scholarly journals The First Age of Reptiles? Comparing Reptile and Synapsid Diversity, and the Influence of Lagerstätten, During the Carboniferous and Early Permian

2021 ◽  
Vol 9 ◽  
Author(s):  
Neil Brocklehurst
Keyword(s):  
Spatial Scales ◽  
Alpha Diversity ◽  
Terrestrial Ecosystems ◽  
Sampling Bias ◽  
Early Permian ◽  
Diversity Patterns ◽  
Local Species Richness ◽  
True Diversity ◽  
Traditional Taxonomy ◽  
Amniote Phylogeny

Terrestrial ecosystems during the Pennsylvanian (late Carboniferous) and Cisuralian (early Permian) are usually described in the literature as being dominated by synapsids, the mammal-line amniotes. The pelycosaurs (a paraphyletic grouping of synapsid families) have been considered more speciose, abundant, and ecologically diverse than contemporary reptile-line amniotes. However, this dominance has never been subjected to quantitative testing accounting for sampling bias. Moreover, in recent years the amniote phylogeny has undergone numerous revisions, with suggestions that varanopids and recumbirostran microsaurs fall within reptiles, and that diadectomorphs may be pelycosaurian-grade synapsids. An examination of local species richness (alpha diversity) of synapsids and reptiles during the Pennsylvanian and Cisuralian at different spatial scales shows that these taxonomic revisions have substantial impacts on relative diversity patterns of synapsids and reptiles. Synapsids are only found to be consistently more diverse through the early Permian when using the “traditional” taxonomy. The recent taxonomic updates produce diversity estimates where reptile diversity is consistent with, or in some cases higher than that of synapsids. Moreover, biases in preservation may affect patterns. Where preservation favors smaller vertebrates, e.g., Richards Spur, South Grandfield, reptiles overwhelmingly dominate. If smaller vertebrates are expected to make up the bulk of amniote diversity, as they do in the present day, such lagerstätten may be more representative of true diversity patterns. Therefore, the dominance of pelycosaurs during this interval should be reconsidered, and this interval may be considered the First Age of Reptiles.

scholarly journals On what scales can GOSAT flux inversions constrain anomalies in terrestrial ecosystems?

2019 ◽  
Author(s):  
Brendan Byrne ◽  
Dylan B. A. Jones ◽  
Kimberly Strong ◽  
Saroja M. Polavarapu ◽  
Anna B. Harper ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Net Ecosystem Exchange ◽  
Terrestrial Ecosystems ◽  
Atmospheric Co2 ◽  
Strong Correlations ◽  
Climate Anomalies ◽  
Temperature And Precipitation ◽  
The Tropics ◽  
Emergent Constraint ◽  
The Impact

Abstract. Interannual variations in temperature and precipitation impact the carbon balance of terrestrial ecosystems, leaving an imprint in atmospheric CO2. Quantifying the impact of climate anomalies on the net ecosystem exchange (NEE) of terrestrial ecosystems can provide a constraint to evaluate terrestrial biosphere models against, and may provide an emergent constraint on the response of terrestrial ecosystems to climate change. We investigate the spatial scales over which interannual variability in NEE can be constrained using atmospheric CO2 observations from the Greenhouse Gases Observing Satellite (GOSAT). NEE anomalies are calculated by performing a series of inversion analyses using the GEOS-Chem model to assimilate GOSAT observations. Monthly NEE anomalies are compared to proxies, variables which are associated with anomalies in the terrestrial carbon cycle, and to upscaled NEE estimates from FLUXCOM. Strong agreement is found in the timing of anomalies in the GOSAT flux inversions with soil temperature and FLUXCOM. Strong correlations are obtained (P  RNINO3.4) in the tropics on continental and larger scales, and in the northern extratropics on sub-continental scales during the summer (R2 ≥ 0.49). These results, in addition to a series of observing system simulation experiments that were conducted, provide evidence that GOSAT flux inversions can isolate anomalies in NEE on continental and larger scales. However, in both the tropics and northern extratropics, the agreement between the inversions and the proxies/FLUXCOM is sensitive to the flux inversion configuration. Our results suggest that regional scales are likely the minimum scales that can be resolved in the tropics using GOSAT observations, but obtaining robust NEE anomaly estimates on these scales may be difficult.

scholarly journals Soil CO<sub>2</sub> efflux errors are lognormally distributed – implications and guidance

2020 ◽  
Vol 9 (1) ◽  
pp. 239-254
Author(s):  
Thomas Wutzler ◽  
Oscar Perez-Priego ◽  
Kendalynn Morris ◽  
Tarek S. El-Madany ◽  
Mirco Migliavacca
Keyword(s):  
Random Error ◽  
Carbon Sink ◽  
Spatial Scales ◽  
Good Practice ◽  
Terrestrial Ecosystems ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Value Differences ◽  
Distributional Assumptions

Abstract. Soil CO2 efflux is the second-largest carbon flux in terrestrial ecosystems. Its feedback to climate determines model predictions of the land carbon sink, which is crucial to understanding the future of the earth system. For understanding and quantification, however, observations by the most widely applied chamber measurement method need to be aggregated to larger temporal and spatial scales. The aggregation is hampered by random error that is characterized by occasionally large fluxes and variance heterogeneity that is not properly accounted for under the typical assumption of normally distributed fluxes. Therefore, we explored the effect of different distributional assumptions on the aggregated fluxes. We tested the alternative assumption of lognormally distributed random error in observed fluxes by aggregating 1 year of data of four neighboring automatic chambers at a Mediterranean savanna-type site. With the lognormal assumption, problems with error structure diminished, and more reasonable prediction intervals were obtained. While the differences between distributional assumptions diminished when aggregating data of single chambers to an annual value, differences were important on short timescales and were especially pronounced when aggregating across chambers to plot level. Hence we recommend as a good practice that researchers report plot-level fluxes with uncertainties based on the lognormal assumption. Model data integration studies should compare predictions and observations of soil CO2 efflux on a log scale. This study provides methodology and guidance that will improve the analysis of soil CO2 efflux observations and hence improve understanding of soil carbon cycling and climate feedbacks.

Discovery of coprolites in an Early Permian fern mesophyll

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
WEI-MING ZHOU ◽  
MING-LI WAN ◽  
JOSEF PŠENIČKA ◽  
JUN WANG
Keyword(s):  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Functional Feeding Groups ◽  
Early Permian ◽  
Plant Organs ◽  
Feeding Groups ◽  
Fossil Records

Plants and arthropods interact with each other and constitute an important part of the modern terrestrial ecosystem (Schoonhoven et al., 2005). Historically, fossil records of plant-arthropod interactions have been well documented in Paleozoic terrestrial ecosystems, which were evidenced by large coprolites containing various plant fragments (e.g., Salter et al., 2012), small larvae and coprolites remained in plant organs (e.g., Feng et al., 2017), and diverse functional feeding groups discovered on plant stems, rachises, roots, leaves and fertile organs (e.g., Liu et al., 2020).

scholarly journals Unimodal Relationships of Understory Alpha and Beta Diversity along Chronosequence in Coppiced and Unmanaged Beech Forests

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 101 ◽  
Author(s):  
Sándor Bartha ◽  
Roberto Canullo ◽  
Stefano Chelli ◽  
Giandiego Campetella
Keyword(s):  
Beta Diversity ◽  
Management Practices ◽  
Multiple Scales ◽  
Forest Succession ◽  
Spatial Scales ◽  
Alpha Diversity ◽  
Structural Diversity ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
Coppice Management

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 × 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray–Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value.

scholarly journals Ozone affects plant, insect, and soil microbial communities: A threat to terrestrial ecosystems and biodiversity

2020 ◽  
Vol 6 (33) ◽  
pp. eabc1176 ◽  
Author(s):  
Evgenios Agathokleous ◽  
Zhaozhong Feng ◽  
Elina Oksanen ◽  
Pierre Sicard ◽  
Qi Wang ◽  
...  
Keyword(s):  
Plant Competition ◽  
Root Exudation ◽  
Soil Microbial Communities ◽  
Alpha Diversity ◽  
Terrestrial Ecosystems ◽  
Insect Communities ◽  
Soil Microbial ◽  
Plant Soil ◽  
Equatorial Africa ◽  
Insect Interactions

Elevated tropospheric ozone concentrations induce adverse effects in plants. We reviewed how ozone affects (i) the composition and diversity of plant communities by affecting key physiological traits; (ii) foliar chemistry and the emission of volatiles, thereby affecting plant-plant competition, plant-insect interactions, and the composition of insect communities; and (iii) plant-soil-microbe interactions and the composition of soil communities by disrupting plant litterfall and altering root exudation, soil enzymatic activities, decomposition, and nutrient cycling. The community composition of soil microbes is consequently changed, and alpha diversity is often reduced. The effects depend on the environment and vary across space and time. We suggest that Atlantic islands in the Northern Hemisphere, the Mediterranean Basin, equatorial Africa, Ethiopia, the Indian coastline, the Himalayan region, southern Asia, and Japan have high endemic richness at high ozone risk by 2100.

Environmental correlates of herpetofaunal diversity in Costa Rica

2010 ◽  
Vol 26 (5) ◽  
pp. 521-531 ◽  
Author(s):  
David Laurencio ◽  
Lee A. Fitzgerald
Keyword(s):  
Costa Rica ◽  
Species Diversity ◽  
Beta Diversity ◽  
Geographic Distance ◽  
Alpha Diversity ◽  
High Elevation ◽  
Diversity Patterns ◽  
Regional Diversity ◽  
Environmental Correlates ◽  
High Elevation Site

Abstract:Disentangling local and historical factors that determine species diversity patterns at multiple spatial scales is fundamental to elucidating processes that govern ecological communities. Here we investigated how environmental correlates may influence diversity at local and regional scales. Primarily utilizing published species lists, amphibian and reptile alpha and beta diversity were assessed at 17 well-surveyed sites distributed among ecoregions throughout Costa Rica. The degree to which regional species diversity patterns were related to environmental variables and geographic distance was determined using Canonical Correspondence Analysis and Mantel tests. Amphibian alpha diversity was highest in lowland Pacific sites (mean = 43.3 species) and lowest at the high elevation site (9 species). Reptile alpha diversity values were high for both lowland Atlantic (mean = 69.5 species) and lowland Pacific (mean = 67 species) sites and lowest for the high elevation site (8 species). We found high species turnover between local sites and ecoregions, demonstrating the importance of beta diversity in the determination of regional diversity. For both amphibians and reptiles, beta diversity was highest between the high-elevation site and all others, and lowest among lowland sites within the same ecoregion. The effect of geographic distance on beta diversity was minor. Ecologically significant climatic variables related to rain, temperature, sunshine and insolation were found to be important determinants of local and regional diversity for both amphibians and reptiles in Costa Rica.

Fire Ecology

Ecology ◽  
2012 ◽  
Author(s):  
John Parminter
Keyword(s):  
Fire Ecology ◽  
Fire History ◽  
Spatial Scales ◽  
Natural Disturbance ◽  
Terrestrial Ecosystems ◽  
Fire Regimes ◽  
Fire Effects ◽  
Forest Harvesting ◽  
Natural Disturbances ◽  
Wilderness Areas

Abiotic natural disturbance agents include wildfire, wind, landslides, snow avalanches, volcanoes, flooding, and other weather-related phenomena. Fire is of particular interest because of its antiquity, its natural role in many terrestrial ecosystems, its long-term use by humans to modify vegetation, and its potentially serious threat to life and property. Fire ecology is the art and science of understanding natural and human fire history and fire effects on the environment, species, ecosystems, and landscapes. This knowledge aids the development of fire and ecosystem management plans and activities. Fire history is determined by a number of techniques that use available physical or cultural evidence to examine particular temporal and spatial scales. Fire effects on the environment and organisms are determined by observation and experimentation, but the findings are variable and often contradictory. Fire regimes are used to characterize the role of fire in specific ecosystems and can help guide ecosystem restoration activities. Attitudes toward fire have evolved over time, as good and bad experiences combined with improved scientific understanding to influence our perspectives. Natural disturbances came to be viewed as integral parts of ecosystems rather than external perturbations. We now strive to allow fire to maintain its natural role in wilderness areas and parks and also to emulate natural disturbances, such as fire, when designing forest harvesting operations. This article focuses on how and what we know about fire’s history, its effects on different components of the environment, its role in specific vegetation types, and its relationship with human culture.

Diversity patterns among early gastropods: contrasting taxonomic and phylogenetic descriptions

Paleobiology ◽  
1995 ◽  
Vol 21 (4) ◽  
pp. 410-439 ◽  
Author(s):  
Peter J. Wagner
Keyword(s):  
Phylogenetic Diversity ◽  
Logistic Growth ◽  
Test Case ◽  
Data Sets ◽  
Diversity Patterns ◽  
Phylogenetic Data ◽  
Systematic Philosophy ◽  
Generic Data ◽  
Traditional Taxonomy ◽  
Diversity Studies

Paleobiologists have used taxonomic data for several types of diversity studies. Some systematists have charged that this practice obfuscates actual historical patterns of clades because many traditionally defined higher taxa are not monophyletic. Some have questioned whether ranked taxa ever represent comparable units, even when monophyletic. This study contrasts diversity patterns implied by phylogenetic estimates with those implied by ranked taxa. Early Paleozoic gastropods are useful as a test case because their generic taxonomy does not reflect the phylogenetic systematic philosophy, and fewer than one third of the genera represent monophyletic clades. Phylogenetic diversity is described in two ways: (1) numbers of lineages (i.e., observed plus phylogenetically implied “ghost lineages”), and (2) numbers of monophyla (i.e., clades whose sister taxa are other clades rather than species). “Monophyla” as tallied here are monophyletic relative to their contemporaries and older clades; however, they can be paraphyletic relative to “future” monophyla. Phylogenetic diversity is tallied with both maximum and minimum “ghost lineage” interpolations in order to reflect different possible speciation patterns and timings of speciation. Phylogenetic diversity as implied by a stricter cladistic criterion (i.e., taxa that are monophyletic relative to their contemporaries, older taxa and younger taxa) is discussed also.First differences between substage-to-substage standing diversities reveal significant congruence between generic data and both types of phylogenetic data. Taxonomic and phylogenetic data imply a major extinction event at the end of the Ordovician, although the phylogenetic data suggest greater extinction levels than do the taxonomic data. Both data sets also suggest diversity-dependent diversification reminiscent of logistic growth, which is the pattern predicted if one or a few major ecologic factors were constraining the diversification of gastropods. However, diversity described by strict Hennigian taxa is not highly congruent with diversity as described by either lineages or monophyla. Comparing subclade dynamics requires extensive redefinition of traditional orders, but lineages, monophyla and genera all suggest that the two major subclades had different logistic diversification patterns, with one (“murchisonioids”) having a higher K than the other (“euomphaloids”). The concern that phylogenetic and taxonomic data might imply very different evolutionary histories is not borne out by gastropods, despite the nonphylogenetic nature of their traditional taxonomy.

scholarly journals Small Things Matter: The Value of Rapid Biodiversity Surveys to Understanding Local Bird Diversity Patterns in Southcentral Mindanao, Philippines

2019 ◽  
Vol 12 ◽  
pp. 194008291986948 ◽  
Author(s):  
Krizler Cejuela Tanalgo ◽  
Marion John Michael M. Achondo ◽  
Alice C. Hughes
Keyword(s):  
Conservation Planning ◽  
Ecosystem Health ◽  
Rapid Assessment ◽  
Terrestrial Ecosystems ◽  
Ecological Indicators ◽  
Bird Diversity ◽  
Habitat Types ◽  
Diversity Patterns ◽  
Small Things ◽  
Regional Conservation

Rapid assessment biodiversity surveys are usually employed when resources or time is limited. In terrestrial ecosystems, birds are important ecological indicators of ecosystem health. Our study used rapid inventories to show that species differ across habitat types; species richness and rarity were higher in pristine habitats (native and restored areas) while nonprotected habitats (e.g., plantations and orchards) mainly had common and nonendemic species. Our findings demonstrate the importance of collective local biodiversity studies in elucidating species diversity patterns, though is equally important to bolster regional conservation prioritization. We hope that our findings will benefit future decision-making for sustainable development and conservation planning.

Comparing palynological abundance and diversity: implications for biotic replacement during the Cretaceous angiosperm radiation

Paleobiology ◽  
1999 ◽  
Vol 25 (3) ◽  
pp. 305-340 ◽  
Author(s):  
Richard Lupia ◽  
Scott Lidgard ◽  
Peter R. Crane
Keyword(s):  
Spatial Scales ◽  
Sampling Bias ◽  
Taxonomic Diversity ◽  
Detailed Examination ◽  
Northern Region ◽  
Data Sets ◽  
Floristic Diversity ◽  
Apparent Contradiction ◽  
Vegetational Change ◽  
Abundance And Diversity

The Cretaceous radiation of angiosperms initiated a major reorganization of terrestrial plant communities as dominance by pteridophytic and gymnospermic groups eventually gave way to dominance by angiosperms. Previously, patterns of biotic replacement have been assessed using measures based on taxonomic diversity data. However, using measures of both abundance and diversity to investigate replacement patterns provides more information about macroecological change in the fossil record than either can provide alone. Analyses of an updated and expanded database of North American palynological samples from Cretaceous sediments document a rapid increase in angiosperm diversity and abundance within individual fossil palynofloras (representing local/subregional vegetation). New analyses of floristic diversity patterns support previous results and indicate that the decline of free-sporing plants is more pronounced than the decline of gymnosperms. In contrast, analyses of abundance data appear to show that the decline of gymnosperms is far more pronounced than the decline of free-sporing plants. Detailed examination of both data sets segregated by paleolatitude shows that this apparent contradiction reflects biogeographical differences in the patterns of vegetational change (e.g., free-sporing plants declined in abundance at lower latitudes) as well as sampling bias (e.g., greater sampling in the northern region in the Late Cretaceous). Analyses accounting for these biases support the conclusion that as angiosperms radiated, free-sporing plants rather than gymnosperms (in this case, mainly conifers) experienced the most pronounced decline. A thorough understanding of the Cretaceous radiation of angiosperms will require both abundance and diversity data. It also will require expanding the analyses presented here into other geographic regions as well as sampling more completely at all spatial scales.

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