scholarly journals Information Across the Ecological Hierarchy

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 949 ◽  
Author(s):  
Ulanowicz
Keyword(s):  
Community Structure ◽  
Conditional Entropy ◽  
Individual Species ◽  
Genomic Information ◽  
Physical Environments ◽  
Level Information ◽  
Ecosystem Level ◽  
Ecological Hierarchy ◽  
And Behavior ◽  
Regular Patterns

The ecosystem is a theatre upon which is presented, in various degrees and at differing scales, a drama of constraint and information vs. disorganization and entropy. Concerning biology, most think immediately of genomic information. It strongly constrains the form and behavior of individual species, but its influence upon community structure is indeterminate. At the community level, information acts as a formal cause behind regular patterns of development. Community structure is an amalgam of information and entropy, and the Gibbs–Boltzmann formula departs from the thermodynamic sense of entropy. It measures only the extreme that entropy might reach if the elements of the system were completely independent. A closer analogy to physical entropy in systems with interactions is the conditional entropy—the amount by which the Shannon measure is reduced after the information in the constraints among elements has been subtracted. Finally, at the whole ecosystem level, in communities that inhabit mostly fixed physical environments (e.g., landscapes or seabeds), the distributions of plants and animals appear to be independent both of causal mechanisms and trophic controls, and assume instead forms that maximize the overall entropy of dispersal.

scholarly journals Idiosyncratic species effects confound size-based predictions of responses to climate change

2012 ◽  
Vol 367 (1605) ◽  
pp. 2971-2978 ◽  
Author(s):  
Marion Twomey ◽  
Eva Brodte ◽  
Ute Jacob ◽  
Ulrich Brose ◽  
Tasman P. Crowe ◽  
...  
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Body Mass ◽  
Marine Species ◽  
Individual Species ◽  
Metabolic Demand ◽  
East Atlantic ◽  
Mass Scaling ◽  
Consumption Rates ◽  
Ecosystem Level

Understanding and predicting the consequences of warming for complex ecosystems and indeed individual species remains a major ecological challenge. Here, we investigated the effect of increased seawater temperatures on the metabolic and consumption rates of five distinct marine species. The experimental species reflected different trophic positions within a typical benthic East Atlantic food web, and included a herbivorous gastropod, a scavenging decapod, a predatory echinoderm, a decapod and a benthic-feeding fish. We examined the metabolism–body mass and consumption–body mass scaling for each species, and assessed changes in their consumption efficiencies. Our results indicate that body mass and temperature effects on metabolism were inconsistent across species and that some species were unable to meet metabolic demand at higher temperatures, thus highlighting the vulnerability of individual species to warming. While body size explains a large proportion of the variation in species' physiological responses to warming, it is clear that idiosyncratic species responses, irrespective of body size, complicate predictions of population and ecosystem level response to future scenarios of climate change.

scholarly journals Variability of macrofauna distribution along a dissipative log-spiral sandy beach in Rio de Janeiro, Southeastern Brazil

2017 ◽  
Vol 81 (1) ◽  
pp. 111 ◽  
Author(s):  
Carlos A.M. Barboza ◽  
Tatiana Cabrini ◽  
Gustavo Mattos ◽  
Viviane Skinner ◽  
Ricardo Cardoso
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Community Structure ◽  
Organic Matter Content ◽  
Principal Component ◽  
Matter Content ◽  
Southeastern Brazil ◽  
Individual Species ◽  
Beach Slope ◽  
Sediment Sorting

Log-spiral beaches display defined physical gradients alongshore. However, the majority of studies focus on the variability of a single population of macrofauna species. We aimed to investigate the variation in species distribution and in community structure along ten transects on a log-spiral beach. Principal component analysis indicated a clear physical gradient alongshore. Redundancy analysis showed that the sheltered end was related to smaller particle sizes, higher organic matter content and high densities of polychaetes. The exposed end was characterized by coarser sand, lower organic matter content and a high presence of crustaceans. Model selection indicated that the “best fit” to explain the variability in the number of individuals included grain size and beach slope. Variability of the polychaete Scolelepis squamata was best explained by grain size, slope and sediment sorting. The best model for the cirolanid Excirolana armata only included sediment sorting. The physical gradient in sediment texture and the beach slope explained more than one-third of the variability in community structure. The physical variables were also correlated with the distribution of the individual species. We showed that the physical gradient on log-spiral coasts may be an important driver of macrofauna variability, even at mesoscales and in dissipative conditions.

Sampling for Studying Context

2016 ◽  
Author(s):  
James G. Gimpel
Keyword(s):  
Target Population ◽  
Social Environments ◽  
Economic Equality ◽  
Sampling Schemes ◽  
Geographic Context ◽  
Physical Environments ◽  
Research Designs ◽  
Media Markets ◽  
And Behavior ◽  
Attitudes And Behavior

Using the example of Ohio and its media markets, this chapter discusses the geographic distribution of respondents resulting from alternative sampling schemes. Traditional survey research designs for gathering information on voter attitudes and behavior usually ignore variability in context in favor of representation of a target population. When sample sizes are large, these polls also provide reasonably accurate estimates for focal subgroups of the electoral population. As the examples here show, conventional polls frequently lack the variations in geographic context likely to matter most to understanding social environments and the interdependence among voters, limiting variation on such continua as urban and rural, economic equality and inequality, occupational differences, exposure to physical environmental conditions, and a variety of other factors that exhibit spatial variation. The chapter calls for more surveys that represent exposure to a broader range of social and physical environments than researchers have produced up to now.

Ecosystem Function

2016 ◽  
Author(s):  
Andrew P. Hendry
Keyword(s):  
Community Structure ◽  
Conceptual Framework ◽  
Time Scales ◽  
Ecosystem Function ◽  
Evolutionary Dynamics ◽  
Relative Strength ◽  
Intraspecific Diversity ◽  
Empirical Methods ◽  
Ecosystem Level ◽  
Key Questions

This chapter explores how the mathematical frameworks, empirical methods, and predictions introduced for community structure can be extended to ecosystem function. Also outlined is an alternative conceptual framework (biological stoichiometry) for evaluating eco-evolutionary dynamics at the ecosystem level. The key questions in this analysis include the importance of intraspecific diversity, the relative strength of the various effects, on what time scales do the effects play out, and to what extent are the effects direct or indirect. The chapter also addresses whether the effects of genotypes decrease toward higher levels of complexity (from phenotypes to communities to ecosystems), and to what extent feedbacks are evident-traits influence ecosystems which then influence traits.

scholarly journals Co-variation in soil biodiversity and biogeochemistry in northern and southern Victoria Land, Antarctica

2006 ◽  
Vol 18 (4) ◽  
pp. 535-548 ◽  
Author(s):  
J.E. Barrett ◽  
R.A. Virginia ◽  
D.H. Wall ◽  
S.C. Cary ◽  
B.J. Adams ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Diversity ◽  
Habitat Suitability ◽  
Dna Analysis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Habitat Preferences ◽  
Individual Species ◽  
Species Variation ◽  
Soil Biodiversity ◽  
Victoria Land

Data from six sites in Victoria Land (72–77°S) investigating co-variation in soil communities (microbial and invertebrate) with biogeochemical properties showthe influence of soil properties on habitat suitability varied among local landscapes as well as across climate gradients. Species richness of metazoan invertebrates (Nematoda, Tardigrada and Rotifera) was similar to previous descriptions in this region, though identification of three cryptic nematode species of Eudorylaimus through DNA analysis contributed to the understanding of controls over habitat preferences for individual species. Denaturing Gradient Gel Electrophoresis profiles revealed unexpectedly high diversity of bacteria. Distribution of distinct bacterial communities was associated with specific sites in northern and southern Victoria Land, as was the distribution of nematode and tardigrade species. Variation in soil metazoan communities was related to differences in soil organic matter, while bacterial diversity and community structure were not strongly correlated with any single soil property. There were no apparent correlations between metazoan and bacterial diversity, suggesting that controls over distribution and habitat suitability are different for bacterial and metazoan communities. Our results imply that top-down controls over bacterial diversity mediated by their metazoan consumers are not significant determinants of bacterial community structure and biomass in these ecosystems.

Cancer patients: Assessing awareness, attitudes and claimed behavior around key decision points upon being diagnosed.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e23052-e23052
Author(s):  
Kerri Lehrhaupt ◽  
Lori Tauber Marcus ◽  
Anne Quinn Young ◽  
Jenny Isaacson ◽  
Marc Hurlbert ◽  
...  
Keyword(s):  
Precision Medicine ◽  
Online Survey ◽  
Inclusion Criteria ◽  
Genomic Information ◽  
The Past ◽  
Decision Points ◽  
The Us ◽  
Specific Cancer ◽  
The Right ◽  
And Behavior

e23052 Background: As precision medicine becomes increasingly important in oncology, patients need to be educated on making decisions at diagnosis to optimize their outcomes. The HBS Kraft Precision Medicine Accelerator is working with national cancer organizations to understand and address gaps in knowledge and action. Informed by prior patient and physician research, the Accelerator developed the Right Track framework, which addresses the unmet educational needs of patients as they navigate their journey. Methods: Participants with newly diagnosed cancer were recruited by the 5 participating foundations from their databases of affiliated patients (MMRF: n = 63, PanCAN: n = 202, LUNGevity: n = 51, PCF: n = 71, MBC Alliance: n = 66). Inclusion criteria included currently living in the US, 25 years or older, diagnosed with a qualifying cancer in the past 12 months (past 18 months for LUNGevity), self-reported as being at least somewhat knowledgeable in their disease, and self-reported as having some input in treatment decisions. The study was conducted by Kantar Health and sponsored by the HBS Kraft Precision Medicine Accelerator. The fielding was conducted in October 2018. Potential respondents were e-mailed an invitation to complete a 20-minute online survey. Potential respondents were also exposed to an invitation via social media from the participating study sponsors. The respondents were asked a series of customized questions that assessed their awareness and behavior on items within each of the four pillars of the Right Track framework. Results: Descriptive analyses were conducted on each of the four pillars (Right Team, Right Tests, Right Treatment, Sharing at Every Step) and it was found that educational gaps exist across all five cancers. Patients require guidance on selecting a knowledgeable team and facility, understanding their specific cancer sub-type and genomic information, participation in clinical trials and the importance of sharing their data. Conclusions: There is a strong need for patient advocacy foundations to work as unbiased, patient-focused organizations, such that they are well-positioned to help close these knowledge gaps.

Effects of Pleistocene environmental changes on the distribution and community structure of the mammalian fauna of Mexico

2010 ◽  
Vol 73 (3) ◽  
pp. 464-473 ◽  
Author(s):  
Gerardo Ceballos ◽  
Joaquín Arroyo-Cabrales ◽  
Eduardo Ponce
Keyword(s):  
Community Structure ◽  
Central America ◽  
Late Pleistocene ◽  
Environmental Changes ◽  
Individual Species ◽  
Mammalian Fauna ◽  
Sierra Madre ◽  
Central United States ◽  
Mammalian Faunas ◽  
Eastern Usa

Biological communities in Mexico experienced profound changes in species composition and structure as a consequence of the environmental fluctuations during the Pleistocene. Based on the recent and fossil Mexican mammal checklists, we determine the distribution, composition, diversity, and community structure of late Pleistocene mammalian faunas, and analyze extinction patterns and response of individual species to environmental changes. We conclude that (1) differential extinctions occurred at family, genus, and species level, with a major impact on species heavier than 100 kg, including the extinction all proboscideans and several ruminants; (2) Pleistocene mammal communities in Mexico were more diverse than recent ones; and (3) the current assemblages of species are relatively young. Furthermore, Pleistocene relicts support the presence of biogeographic corridors; important refugia existed as well as centers of speciation in isolated regions. We identified seven corridors: eastern USA–Sierra Madre Oriental corridor, Rocky Mountains–Sierra Madre Occidental corridor, Central United States–Northern Mexico corridor, Transvolcanic Belt–Sierra Madre del Sur corridor, western USA–Baja California corridor, Tamaulipas–Central America gulf lowlands corridor, and Sonora–Central America Pacific lowlands corridor. Our study suggests that present mammalian assemblages are very different than the ones in the late Pleistocene.

Variations in the community structure of biofilm-dwelling protozoa at different depths in coastal waters of the Yellow Sea, northern China

2017 ◽  
Vol 99 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Mamun Abdullah Al ◽  
Yangyang Gao ◽  
Guangjian Xu ◽  
Zheng Wang ◽  
Henglong Xu ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Coastal Waters ◽  
Yellow Sea ◽  
Northern China ◽  
Marine Ecosystems ◽  
Artificial Substrates ◽  
The Yellow Sea ◽  
Individual Species ◽  
Protozoan Community

Biofilm-dwelling protozoa are a primary component of microbiota and play important roles in the functioning of microbial food webs such as the mediation of carbon and energy flux from plankton to benthos in marine ecosystems. To demonstrate the vertical pattern of the protozoan communities, a 1-month baseline survey was carried out in coastal waters of the Yellow Sea, northern China. A total of 40 samples were collected using glass slides as artificial substrates at four depths: 1, 2, 3.5 and 5 m. A total of 50 species were identified, comprising seven dominant and eight commonly distributed species. Species richness and individual species abundances showed a clear decreasing trend down the water column from 1 to 5 m, although the former peaked at a depth of 2 m. Multivariate approaches revealed that protozoan community structure differed significantly among the four depths, except for those at 2 and 3.5 m. Maximum values of species richness, diversity and evenness generally decreased with depth although they peaked at either 2 or 3.5 m. These results suggest that water depth may significantly shape the community patterns of biofilm-dwelling protozoa in marine ecosystems.

scholarly journals Regularity underlies erratic population abundances in marine ecosystems

2015 ◽  
Vol 12 (107) ◽  
pp. 20150235 ◽  
Author(s):  
Jie Sun ◽  
Sean P. Cornelius ◽  
John Janssen ◽  
Kimberly A. Gray ◽  
Adilson E. Motter
Keyword(s):  
Extinction Risk ◽  
Single Species ◽  
Marine Species ◽  
Individual Species ◽  
Demographic Stochasticity ◽  
Key Factor ◽  
Species Population ◽  
Ecosystem Level ◽  
Management Approaches ◽  
The Individual

The abundance of a species' population in an ecosystem is rarely stationary, often exhibiting large fluctuations over time. Using historical data on marine species, we show that the year-to-year fluctuations of population growth rate obey a well-defined double-exponential (Laplace) distribution. This striking regularity allows us to devise a stochastic model despite seemingly irregular variations in population abundances. The model identifies the effect of reduced growth at low population density as a key factor missed in current approaches of population variability analysis and without which extinction risks are severely underestimated. The model also allows us to separate the effect of demographic stochasticity and show that single-species growth rates are dominantly determined by stochasticity common to all species. This dominance—and the implications it has for interspecies correlations, including co-extinctions—emphasizes the need for ecosystem-level management approaches to reduce the extinction risk of the individual species themselves.

scholarly journals Climate change, biotic interactions and ecosystem services

2010 ◽  
Vol 365 (1549) ◽  
pp. 2013-2018 ◽  
Author(s):  
José M. Montoya ◽  
Dave Raffaelli
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Current Knowledge ◽  
Good Condition ◽  
Biotic Interactions ◽  
Population Level ◽  
Individual Species ◽  
Ample Evidence ◽  
Starting Point ◽  
Ecosystem Level

Climate change is real. The wrangling debates are over, and we now need to move onto a predictive ecology that will allow managers of landscapes and policy makers to adapt to the likely changes in biodiversity over the coming decades. There is ample evidence that ecological responses are already occurring at the individual species (population) level. The challenge is how to synthesize the growing list of such observations with a coherent body of theory that will enable us to predict where and when changes will occur, what the consequences might be for the conservation and sustainable use of biodiversity and what we might do practically in order to maintain those systems in as good condition as possible. It is thus necessary to investigate the effects of climate change at the ecosystem level and to consider novel emergent ecosystems composed of new species assemblages arising from differential rates of range shifts of species. Here, we present current knowledge on the effects of climate change on biotic interactions and ecosystem services supply, and summarize the papers included in this volume. We discuss how resilient ecosystems are in the face of the multiple components that characterize climate change, and suggest which current ecological theories may be used as a starting point to predict ecosystem-level effects of climate change.

Sign in / Sign up

Export Citation Format

Share Document