning of the observation period. The occurrence of nitrophytic species, which responded to the decrease in SO2 concentrations, contribute to this trend. The effect of land use was observed only over long observation periods, with trees in urban areas showing less variation than those located in rural areas. In particular, the analysis of similarity, species replacement and differences in richness of tree pairs demonstrated that trends and patterns within lichen communities are neither always nor to the same extent associated with alpha diversity. Our results show that a thorough study of gamma diversity, including beta diversity and similarity, is required to detect changes in air quality in long-term biomonitoring surveys.

scholarly journals Diversity partitioning in Phanerozoic benthic marine communities

2018 ◽  
Vol 116 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Richard Hofmann ◽  
Melanie Tietje ◽  
Martin Aberhan
Keyword(s):  
Ecological Model ◽  
Marine Invertebrates ◽  
Biotic Interactions ◽  
Alpha Diversity ◽  
Gamma Diversity ◽  
Marine Communities ◽  
Long Term Effect ◽  
Beta And Gamma Diversity ◽  
Geological Formations

Biotic interactions such as competition, predation, and niche construction are fundamental drivers of biodiversity at the local scale, yet their long-term effect during earth history remains controversial. To test their role and explore potential limits to biodiversity, we determine within-habitat (alpha), between-habitat (beta), and overall (gamma) diversity of benthic marine invertebrates for Phanerozoic geological formations. We show that an increase in gamma diversity is consistently generated by an increase in alpha diversity throughout the Phanerozoic. Beta diversity drives gamma diversity only at early stages of diversification but remains stationary once a certain gamma level is reached. This mode is prevalent during early- to mid-Paleozoic periods, whereas coupling of beta and gamma diversity becomes increasingly weak toward the recent. Generally, increases in overall biodiversity were accomplished by adding more species to local habitats, and apparently this process never reached saturation during the Phanerozoic. Our results provide general support for an ecological model in which diversification occurs in successive phases of progressing levels of biotic interactions.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

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