Zoochory of zooplankton: seasonality and bird morphological diversity can influence metacommunity dynamics of temporary ponds

2019 ◽  
Vol 41 (4) ◽  
pp. 465-477 ◽  
Author(s):  
Cláudio Simões de Morais-Junior ◽  
Mauro de Melo-Júnior ◽  
Thiago Gonçalves-Souza ◽  
Rachel Maria de Lyra-Neves
Keyword(s):  
Water Availability ◽  
Morphological Diversity ◽  
Temporary Ponds ◽  
Life History Strategies ◽  
Bird Diversity ◽  
Wet Season ◽  
Dispersal Capacity ◽  
Selective Forces ◽  
Metacommunity Dynamics ◽  
Zooplankton Communities

Abstract Harsh and unstable aquatic environments present selective forces that influence environmental heterogeneity, dispersal capacity and specific life history strategies that, in turn, affect species distribution and metacommunity dynamics. To date, relatively few studies have examined the potential of bird-mediated dispersal to connect isolated ephemeral habitats. We used zooplankton from temporary ponds to examine the effects of bird morphological diversity and water availability on microcrustacean diversity in temporary ponds. Three bird feet models were constructed based on small, large and webbed anisodactylous forms in order to simulate bird walking on the pond shore. Bird and zooplankton communities were sampled in two temporary ponds and experimentally simulated zooplankton dispersal by bird on dry sediments. We surveyed in two contrasting seasonal periods. Overall, water availability does affect zooplankton composition, and birds with large feet have higher dispersal capacity. In addition, birds with different feet size and shape carry distinct zooplankton species. During the dry season, sediments hold 100% more species than in the wet season, which indicates that birds have higher potential for dispersing zooplankton in drought conditions. Our findings suggest that bird diversity can maintain zooplankton metacommunities by rescuing dormant organisms from dry ponds and connecting to any available aquatic habitats.

Distribution of aquatic pulmonate snail species in contrasting habitats within the Ross River Reservoir (stage 2a), tropical Northern Australia

1995 ◽  
Vol 46 (7) ◽  
pp. 1033 ◽  
Author(s):  
M Hurley ◽  
MN Hearnden ◽  
BH Kay
Keyword(s):  
Temporary Ponds ◽  
Chemical Characteristics ◽  
Snail Species ◽  
Northern Australia ◽  
Wet Season ◽  
Habitat Types ◽  
Physico Chemical ◽  
River Reservoir ◽  
Macrophyte Species ◽  
Contrasting Habitats

Monthly distributions of three snail species in three distinct habitat types from February 1992 to May 1993 were found to be variable, with peak abundances occurring predominantly in the late wet season (March to May) for Amerianna carinata and Gyraulus gilberti and in the late dry season (September to November) for Austropeplea lessoni. No consistently positive or negative patterns of correlation were recorded between numbers of snails and physico-chemical characteristics or the amount or composition of emergent and submerged macrophyte species. However, highest densities of A. lessoni and A. carinata were recorded in temporary ponds, where the biomass of periphyton was greatest. Significantly lower amounts of periphyton were recorded from open bays and permanent creeks. Highest densities of G. gilberti occurred in permanent creeks. Physico-chemical variables, rainfall patterns and macrophyte species were not good indicators of snail abundance in the Ross River reservoir. The best indicator of snail density appeared to be whether vegetated habitat is located within open bays, permanent creeks or isolated peripheral ponds.

scholarly journals Environmental Determinants Influencing Seasonal Variations of Bird Diversity and Abundance in Wetlands, Northern Region (Ghana)

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Collins Ayine Nsor ◽  
Edward Adzesiwor Obodai
Keyword(s):  
Seasonal Variations ◽  
Bird Community ◽  
Iucn Red List ◽  
Northern Region ◽  
Dry Season ◽  
Bird Diversity ◽  
Environmental Determinants ◽  
Wet Season ◽  
Bird Abundance ◽  
Bubulcus Ibis

The study assessed major environmental determinants influencing bird community in six wetlands over a 2-year period. A combination of visual and bird sounding techniques was used to determine the seasonal variations in bird abundance, while ordination techniques were performed to determine the influence of environmental factors on bird assemblage. A total of 1,169 birds from 25 species and 885 individuals from 23 species were identified in the wet and dry season, respectively. The shallow close marshes supported the greatest number of birds (P<0.05) compared to the riparian wetlands. Bird diversity was significantly higher in the wet season than in the dry season (F=4.101,P<0.05). Cattle egret (Bubulcus ibis) and marsh warbler (Acrocephalus palustris) were the most abundant. Using the IUCN “Red List” database guide, we noted that 96.2% of birds identified were least concern (LC). The yellow weaver bird (Ploceous megarhrynchus) was the only vulnerable species (VU) and represented 3.8%. From the three variables tested, bushfire and farming practices were the major threats and cumulatively explained 15.93% (wet season) and 14.06% (dry season) variations in bird diversity and abundance. These findings will help wetland managers design conservation measures to check current threats on birds from becoming vulnerable in the future.

Impact of eastern mosquitofish, Gambusia holbrooki, on temporary ponds: insights on how predation may structure zooplankton communities

2017 ◽  
Vol 27 (2) ◽  
pp. 124-132 ◽  
Author(s):  
Dalal Haiahem ◽  
Laïd Touati ◽  
Nasser Baaziz ◽  
Farrah Samraoui ◽  
Ahmed H. Alfarhan ◽  
...  
Keyword(s):  
Temporary Ponds ◽  
Gambusia Holbrooki ◽  
Eastern Mosquitofish ◽  
Zooplankton Communities

A field experiment to determine the effect of dry-season irrigation on vegetative and reproductive traits in the wet-deciduous tree Bonellia nervosa

2019 ◽  
Vol 36 (1) ◽  
pp. 29-35
Author(s):  
Octavio Sánchez ◽  
Mauricio Quesada ◽  
Rodolfo Dirzo ◽  
Carl D. Schlichting
Keyword(s):  
Field Experiment ◽  
Water Availability ◽  
Irrigation Treatment ◽  
Reproductive Traits ◽  
Dry Season ◽  
Leaf Phenology ◽  
Deciduous Tree ◽  
Wet Season ◽  
Seasonally Dry ◽  
Carbohydrate Concentration

AbstractSeasonally dry tropical forests (SDTFs) stand out by the diversity of phenological patterns used by plants to deal with dry periods. Although the predominant phenological pattern is dry deciduousness, in Mesoamerican SDTFs the heliophilous tree species Bonellia (formerly Jacquinia) nervosa displays an unusual inverted leaf phenology, producing and holding leaves through the dry season while becoming deciduous in the rainy season. Applying a dry season irrigation field experiment (no water, low watering, high watering), we studied the consequences of contrasting water availability from a phenological plasticity response perspective. Contrary to our expectations, our results show no effect of irrigation treatment on leaf phenology. In addition, mid-day twig water potential showed no significant differences across treatments, but reproductive phenological responses varied among treatments: canopy flowering per cent decreased gradually until the beginning of the wet season in all treatments; meanwhile canopy fruit per cent showed a significant decline under low irrigation. Finally, non-structural carbohydrate concentration (starch) was significantly higher in the high irrigation treatment. Our results showed that inverted leaf phenology remains unaffected regardless of supplemental water availability, and suggest a reallocation of non-structural carbohydrates to fruits and seeds in high-irrigation treatments. Given the current and expected increase in extreme drought events, investigations on the responses of trees of different phenologies, including those of inverted leafing such as Bonellia nervosa, are warranted.

scholarly journals Trade-offs direct the evolution of coloration in Galápagos land snails

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182278 ◽  
Author(s):  
A. C. Kraemer ◽  
C. W. Philip ◽  
A. M. Rankin ◽  
C. E. Parent
Keyword(s):  
Related Species ◽  
Morphological Diversity ◽  
Land Snails ◽  
Morphological Diversification ◽  
Avian Predation ◽  
Trade Offs ◽  
Signature Of Selection ◽  
Selective Forces

Increasingly, multiple selective factors are recognized as jointly contributing to the evolution of morphology. What is not clear is how these forces vary across communities to promote morphological diversification among related species. In this study of Galápagos endemic snails (genus Naesiotus ), we test several hypotheses of colour evolution. We observe mockingbirds (genus Mimus ) predating live snails and find that avian predation selects against conspicuous shells. The evolutionary outcome of this selection is a diversity of shell colours across snails of the archipelago, each closely matching local backgrounds. We also find that snails more regularly exposed to the hot, equatorial sun reflect more light than shells of species from shadier habitats, suggesting a role for thermoregulatory constraints directing colour evolution. The signature of thermoregulatory selection is most clear in comparatively young communities (on the youngest islands), while the signature of selection from predators is most evident in older communities (on the older islands). Together, our findings point to a scenario of shifting selective forces along island ontogeny and community maturity that lead to the distribution of snail coloration we observe in Galápagos. Complex selective regimes such as these may have more responsibility for morphological diversity than is currently recognized.

scholarly journals Projection of Water Availability and Sustainability in Nigeria Due to Climate Change

2021 ◽  
Vol 13 (11) ◽  
pp. 6284
Author(s):  
Mohammed Sanusi Shiru ◽  
Shamsuddin Shahid ◽  
Inhwan Park
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
General Circulation ◽  
Water Storage ◽  
Coupled Model ◽  
General Circulation Models ◽  
Research Unit ◽  
Wet Season ◽  
Spatiotemporal Changes ◽  
Terrestrial Water

This study projects water availability and sustainability in Nigeria due to climate change. This study used Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage data (TWS), Global Precipitation Climatology Center (GPCC) precipitation data and Climate Research Unit (CRU) temperature data. Four general circulation models (GCMs) of the Coupled Model Intercomparison Project 5 were downscaled using the best of four downscaling methods. Two machine learning (ML) models, RF and SVM, were developed to simulate GRACE TWS data for the period 2002–2016 and were then used for the projection of spatiotemporal changes in TWS. The projected TWS data were used to assess the spatiotemporal changes in water availability and sustainability based on the reliability–resiliency–vulnerability (RRV) concept. This study revealed that linear scaling was the best for downscaling over Nigeria. RF had better performance than SVM in modeling TWS for the study area. This study also revealed there would be decreases in water storage during the wet season (June–September) and increases in the dry season (January–May). Decreases in projected water availability were in the range of 0–12 mm for the periods 2010–2039, 2040–2069, and 2070–2099 under RCP2.6 and in the range of 0–17 mm under RCP8.5 during the wet season. Spatially, annual changes in water storage are expected to increase in the northern part and decrease in the south, particularly in the country’s southeast. Groundwater sustainability was higher during the period 2070–2099 under all RCPs compared to the other periods and this can be attributed to the expected increases in rainfall during this period.

scholarly journals Water Use Characteristics of the Common Tree Species in Rock-dominated and Thin-soil Environments in Subtropical Monsoon Climate Region

2021 ◽  
Author(s):  
Jianbo Jia ◽  
Wende Yan ◽  
Jia Lu ◽  
Wenping Deng
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Use ◽  
Water Availability ◽  
Precipitation Amount ◽  
Monsoon Climate ◽  
Wet Season ◽  
Antecedent Precipitation ◽  
Subtropical Monsoon Climate ◽  
Rocky Habitats

Abstract Variations in precipitation pattern under climate changes influence water availability that have important implications for plants water use and vegetation sustainability. However, the water use characteristic of the main tree species under different temporal-spatial of water availability remain poorly understood, especially in high temporal-spatial heterogeneity area, such as subtropical monsoon climate region of China. We investigated water use characteristics of the most widely and common natural trees, Mallotus philippensis and Celtis biondii , in edaphic and rocky habitats. We measured the δD and δ 18 O values of xylem and soil water and water potential of plant leaves during the wet season in 2020. The results showed that the two species mainly absorbed soil water from shallow layers and switched for deeper layers during the late of the wet season in both habitats. But the plant water sources were different in edaphic and rocky habitats when the antecedent precipitation was much high, deep layers soil water in the former and still shallow layers in the latter. The two species had no significant differences in water uptake depth, but notably distinction in the diurnal water potential ranges. M. philippensis maintained less negative predawn and midday water potential, whereas C. biondii showed higher diurnal water potential ranges. Besides, the water potential of C. biondii were negatively associated with antecedent precipitation amount. These results indicate that there is significant eco-physiological niche segregation but no ecohydrological segregation co-existing species in communities. Besides, antecedent precipitation amount and habitat differences were the main factors influencing the plant water uptake depth. While the relationship between leaf physiological traits and water availability was affected by the species types, rather than the habitats. Furthermore, during the long drought in growing season, there are probable divergent responses of M. philippensis and C. biondii , such as growth restriction and hydraulic failure. But when the precipitation is heavy and long, these natural species could increase the ecohydrological linkages between ecosystem and the deep-layer system in edaphic habitat.

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