scholarly journals Amphibian breeding phenology and reproductive outcome: an examination using terrestrial and aquatic sampling

2017 ◽  
Vol 95 (9) ◽  
pp. 673-684 ◽  
Author(s):  
C.H. Greenberg ◽  
S.A. Johnson ◽  
R. Owen ◽  
A. Storfer
Keyword(s):  
Sampling Methods ◽  
Amphibian Declines ◽  
Life Stages ◽  
Reproductive Outcome ◽  
Breeding Phenology ◽  
Local Species Richness ◽  
Larval Amphibians ◽  
High Incidence ◽  
Local Species ◽  
Aquatic Sampling

Worldwide amphibian declines highlight the need for programs that monitor species presence and track population trends. We sampled larval amphibians with a box trap at 3-week intervals for 23 months in eight wetlands, and concurrently trapped adults and juveniles with drift fences, to examine spatiotemporal patterns of tadpole occurrence; explore relationships between breeding effort, tadpole abundance, and recruitment; and compare the efficacy of both methods in detecting species presence and reproductive outcome. Intermittent detection of species within and among wetlands suggested high mortality, followed by deposition of new eggs and tadpole cohorts. Breeding effort, tadpole abundance, and juvenile recruitment were generally not correlated. The reasons for this may include differential bias in detecting species or life stages between methods and high incidence of egg or tadpole mortality. Drift fences detected more species than box traps, but each provided insights regarding amphibian presence and recruitment. Our results illustrate shortfalls in the ability of infrequent aquatic sampling to detect local species richness of larval amphibians, as occurrence of many species is spatially and temporally variable. We also show the importance of using different sampling methods to detect species’ presence, as well as difficulties associated with both methods in tracking breeding effort, tadpole occurrence, or reproductive outcome.

Annual fires reduce local species richness but do not homogenize the composition of savanna woody species

Flora ◽  
2021 ◽  
pp. 151868
Author(s):  
Karlo G. Guidoni-Martins ◽  
Leandro Maracahipes ◽  
Adriano S. Melo ◽  
Marcus V. Cianciaruso
Keyword(s):  
Species Richness ◽  
Woody Species ◽  
Local Species Richness ◽  
Local Species

scholarly journals Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales

2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Local Scale ◽  
Local Species Richness ◽  
Β Diversity ◽  
Arthropod Species ◽  
Α Diversity ◽  
Local Species ◽  
Richness Patterns

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

Amphibians of the Kayan Mentarang National Park (East Kalimantan, Indonesia): estimating overall and local species richness

2004 ◽  
Vol 17 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M. Veith ◽  
S. Wulffraat ◽  
J. Kosuch ◽  
G. Hallmann ◽  
H.-W. Henkel ◽  
...  
Keyword(s):  
Species Richness ◽  
National Park ◽  
East Kalimantan ◽  
Local Species Richness ◽  
Local Species

scholarly journals Characterization and comparison of poorly known moth communities through DNA barcoding in two Afrotropical environments in Gabon

Genome ◽  
2019 ◽  
Vol 62 (3) ◽  
pp. 96-107 ◽  
Author(s):  
Sylvain Delabye ◽  
Rodolphe Rougerie ◽  
Sandrine Bayendi ◽  
Myrianne Andeime-Eyene ◽  
Evgeny V. Zakharov ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Insect Communities ◽  
Biodiversity Research ◽  
Local Species Richness ◽  
Biodiversity Knowledge ◽  
Formidable Challenge ◽  
Entire Country ◽  
The Status ◽  
Local Species ◽  
Taxonomic Approach

Biodiversity research in tropical ecosystems—popularized as the most biodiverse habitats on Earth—often neglects invertebrates, yet invertebrates represent the bulk of local species richness. Insect communities in particular remain strongly impeded by both Linnaean and Wallacean shortfalls, and identifying species often remains a formidable challenge inhibiting the use of these organisms as indicators for ecological and conservation studies. Here we use DNA barcoding as an alternative to the traditional taxonomic approach for characterizing and comparing the diversity of moth communities in two different ecosystems in Gabon. Though sampling remains very incomplete, as evidenced by the high proportion (59%) of species represented by singletons, our results reveal an outstanding diversity. With about 3500 specimens sequenced and representing 1385 BINs (Barcode Index Numbers, used as a proxy to species) in 23 families, the diversity of moths in the two sites sampled is higher than the current number of species listed for the entire country, highlighting the huge gap in biodiversity knowledge for this country. Both seasonal and spatial turnovers are strikingly high (18.3% of BINs shared between seasons, and 13.3% between sites) and draw attention to the need to account for these when running regional surveys. Our results also highlight the richness and singularity of savannah environments and emphasize the status of Central African ecosystems as hotspots of biodiversity.

scholarly journals Long-term species richness-abundance dynamics in relation to species departures and arrivals in wintering urban bird assemblages

2019 ◽  
Vol 5 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jukka Suhonen ◽  
Jukka Jokimäki
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Total Abundance ◽  
Bird Species Richness ◽  
Abundance Dynamics ◽  
Local Species Richness ◽  
Local Species ◽  
The Mean ◽  
Urban Bird ◽  
Number Of Individuals

Abstract Temporal dynamics of local assemblages depend on the species richness and the total abundance of individuals as well as local departure and arrival rates of species. We used urban bird survey data collected from the same 31 study plots and methods during three winters (1991–1992; 1999–2000 and 2009–2010) to analyze the temporal relationship between bird species richness and total number of individuals (abundance). We also evaluated local departures and arrivals of species in each assemblage. In total, 13,812 individuals of 35 species were detected. The temporal variation in bird species richness followed the variation in the total number of individuals. The numbers of local departure and arrival events were similar. Also, the mean number of individuals of the recently arrived species (8.6) was almost the same as the mean number of individuals of the departed species (8.2). Risk of species departure was inversely related to number of individuals. Local species richness increased by one species when the total abundance of individuals increased by around 125 individuals and vice versa. Our results highlight the important role of local population departures and arrivals in determining the local species richness-abundance dynamics in human-dominated landscapes. Local species richness patterns depend on the total number of individuals as well as both the departure-arrival dynamics of individual species as well as the dynamics of all the species together. Our results support the more individuals hypothesis, which suggests that individual-rich assemblages have more species.

scholarly journals Three points of consideration before testing the effect of patch connectivity on local species richness: patch delineation, scaling and variability of metrics

2019 ◽  
Author(s):  
Fabien Laroche ◽  
Manon Balbi ◽  
Théophile Grébert ◽  
Franck Jabot ◽  
Frédéric Archaux
Keyword(s):  
Species Richness ◽  
Empirical Studies ◽  
Structural Connectivity ◽  
Dispersal Limitation ◽  
Dispersal Distance ◽  
Habitat Amount ◽  
Local Species Richness ◽  
Theory Of Island Biogeography ◽  
Local Species ◽  
Patch Connectivity

AbstractThe Theory of Island Biogeography (TIB) promoted the idea that species richness within sites depends on site connectivity, i.e. its connection with surrounding potential sources of immigrants. TIB has been extended to a wide array of fragmented ecosystems, beyond archipelagoes, surfing on the analogy between habitat patches and islands and on the patch-matrix framework. However, patch connectivity often little contributes to explaining species richness in empirical studies. Before interpreting this trend as questioning the broad applicability of TIB principles, one first needs a clear identification of methods and contexts where strong effects of patch structural connectivity are likely to occur. Here, we use spatially explicit simulations of neutral metacommunities to show that patch connectivity effect on local species richness is maximized under a set of specific conditions: (i) patch delineation should be fine enough to ensure that no dispersal limitation occurs within patches, (ii) patch connectivity indices should be scaled according to target organisms’ dispersal distance and (iii) the habitat amount around sampled sites (within a distance adapted to organisms’ dispersal) should be highly variable. When those three criteria are met, the absence of an effect of connectivity on species richness should be interpreted as contradicting TIB hypotheses

scholarly journals Contrasting the Effect of Forest Landscape Condition to the Resilience of Species Diversity in a Human Modified Landscape: Implications for the Conservation of Tree Species

Land ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 4 ◽  
Author(s):  
Mulugheta Ghebreslassie Araia ◽  
Paxie Wanangwa Chirwa ◽  
Eméline Sêssi Pélagie Assédé
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Species Diversity ◽  
Conservation Strategy ◽  
Forest Landscape ◽  
Leading Change ◽  
Forest Reserve ◽  
Local Species Richness ◽  
Β Diversity ◽  
Local Species

Using landscape moderation insurance and Intermediate Disturbance Hypothesis (IDH) as frameworks, this study assessed the response of local assemblage among different land use regimes (mean β-diversity), using the Jaccard dissimilarity matrix in contrasting Human Modified Forest Landscapes (HMFLs). The study was conducted at the relatively simplified Mafhela Forest Reserve and the complex Thathe Vondo Forest Reserve in South Africa. The patterns of overall β-diversity between HMFL and State-protected Indigenous Forests (SIF) were compared and the leading change drivers were then untangled. This study found that human disturbance affects mean β-diversity of local assemblages among land use regimes between the two HMFLs in an ecologically contrasting manner. The HMFL in Mafhela Forest Reserve had distinct local assemblages among land use regimes and did not conform to the expectation of IDH. On average, HMFL had the same average local species richness as SIF, mainly due to change in species composition (species replacement) induced by land use disturbance. Land use intensity gradient was the leading change driver to explain the overall β-diversity of the Mafhela Forest Reserve. The findings in the Thathe Vondo Forest Reserve were in contrast with the Mafhela Forest Reserve. Although on average the HMFL had the same local species richness as SIFs, this was mainly due to a trade-off of species gain in trees along the rivers and streams and species loss in Culturally Protected Areas (sacred forests) (CPA) as expected by IDH. The contrasting findings imply that the effectiveness of any alternative conservation strategy is context-dependent. The resilience of local assemblages and conservation value of HMFL depends on the condition of the overall forest landscape complexity and cannnot be captured by one theory, nor by one species diversity matrix (e.g., β-diversity or Richness). It thus demands the application of complementary theoretical frameworks and multilevel modeling.

scholarly journals Mapping landscape connectivity as a driver of species richness under tectonic and climatic forcing

2019 ◽  
Vol 7 (4) ◽  
pp. 895-910 ◽  
Author(s):  
Tristan Salles ◽  
Patrice Rey ◽  
Enrico Bertuzzo
Keyword(s):  
Species Richness ◽  
Landscape Connectivity ◽  
Tectonic Activity ◽  
Climatic Forcing ◽  
Mountainous Regions ◽  
Local Species Richness ◽  
Complex Interactions ◽  
Local Species ◽  
Elevational Range ◽  
A Site

Abstract. Species distribution and richness ultimately result from complex interactions between biological, physical, and environmental factors. It has been recently shown for a static natural landscape that the elevational connectivity, which measures the proximity of a site to others with similar habitats, is a key physical driver of local species richness. Here we examine changes in elevational connectivity during mountain building using a landscape evolution model. We find that under uniform tectonic and variable climatic forcing, connectivity peaks at mid-elevations when the landscape reaches its geomorphic steady state and that the orographic effect on geomorphic evolution tends to favour lower connectivity on leeward-facing catchments. Statistical comparisons between connectivity distribution and results from a metacommunity model confirm that to the 1st order, landscape elevation connectivity explains species richness in simulated mountainous regions. Our results also predict that low-connectivity areas which favour isolation, a driver for in situ speciation, are distributed across the entire elevational range for simulated orogenic cycles. Adjustments of catchment morphology after the cessation of tectonic activity should reduce speciation by decreasing the number of isolated regions.

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