scholarly journals Seasonal regulation of herbivory and nutrient effects on macroalgal recruitment and succession in a Florida coral reef

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2643 ◽  
Author(s):  
Alain Duran ◽  
Ligia Collado-Vides ◽  
Deron E. Burkepile
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Nutrient Availability ◽  
Nutrient Enrichment ◽  
Community Dynamics ◽  
Species Abundance ◽  
Warm Season ◽  
Winter Mortality ◽  
Exclusion Experiment ◽  
Herbivore Exclusion

Herbivory and nutrient enrichment are drivers of benthic dynamics of coral reef macroalgae; however, their impact may vary seasonally. In this study we evaluated the effects of herbivore pressure, nutrient availability and potential propagule supply on seasonal recruitment and succession of macroalgal communities on a Florida coral reef. Recruitment tiles, replaced every three months, and succession tiles, kept in the field for nine months, were established in an ongoing factorial nutrient enrichment-herbivore exclusion experiment. The ongoing experiment had already created very different algal communities across the different herbivory and nutrient treatments. We tracked algal recruitment, species richness, and species abundance through time. Our results show seasonal variation in the effect of herbivory and nutrient availability on recruitment of coral reef macroalgae. In the spring, when there was higher macroalgal species richness and abundance of recruits, herbivory appeared to have more control on macroalgal community structure than did nutrients. In contrast, there was no effect of either herbivory or nutrient enrichment on macroalgal communities on recruitment tiles in cooler seasons. The abundance of recruits on tiles was positively correlated with the abundance of algal in the ongoing, established experiment, suggesting that propagule abundance is likely a strong influence on algal recruitment and early succession. Results of the present study suggest that abundant herbivorous fishes control recruitment and succession of macroalgae, particularly in the warm season when macroalgal growth is higher. However, herbivory appears less impactful on algal recruitment and community dynamics in cooler seasons. Ultimately, our data suggest that the timing of coral mortality (e.g., summer vs. winter mortality) and freeing of benthic space may strongly influence the dynamics of algae that colonize open space.

Effects of herbivore exclusion and nutrient enrichment on coral reef macroalgae and cyanobacteria

Coral Reefs ◽  
2001 ◽  
Vol 19 (4) ◽  
pp. 318-329 ◽  
Author(s):  
R. Thacker ◽  
D. Ginsburg ◽  
V. Paul
Keyword(s):  
Coral Reef ◽  
Nutrient Enrichment ◽  
Herbivore Exclusion

scholarly journals STRUKTUR KOMUNITAS IKAN TARGET DI TERUMBU KARANG PULAU HOGOW DAN PUTUS-PUTUS SULAWESI UTARA

2011 ◽  
Vol 7 (2) ◽  
pp. 60 ◽  
Author(s):  
Unstain NWJ Rembet ◽  
Mennofatria Boer ◽  
Dietriech G Bengen ◽  
Achmad Fahrudin
Keyword(s):  
Multivariate Analysis ◽  
Species Richness ◽  
Coral Reef ◽  
Species Diversity ◽  
Species Abundance ◽  
Controlling Factors ◽  
Ecological Groups ◽  
Species Evenness ◽  
Target Fish ◽  
Abundance And Diversity

ABSTRACTCommunity structure of target fishes was analyzed to understand their response to different conditions of coral reefs in several places of Hugow and Putus-Putus islands. This study focused on species abundance and diversity including Shannon-Wiener’s species diversity (H’), species richness (SR), species evenness (J’) and dominance (d) indices, respectively. A multivariate analysis was used for the classification or correspondence factorial analyses. The result recorded 4,501 individuals belonging to 52 species of target fishes. Both cluster and correspondence analyses clearly recognized 3 groups of target fish with 2 major controlling factors for the development of these 3 ecological groups, i.e. coral reef conditions and geographic position to the hydrodynamic condition.ABSTRAKStruktur komunitas ikan target dianalisis untuk melihat respon ikan target terhadap perbedaan kondisi terumbu karang di beberapa lokasi Pulau Hogow dan Putus-Putus. Penelitian ini dilakukan pada bulan Oktober 2010 dengan pengambilan data di 6 stasiun. Dalam penelitian ini telah dikaji variabel komunitas seperti kelimpahan dan keanekaragaman spesies termasuk indeks keanekaragaman spesies Shannon-Wiener (H’), indeks kekayaan spesies (SR), indeks kemerataan spesies (J’) dan indeks dominasi (d). Untuk melihat assemblage ikan target dilakukan analisis multivariat baik analisis klasifikasi maupun analisis faktorial koresponden. Dalam penelitian ini diperoleh 4501 indidu yang termasuk dalam 52 spesies ikan target. Analisis multivariat baik analisis cluster maupun analisis koresponden telah memisahkan dengan jelas 3 grup ikan target, dimana terdapat dua faktor utama pengendali pembentukan 3 grup ekologis ini yakni faktor kondisi terumbu karang dan faktor posisi lokasi terhadap kondisi hidrodinamika perairan.

scholarly journals Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1459 ◽  
Author(s):  
Elena L.E.S. Wagner ◽  
Dominique G. Roche ◽  
Sandra A. Binning ◽  
Sharon Wismer ◽  
Redouan Bshary
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Reef Fish ◽  
Fish Species ◽  
Patch Size ◽  
Coral Cover ◽  
Species Abundance ◽  
Fish Abundance ◽  
Live Coral ◽  
Live Coral Cover

Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the absence of large disturbances, we found that live coral cover, reef fish abundance and fish species richness did not differ in 1997 compared to 2007. Fish abundance and species richness on patches was largely related to the presence of shelters (caves and/or holes), live coral cover and patch size (volume). The presence of the ectoparasite-eating cleaner wrasse,Labroides dimidiatus, was also positively related to fish species richness. Our results underscore the importance of physical reef characteristics, such as patch size and shelter availability, in addition to biotic characteristics, such as live coral cover and cleaner wrasse abundance, in supporting reef fish species richness and abundance through time in a relatively undisturbed and understudied region.

scholarly journals Effects of Grazer Exclusion on Carbon Cycling in Created Freshwater Wetlands

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 805
Author(s):  
Delanie M. Spangler ◽  
Anna Christina Tyler ◽  
Carmody K. McCalley
Keyword(s):  
Soil Carbon ◽  
Carbon Cycling ◽  
Belowground Biomass ◽  
Freshwater Wetlands ◽  
Wetland Creation ◽  
Free Access ◽  
Exclusion Experiment ◽  
Herbivore Exclusion ◽  
Sequestration Potential ◽  
Natural Wetlands

Wetland ecosystems play a significant role in the global carbon cycle, and yet are increasingly threatened by human development and climate change. The continued loss of intact freshwater wetlands heightens the need for effective wetland creation and restoration. However, wetland structure and function are controlled by interacting abiotic and biotic factors, complicating efforts to replace ecosystem services associated with natural wetlands and making ecologically-driven management imperative. Increasing waterfowl populations pose a threat to the development and persistence of created wetlands, largely through intensive grazing that can shift vegetation community structure or limit desired plant establishment. This study capitalized on a long-term herbivore exclusion experiment to evaluate how herbivore management impacts carbon cycling and storage in a created wetland in Western New York, USA. Vegetation, above- and belowground biomass, soil carbon, carbon gas fluxes and decomposition rates were evaluated in control plots with free access by large grazers and in plots where grazers had been excluded for four years. Waterfowl were the dominant herbivore at the site. Grazing reduced peak growing season aboveground biomass by over 55%, and during the summer, gross primary productivity doubled in grazer exclusion plots. The shift in plant productivity led to a 34% increase in soil carbon after exclusion of grazers for five growing seasons, but no change in belowground biomass. Our results suggest that grazers may inhibit the development of soil carbon pools during the first decade following wetland creation, reducing the carbon sequestration potential and precluding functional equivalence with natural wetlands.

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.

Do predaceous stoneflies and siltation affect the structure of stream insect communities colonizing enclosures?

1985 ◽  
Vol 63 (7) ◽  
pp. 1519-1530 ◽  
Author(s):  
Barbara L. Peckarsky
Keyword(s):  
New York ◽  
Species Richness ◽  
Prey Species ◽  
Species Abundance ◽  
Benthic Invertebrate ◽  
Taxonomic Composition ◽  
Community Response ◽  
Insect Communities ◽  
Composite Effect ◽  
Benthic Invertebrate Community

Experiments in Colorado and New York streams assessed the effects of predaceous stoneflies on benthic invertebrate community establishment in enclosures providing uncolonized habitat. Aspects of prey community structure measured were density, species richness, relative species abundance, and body size. Unexpected inorganic sediment deposition allowed evaluation of direct effects on Colorado stream benthos and indirect effects on predation. Predaceous perlids and perlodids consistently reduced the density and, therefore, rate of prey community establishment in enclosures. Although New York perlids disproportionately reduced densities of some prey species, Colorado stoneflies caused nonsignificant declines in individual prey species densities, the composite effect of which was a significant whole-community response. Predators did not affect prey species richness nor change the taxonomic composition (species additions or deletions) of communities colonizing enclosures. However, the relative abundance of prey taxa differed significantly between cages with and without predators. Most species showed no size differences between individuals colonizing enclosures with predators and those colonizing control enclosures, with a few interesting exceptions. The deposition of silt eliminated the predator effects on prey density, as well as directly causing significant reductions in many Colorado benthic populations. This result demonstrates that abiotic disturbances can periodically override the effects of predation on stream insect communities colonizing enclosures.

scholarly journals Complementarity of Rotating Video and Underwater Visual Census for Assessing Species Richness, Frequency and Density of Reef Fish on Coral Reef Slopes

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e84344 ◽  
Author(s):  
Delphine Mallet ◽  
Laurent Wantiez ◽  
Soazig Lemouellic ◽  
Laurent Vigliola ◽  
Dominique Pelletier
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Reef Fish ◽  
Visual Census ◽  
Underwater Visual Census

scholarly journals The use of Shanon Weiners diversity index in the assessment of floral diversity and equitability of Neni–Nimo Watershed in Anaocha L.G.A. of Anambra State, Nigeria

2021 ◽  
Vol 16 (2) ◽  
pp. 155-158
Author(s):  
Ezenwatah Ifeoma Susan ◽  
Ukpaka Chukwujekwu Gratius ◽  
Onyemeka Regland Michael ◽  
Afulukwe Stella Chinyere ◽  
Okoye Elochukwu Chidubem Sunday
Keyword(s):  
Species Richness ◽  
Plant Growth ◽  
Diversity Index ◽  
Block Design ◽  
Species Abundance ◽  
P Value ◽  
Growth Forms ◽  
Anambra State ◽  
Floral Diversity ◽  
Current Usage

The study on the floral diversity of Neni-Nimo watershed in Anaocha L.G.A. of Anambra State was conducted between November 2009 and July 2020. The aim of the study was to find out the species richness and the floral biodiversity of the watershed. In this study, the watershed was divided into three sites, the forested site, the fallow site and the current usage site. The experiment was laid out in a Randomized Complete Block Design. The ecological methods used in this study are the Point Centred Plotless Count sampling technique for areas dominated by trees while the Plot Count technique using quadrats were used for sampling the areas dominated by forbs, shrubs, climbers and grasses. The vegetation data collected was used to estimate the species richness of the different plant growth forms, the diversity and equitability of the various growth forms encountered were calculated using Shanon Weiners diversity index. The Shanno Weiners diversity index shows that the forested areas had the highest floral biodiversity than the fallow and current usage area. Regression analysis shows that a significant relationship exists between species abundance and floral biodiversity at a p-value of <0.05 for all plant growth forms in the watershed except for grasses and as abundance increases, diversity also increases.

scholarly journals Experimental reef communities persist under future ocean acidification and warming

2021 ◽  
Author(s):  
Christopher Jury ◽  
Keisha Bahr ◽  
Evan Barba ◽  
Russell Brainard ◽  
Annick Cros ◽  
...  
Keyword(s):  
Experimental Study ◽  
Species Richness ◽  
Coral Reef ◽  
Coral Reefs ◽  
Ocean Acidification ◽  
Community Composition ◽  
Functional State ◽  
Reef Communities ◽  
Paris Climate Agreement

Abstract Coral reefs are among the most sensitive ecosystems affected by ocean acidification and warming, and are predicted to shift from net accreting calcifier-dominated systems to net eroding algal-dominated systems over the coming decades. Here we present a long-term experimental study examining the responses of entire mesocosm coral reef communities to acidification (-0.2 pH units), warming (+ 2°C), and combined future ocean (-0.2 pH, + 2°C) treatments. We show that under future ocean conditions, net calcification rates declined yet remained positive, corals showed reduced abundance yet were not extirpated, and community composition shifted while species richness was maintained. Our results suggest that under Paris Climate Agreement targets, coral reefs could persist in an altered functional state rather than collapse.

Sign in / Sign up

Export Citation Format

Share Document