Vegetation pattern divergence between dry and wet season in a semiarid savanna – Spatio-temporal dynamics of plant diversity in northwest Namibia

Wet-season flooding causes dietary shifts in tropical freshwater fish by regulating instream productivity, habitat structure and food availability. These dynamics have been comprehensively documented worldwide, but data are limited for Australia’s Wet Tropics rivers. The aim of the present study was to extend our earlier fish–habitat model for these systems by examining the role of trophic dynamics in determining fish assemblage composition. Chlorophyll a and phaeophytin concentrations, benthic and littoral invertebrates and fish were collected at four sites in the lower Mulgrave River under a range of flow conditions. Wet-season flooding caused significant reductions in instream productivity, whereas habitat disturbance reduced densities and abundances of littoral and benthic invertebrates. However, volumetric gut contents of 1360 fish, from 36 species, revealed seasonal shifts in guild membership by only two species, with fish moving between sites to target their preferred prey items – largely irrespective of differences in habitat structure. As a result, the food consumed by the fish community present at each site closely reflected the seasonal availability of food resources. The present paper questions whether fish community composition in small tropical rivers can be accurately predicted from habitat surrogates alone and encourages consideration of constraints imposed by the trophic dynamics and reproductive ecology of fish.

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Spatial-temporal dynamics of biome Cerrado using different vegetation indexes

Australian Journal of Crop Science ◽

10.21475/ajcs.19.13.09.p1531 ◽

2019 ◽

pp. 1438-1446

Author(s):

Jefferson Vieira José ◽

Niclene Ponce Rodrigues de Oliveira ◽

Tonny Jose de Araújo da Silva ◽

Edna Maria Bonfim Silva ◽

Jéfferson de Oliveira Costa ◽

...

Keyword(s):

Temporal Dynamics ◽

Vegetation Indices ◽

Brazilian Cerrado ◽

Wet Season ◽

Mato Grosso ◽

Cerrado Biome ◽

Vegetation Indexes ◽

Different Seasons ◽

Spatio Temporal ◽

Landsat Satellite

The Cerrado ranks among the major biomes in Brazil and its vegetation can now be monitored through remote sensing, although environmental factors can affect the use of this technique. Thus, the possibility of conducting a study in a region with negligible anthropogenic intrusion may become a potential reference work in controlling the spatio-temporal alterations occurring in the Cerrado biome. This study aimed at assessing the spatio-temporal dynamics of the Brazilian Cerrado biome at different seasons of the year (wet and dry), employing various vegetation indices (NDVI, SAVI, EVI and LAI) drawn from the LANDSAT satellite images 8. The study itself was conducted in the Tadarimana Indigenous reserve situated in the State of Mato Grosso, Brazil. Extending across an area of 9952 hectares, the predominant vegetation cover in this reserve include the Savanna-Seasonal Contact (84.78%) and Savanna (15.22%). The data was analyzed using descriptive statistics and the best characterization of the vegetation was identified in the regions where higher variability was observed in the responses of the vegetation indices. The LAI revealed the best performance when the spatio-temporal dynamics of the Brazilian Cerrado biome was assessed. The wet season displayed the highest values among the different vegetation indices, despite the variances.

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Population dynamics of the coconut crab Birgus latro on Aldabra Atoll, Seychelles

Marine Ecology Progress Series ◽

10.3354/meps13672 ◽

2021 ◽

Vol 665 ◽

pp. 103-113

Author(s):

JC Appoo ◽

EF Cagua ◽

J van de Crommenacker ◽

AJ Burt ◽

P Pistorius ◽

...

Keyword(s):

Temporal Dynamics ◽

Lunar Cycle ◽

Average Density ◽

Spatial And Temporal Variability ◽

Source Population ◽

Lunar Phase ◽

Wet Season ◽

Conservation Actions ◽

Spatio Temporal ◽

Substantial Decline

Birgus latro, the largest terrestrial arthropod in the world, has undergone a substantial decline globally over the last decades, with only a few healthy populations remaining where they are actively protected. We aimed to quantify demographic and spatio-temporal dynamics of a protected population of B. latro on Aldabra Atoll (Seychelles). Based on results along 2 transects on the atoll from 2007 to 2016, we calculated an average (±SE) density of 23.7 ± 1.1 ind. ha-1. This suggests a population of around 5000 B. latro in the coastal area of Picard Island, which is likely to be an underestimate due to the cryptic nature of the species. The average density within the study area was stable over the study period, and over the yearly cycle, the population exhibited high spatial and temporal variability in count, size and sex ratio and in association with the lunar cycle. Aldabra’s B. latro population is male-biased (3:1 male:female) and sexually dimorphic, with males being larger than females. Males and females moult at different times of the year, and the breeding season overlaps with the region’s wet season (December-March) and was in synchrony with the lunar phase. B. latro on Aldabra present colour polymorphism in a 4:1:1 ratio of orange:blue:intermediate (mixture of orange and blue). Results confirm that Aldabra is an important refuge for B. latro and potentially a natural source population for other areas in the region. Similar long-term studies on B. latro are encouraged to improve knowledge on the species and to support conservation actions to halt the species’ decline.

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Spatio-temporal variations in abundance and assemblage patterns of fish larvae and their relationships to environmental variables in Sirindhron Reservoir of the Lower Mekong Basin, Thailand

Indian Journal of Fisheries ◽

10.21077/ijf.2016.63.3.54491-02 ◽

2016 ◽

Vol 63 (3) ◽

Author(s):

Tuantong Jutagate ◽

Achara Rattanachai ◽

Suriya Udduang ◽

Sithan Lek-Ang ◽

Sovan Lek

Keyword(s):

Species Richness ◽

Temporal Dynamics ◽

Larval Fish ◽

Fish Larvae ◽

Abundant Species ◽

Temporal Variations ◽

Larval Abundance ◽

Wet Season ◽

North East ◽

Spatio Temporal

The spatio-temporal dynamics of fish larvae in Sirindhron Reservoir, north-east Thailand, were investigated from February 2008 to January 2009. The five most abundant species accounted for 53.6% of the total catch and comprised Clupeicthys aesarnensis, Rasbora borapetensis, Barbonymus gonionotus, Esomus metallicus and Oreochromis niloticus. Total larval abundance and species richness varied among sampling months but did not vary with zones in the reservoir. The abundance and species richness of fish larvae showed correlation with flooding, vegetation cover, water level, water temperature and turbidity. A self-organising map (SOM) was used to represent the larval fish assemblage patterns and three assemblage patterns were clearly distinguished primarily according to seasons. In conclusion, the fish larval abundance was greatest during the wet season and the most diverse assemblages were found in the zones adjacent to the connected river upstream during the wet season.

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Nonlinear Spatio-Temporal Dynamics and Chaos in Semiconductors

10.1017/cbo9780511524615 ◽

2001 ◽

Cited By ~ 136

Author(s):

Eckehard Schöll

Keyword(s):

Temporal Dynamics ◽

Spatio Temporal

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Spatio-temporal dynamics of ascidian larval recruitment and colony abundance in a non-indigenous Newfoundland population

Marine Ecology Progress Series ◽

10.3354/meps12437 ◽

2017 ◽

Vol 585 ◽

pp. 99-112 ◽

Cited By ~ 2

Author(s):

KCK Ma ◽

D Deibel ◽

JB Lowen ◽

CH McKenzie

Keyword(s):

Temporal Dynamics ◽

Larval Recruitment ◽

Spatio Temporal

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Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

Marine Ecology Progress Series ◽

10.3354/meps13211 ◽

2020 ◽

Vol 637 ◽

pp. 117-140 ◽

Cited By ~ 1

Author(s):

DW McGowan ◽

ED Goldstein ◽

ML Arimitsu ◽

AL Deary ◽

O Ormseth ◽

...

Keyword(s):

Temporal Dynamics ◽

Marine Ecosystem ◽

Gulf Of Alaska ◽

Data Series ◽

Limited Information ◽

Important Species ◽

Multiple Data ◽

Spatial And Temporal Dynamics ◽

Spawning Areas ◽

Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

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