scholarly journals mobsim: An R package for the simulation and measurement of biodiversity across spatial scales

2017 ◽  
Author(s):  
Felix May ◽  
Katharina Gerstner ◽  
Dan McGlinn ◽  
Xiao Xiao ◽  
Jonathan M. Chase
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Spatial Scales ◽  
R Package ◽  
Spatial Aggregation ◽  
Abundance Distribution ◽  
Real World Data ◽  
Ecological Processes ◽  
Biodiversity Patterns ◽  
Richness Estimators

Abstract1. Estimating biodiversity and its changes in space and time poses serious methodological challenges. First, there has been a long debate on how to quantify biodiversity, and second, measurements of biodiversity change are scale-dependent. Therefore comparisons of biodiversity metrics between communities are ideally carried out across scales. Simulation can be used to study the utility of biodiversity metrics across scales, but most approaches are system specific and plagued by large parameter spaces and therefore cumbersome to use and interpret. However, realistic spatial biodiversity patterns can be generated without reference to ecological processes, which suggests a simple simulation framework could provide an important tool for ecologists.2. Here, we present the R package mobsim that allows users to simulate the abundances and the spatial distribution of individuals of different species. Users can define key properties of communities, including the total numbers of individuals and species, the relative abundance distribution, and the degree of spatial aggregation. Furthermore, the package provides functions that derive biodiversity patterns from simulated communities, or from observed data, as well as functions that simulate different sampling designs.3. We show several example applications of the package. First, we illustrate how species rarefaction and accumulation curves can be used to disentangle changes in the fundamental biodiversity components: (i) total abundance, (ii) relative abundance distribution, (iii) and species aggregation. Second, we demonstrate how mobsim can be used to assess the performance of species-richness estimators. The latter indicates how spatial aggregation challenges classical non-spatial species-richness estimators.4. mobsim allows the simulation and analysis of a large range of biodiversity scenarios and sampling designs in an efficient and comprehensive way. The simplicity and control provided by the package can also make it a useful didactic tool. The combination of controlled simulations and their analysis will facilitate a more rigorous interpretation of real world data that exhibit sampling effects and scale-dependence.

scholarly journals A relationship between species richness and evenness that depends on specific relative abundance distribution

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4951
Author(s):  
Qiang Su
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Strong Correlation ◽  
Statistical Analyses ◽  
Abundance Distribution ◽  
Raw Data ◽  
Fractal Distribution ◽  
The Relationship ◽  
Rank Abundance

Although many ecologists focus on the relationship between species richness (S) and evenness (E), conflicts between observation and theory are difficult to reconcile. Empirical S–E relationships were not consistent, while relationships show strong correlation between S and E. Since E essentially depended on the relative abundance distribution (RAD), the hypothesis of this paper was that the S–E relationship should be determined by RAD. Theoretical S–E relationships for various RADs have already been reported, but they were rarely assessed by the raw data. This study constructed S–E relationships for a specific RAD, which indicated that if the community had a fractal distribution of rank abundance, E would decrease with S, and the S–E relationship would be unique for a given RAD. Such theoretical expectations were supported by three datasets with 82 samples, which suggested that the S–E relationship were controlled by RAD and inconsistent S–E relationships in statistical analyses could be accounted for by the variation of underlying RAD model between communities. From the perspective of RAD, it could be too early to split the diversity into S and E only based on the S–E relationship in statistical analyses.

Aquatic and semi aquatic Hemiptera community of Sonebeel, the largest wetland of Assam, northeastern India

2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta
Keyword(s):  
Species Richness ◽  
Pest Control ◽  
Relative Abundance ◽  
Species Distribution ◽  
Diversity Indices ◽  
Environmental Data ◽  
Northeastern India ◽  
Ecological Roles

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 

scholarly journals Complex community responses underpin biodiversity change following invasion

2021 ◽  
Author(s):  
Alessandra R. Kortz ◽  
Anne E. Magurran
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Spatial Scales ◽  
Species Abundance ◽  
Ecological Systems ◽  
Multi Scale ◽  
Mechanistic Approach ◽  
Α Diversity ◽  
Biodiversity Change ◽  
Insight Into

AbstractHow do invasive species change native biodiversity? One reason why this long-standing question remains challenging to answer could be because the main focus of the invasion literature has been on shifts in species richness (a measure of α-diversity). As the underlying components of community structure—intraspecific aggregation, interspecific density and the species abundance distribution (SAD)—are potentially impacted in different ways during invasion, trends in species richness provide only limited insight into the mechanisms leading to biodiversity change. In addition, these impacts can be manifested in distinct ways at different spatial scales. Here we take advantage of the new Measurement of Biodiversity (MoB) framework to reanalyse data collected in an invasion front in the Brazilian Cerrado biodiversity hotspot. We show that, by using the MoB multi-scale approach, we are able to link reductions in species richness in invaded sites to restructuring in the SAD. This restructuring takes the form of lower evenness in sites invaded by pines relative to sites without pines. Shifts in aggregation also occur. There is a clear signature of spatial scale in biodiversity change linked to the presence of an invasive species. These results demonstrate how the MoB approach can play an important role in helping invasion ecologists, field biologists and conservation managers move towards a more mechanistic approach to detecting and interpreting changes in ecological systems following invasion.

Catalogue of aquatic Oligochaeta (Annelida: Clitellata) of Montenegro, exclusive of Naidinae and Pristininae

Zootaxa ◽  
2011 ◽  
Vol 2985 (1) ◽  
pp. 1
Author(s):  
DANIJELA ŠUNDIĆ ◽  
BRANKO M. RADUJKOVIĆ ◽  
JASMINA KRPO–ĆETKOVIĆ
Keyword(s):  
Species Richness ◽  
Black Sea ◽  
Adriatic Sea ◽  
First Record ◽  
Aquatic Oligochaeta ◽  
The Black Sea ◽  
Drainage Basins ◽  
Aquatic Oligochaete ◽  
Balkan Region ◽  
Richness Estimators

The aquatic oligochaete fauna of Montenegro was recently studied in order to improve the knowledge of this group in the Balkan region. This study was carried out on sediments collected from 70 sampling sites (the Black Sea and the Adriatic Sea drainage basins) during three years (2005–2008). Forty-one species were identified, from seven following families: Naididae, Enchytraeidae, Haplotaxidae, Lumbriculidae, Lumbricidae, Criodrilidae and Branchiobdellidae (exclusive of Naidinae and Pristininae). Sixteen of them represent first record for the Montenegrin oligochaete fauna: Embolocephalus velutinus, Ilyodrilus templetoni, Psammoryctides deserticola, Spirosperma ferox, Tubifex ignotus, Bathydrilus adriaticus, Bothrioneurum vejdovskyanum, Rhyacodrilus coccineus, Cernosvitoviella atrata, Enchytraeus buchholzi, Mesenchytraeus armatus, Haplotaxis gordioides, Rhynchelmis limosella, Stylodrilus heringianus, Tatriella slovenica and Trichodrilus strandi. The list of species from the subfamilies Naidinae and Pristininae was published previously (Šundić et al. 2011), and it comprises 36 species. Altogether, the present study and literature data show that Montenegrin aquatic oligochaete fauna consists of 77 species. Concerning similarity, values of Jaccard’s index are the highest between Montenegrin and Serbian oligochaete fauna (57 %), and the lowest between Montenegrin and Albanian oligochaete fauna (27.77 %). Species richness estimators (Mao Tau, Uniques Mean, Chao 1, Chao 2, Jack 1, Jack 2, Bootstrap, ACE and ICE) indicate that findings of new oligochaete species in Montenegro are expected.

scholarly journals Structure of three subtropical bat assemblages (Chiroptera) in the Andean rainforests of Argentina

Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Common Species ◽  
Guild Structure ◽  
Trophic Guild ◽  
Long Tail ◽  
Mist Net ◽  
Yungas Forests

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus

scholarly journals Altitudinal Vascular Plant Richness and Climate Change in the Alpine Zone of the Lefka Ori, Crete

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
George Kazakis ◽  
Dany Ghosn ◽  
Ilektra Remoundou ◽  
Panagiotis Nyktas ◽  
Michael A. Talias ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Spatial Scales ◽  
Vascular Plant ◽  
Monitoring Network ◽  
Mediterranean Area ◽  
Mean Annual Temperature ◽  
High Mountain ◽  
Species Loss ◽  
Total Species Richness

High mountain zones in the Mediterranean area are considered more vulnerable in comparison to lower altitudes zones. Lefka Ori massif, a global biodiversity hotspot on the island of Crete is part of the Global Observation Research Initiative in Alpine Environments (GLORIA) monitoring network. The paper examines species and vegetation changes with respect to climate and altitude over a seven-year period (2001–2008) at a range of spatial scales (10 m Summit Area Section-SAS, 5 m SAS, 1 m2) using the GLORIA protocol in a re-survey of four mountain summits (1664 m–2339 m). The absolute species loss between 2001–2008 was 4, among which were 2 endemics. At the scale of individual summits, the highest changes were recorded at the lower summits with absolute species loss 4 in both cases. Paired t-tests for the total species richness at 1 m2 between 2001–2008, showed no significant differences. No significant differences were found at the individual summit level neither at the 5 m SAS or the 10 m SAS. Time series analysis reveals that soil mean annual temperature is increasing at all summits. Linear regressions with the climatic variables show a positive effect on species richness at the 5 m and 10 m SAS as well as species changes at the 5 m SAS. In particular, June mean temperature has the highest predictive power for species changes at the 5 m SAS. Recorded changes in species richness point more towards fluctuations within a plant community’s normal range, although there seem to be more significant diversity changes in higher summits related to aspects. Our work provides additional evidence to assess the effects of climate change on plant diversity in Mediterranean mountains and particularly those of islands which remain understudied.

scholarly journals Body size, reef area and temperature predict global reef-fish species richness across spatial scales

2018 ◽  
Vol 28 (3) ◽  
pp. 315-327 ◽  
Author(s):  
D. R. Barneche ◽  
E. L. Rezende ◽  
V. Parravicini ◽  
E. Maire ◽  
G. J. Edgar ◽  
...  
Keyword(s):  
Species Richness ◽  
Body Size ◽  
Reef Fish ◽  
Fish Species ◽  
Spatial Scales ◽  
Reef Area ◽  
Reef Fish Species

scholarly journals What Does Productivity Really Mean? Towards an Integrative Paradigm in the Search for Biodiversity-Productivity Relationships

2013 ◽  
Vol 41 (1) ◽  
pp. 36 ◽  
Author(s):  
Liangjun HU ◽  
Qinfeng GUO
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Biomass Production ◽  
Real Root ◽  
Spatial Scaling ◽  
Ecological Processes ◽  
The Real ◽  
Community Or ◽  
Per Se ◽  
Underlying Mechanisms

How species diversity relates to productivity remains a major debate. To date, however, the underlying mechanisms that regulate the ecological processes involved are still poorly understood. Three major issues persist in early efforts at resolution. First, in the context that productivity drives species diversity, how the pathways operate is poorly-explained. Second, productivity  per se varies with community or ecosystem maturity. If diversity indeed drives productivity, the criterion of choosing appropriate measures for productivity is not available. Third, spatial scaling suggests that sampling based on small-plots may not be suitable for formulating species richness-productivity relationships (SRPRs). Thus, the long-standing assumption simply linking diversity with productivity and pursuing a generalizing pattern may not be robust. We argue that productivity, though defined as ‘the rate of biomass production’, has been measured in two ways environmental surrogates and biomass production leading to misinterpretations and difficulty in the pursuit of generalizable SRPRs. To tackle these issues, we developed an integrative theoretical paradigm encompassing richer biological and physical contexts and clearly reconciling the major processes of the systems, using proper productivity measures and sampling units. We conclude that loose interpretation and confounding measures of productivity may be the real root of current SRPR inconsistencies and debate.

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