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1.
Syst Biol ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38934241

RESUMO

Cyanobacteria are the only prokaryotes to have evolved oxygenic photosynthesis paving the way for complex life. Studying the evolution and ecological niche of cyanobacteria and their ancestors is crucial for understanding the intricate dynamics of biosphere evolution. These organisms frequently deal with environmental stressors such as salinity and drought, and they employ compatible solutes as a mechanism to cope with these challenges. Compatible solutes are small molecules that help maintain cellular osmotic balance in high salinity environments, such as marine waters. Their production plays a crucial role in salt tolerance, which, in turn, influences habitat preference. Among the five known compatible solutes produced by cyanobacteria (sucrose, trehalose, glucosylglycerol, glucosylglycerate, and glycine betaine), their synthesis varies between individual strains. In this study, we work in a Bayesian stochastic mapping framework, integrating multiple sources of information about compatible solute biosynthesis in order to predict the ancestral habitat preference of Cyanobacteria. Through extensive model selection analyses and statistical tests for correlation, we identify glucosylglycerol and glucosylglycerate as the most significantly correlated with habitat preference, while trehalose exhibits the weakest correlation. Additionally, glucosylglycerol, glucosylglycerate, and glycine betaine show high loss/gain rate ratios, indicating their potential role in adaptability, while sucrose and trehalose are less likely to be lost due to their additional cellular functions. Contrary to previous findings, our analyses predict that the last common ancestor of Cyanobacteria (living at around 3180 Ma) had a 97% probability of a high salinity habitat preference and was likely able to synthesise glucosylglycerol and glucosylglycerate. Nevertheless, cyanobacteria likely colonized low-salinity environments shortly after their origin, with an 89% probability of the first cyanobacterium with low-salinity habitat preference arising prior to the Great Oxygenation Event (2460 Ma). Stochastic mapping analyses provide evidence of cyanobacteria inhabiting early marine habitats, aiding in the interpretation of the geological record. Our age estimate of ~2590 Ma for the divergence of two major cyanobacterial clades (Macro- and Microcyanobacteria) suggests that these were likely significant contributors to primary productivity in marine habitats in the lead-up to the Great Oxygenation Event, and thus played a pivotal role in triggering the sudden increase in atmospheric oxygen.

2.
J Anat ; 245(3): 451-466, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38733157

RESUMO

The family Bovidae [Mammalia: Artiodactyla] is speciose and has extant representatives on every continent, forming key components of mammal communities. For these reasons, bovids are ideal candidates for studies of ecomorphology. In particular, the morphology of the bovid humerus has been identified as highly related to functional variables such as body mass and habitat. This study investigates the functional morphology of the bovid distal humerus in isolation due to its increased likelihood of preservation in the fossil record, and the resulting opportunity for a better understanding of the ecomorphology of extinct bovids. A landmark scheme of 30 landmarks was used to capture the 3D distal humerus morphology in 111 extant bovid specimens. We find that the distal humerus has identifiable morphologies associated with body mass, habitat preference and tribe affiliation and that some characteristics are shared between high body mass bovids and those living on hard, flat terrain which is likely due to the high stress on the bone in both cases. We directly apply our findings regarding extant bovids to the extinct alcelaphine bovid, Rusingoryx atopocranion from the mid to late Pleistocene (>33-45 ka) Lake Victoria region of Kenya. This species is known for some peculiar morphologies including a domed cranium with hollow nasal crests, and having small hooves for a bovid of its size. Another interesting aspect of Rusingoryx's skeletal morphology which has not been addressed is an unusual protrusion on the lateral epicondyle of the distal humerus. Despite considerable individual variation in the Rusingoryx specimens, we find evidence to support its historical assignment to the tribe Alcelaphini, and that it likely preferred open grassland habitats, which is consistent with independent reconstructions of the palaeoenvironment. We also provide the most accurate body mass estimate for Rusingoryx to date, based on distal humerus centroid size. Overall, we are able to conclude that the distal humerus in extant bovids is highly informative regarding body mass, habitat preference and tribe, and that this can be applied directly to a fossil taxon with promising results.


Assuntos
Fósseis , Úmero , Animais , Úmero/anatomia & histologia , Fósseis/anatomia & histologia , Imageamento Tridimensional , Ruminantes/anatomia & histologia
3.
J Fish Biol ; 104(2): 387-398, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36600527

RESUMO

Eels have fascinated biologists for centuries due to their amazing long-distance migrations between freshwater habitats and very distant ocean spawning areas. The migratory life histories of the Japanese eel, Anguilla japonica, in the waters of south China are not very clear despite its ecological importance, and the need for fishery regulation and management. In this study, strontium (Sr) and calcium (Ca) microchemical profiles of the otoliths of silver eels were measured by X-ray electron probe microanalysis based on data collected from different habitats (including freshwater and brackish habitats), in the large subtropical Pearl River. The corresponding habitat preference characteristics were further analysed using redundancy analysis (RDA). A total of 195 Japanese eels were collected over 6 years. The collected individuals ranged from 180 to 771 mm in total length and from 8 to 612 g in body weight. Two-dimensional pictures of the Sr:Ca concentrations in otoliths revealed that the A. japonica in the Pearl River are almost entirely river eels, spending the majority of their lives in fresh water without exposure to salt water, while the catadromous migration time has delayed about 1 month in the Pearl River estuary in the past 20 years. RDA analysis further indicated that juveniles and adults preferred water with high salinity and high tide levels. Youth preferred habitats with high river fractals. Our findings contribute to a growing body of evidence showing that the eels are extremely scarce currently and conservation measures against them are imminent, including the protection of brackish and freshwater areas where they live in south China.


Assuntos
Anguilla , Rios , Humanos , Animais , Anguilla/fisiologia , Migração Animal , Cálcio/análise , Ecossistema , Estrôncio/análise , China , Água/análise
4.
Glob Chang Biol ; 29(3): 648-667, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36278894

RESUMO

Anthropogenic climate change is resulting in spatial redistributions of many species. We assessed the potential effects of climate change on an abundant and widely distributed group of diving birds, Eudyptes penguins, which are the main avian consumers in the Southern Ocean in terms of biomass consumption. Despite their abundance, several of these species have undergone population declines over the past century, potentially due to changing oceanography and prey availability over the important winter months. We used light-based geolocation tracking data for 485 individuals deployed between 2006 and 2020 across 10 of the major breeding locations for five taxa of Eudyptes penguins. We used boosted regression tree modelling to quantify post-moult habitat preference for southern rockhopper (E. chrysocome), eastern rockhopper (E. filholi), northern rockhopper (E. moseleyi) and macaroni/royal (E. chrysolophus and E. schlegeli) penguins. We then modelled their redistribution under two climate change scenarios, representative concentration pathways RCP4.5 and RCP8.5 (for the end of the century, 2071-2100). As climate forcings differ regionally, we quantified redistribution in the Atlantic, Central Indian, East Indian, West Pacific and East Pacific regions. We found sea surface temperature and sea surface height to be the most important predictors of current habitat for these penguins; physical features that are changing rapidly in the Southern Ocean. Our results indicated that the less severe RCP4.5 would lead to less habitat loss than the more severe RCP8.5. The five taxa of penguin may experience a general poleward redistribution of their preferred habitat, but with contrasting effects in the (i) change in total area of preferred habitat under climate change (ii) according to geographic region and (iii) the species (macaroni/royal vs. rockhopper populations). Our results provide further understanding on the regional impacts and vulnerability of species to climate change.


Assuntos
Spheniscidae , Humanos , Animais , Melhoramento Vegetal , Ecossistema , Previsões , Mudança Climática , Oceanos e Mares
5.
Ecol Lett ; 25(2): 440-452, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34971478

RESUMO

Ecosystems are linked through spatial flows of organisms and nutrients that impact their biodiversity and regulation. Theory has predominantly studied passive nutrient flows that occur independently of organism movement. Mobile organisms, however, commonly drive nutrient flows across ecosystems through nutrient recycling. Using a meta-ecosystem model where consumers move between ecosystems, we study how consumer recycling and traits related to feeding and sheltering preferences affect species diversity and trophic regulation. We show local effects of recycling can cascade across space, yielding spatially heterogeneous top-down and bottom-up effects. Consumer traits impact the direction and magnitude of these effects by enabling recycling to favour a single ecosystem. Recycling further modifies outcomes of competition between consumer species by creating a positive feedback on the production of one competitor. Our findings suggest spatial interactions between feeding and recycling activities of organisms are key to predicting biodiversity and ecosystem functioning across spatial scales.


Assuntos
Biodiversidade , Ecossistema , Cadeia Alimentar , Nutrientes
6.
J Fish Biol ; 100(1): 175-183, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34697812

RESUMO

The weedy seadragon (Phyllopteryx taeniolatus: Syngnathidae) is an iconic fish endemic to the southern coastal waters of Australia. The authors of this study analysed the habitat preferences and factors influencing microhabitat selection by P. taeniolatus in a population from Kurnell, NSW, Australia. Using field surveys and the resource selection probability function, the authors determined that P. taeniolatus significantly preferred kelp (Ecklonia radiata)-dominated habitat and avoided rock-dominated habitat. They showed P. taeniolatus preferred habitat of between 40% and 80% coverage of Ecklonia, while avoiding areas of <20% cover. Furthermore, across all habitats, mysid prey availability significantly influenced P. taeniolatus habitat selection. The strong dependence of P. taeniolatus on Ecklonia habitat shown in this study was previously untested and highlights that reductions in Ecklonia cover under climate change, or impacts from increasing urbanisation, may render seadragon populations vulnerable to declines.


Assuntos
Kelp , Smegmamorpha , Animais , Ecossistema , Peixes , Urbanização
7.
Exp Appl Acarol ; 87(4): 289-307, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35939244

RESUMO

Punctoribates is one of few genera in Poronota (Acari: Oribatida) containing species with porose areas and species with saccules, the two types of the octotaxic system. These porose organs are the main difference between two morphologically similar species, P. punctum with porose areas and P. zachvatkini with saccules. As the octotaxic system can vary within species, species separation solely based on this trait might be insufficient. To assess the species status of P. zachvatkini, we investigated additional differences from P. punctum by comparing habitat preferences of the two species regarding nature reserves and agricultural landscapes during a field study in the German Eifel region, and by examining Punctoribates material from four large German natural history museums. We also performed scanning electron microscopy (SEM) and a genetic analysis using the D3 marker of the nuclear 28S rDNA gene. In the field study, P. zachvatkini had higher densities in the nature reserves and P. punctum in the agricultural landscapes. Evaluation of the museum material revealed P. punctum occurred more regularly in disturbed sites such as urban, agricultural and post-mining areas compared to P. zachvatkini. Pairwise distances of the 28S D3 genetic marker as well as an additional base pair in P. zachvatkini further support the separation of the two species, and SEM investigations revealed new details regarding the punctulation of P. zachvatkini. The review of the museum material showed that P. zachvatkini already occurred in Germany in 1967 and has a wider distribution than previously known.


Assuntos
Ácaros , Animais , DNA Ribossômico , Ecossistema , Marcadores Genéticos , Alemanha
8.
Zoo Biol ; 41(1): 3-9, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34464479

RESUMO

Research on threatened species in zoos can provide vital information to inform conservation planning and implementation in the field. This is particularly important for rare and cryptic species with behavior patterns that are difficult to observe in the wild. The Critically Endangered golden mantella (Mantella aurantiaca) is an iconic, endemic frog confined to mid-altitude subhumid forest in Moramanga District, Madagascar. Ecological and behavioral data for this highly threatened species are sparse, and conservation work will need to be informed by both in situ and ex situ research on behavior and habitat preferences. This study utilized environmental information gathered in the field to design a system where behavior and microhabitat use could be measured in captivity. Using replicated climatically controlled chambers (the "Froggotrons"), we analysed the 24-h activity profile of the golden mantella in relation to temperature and humidity. Golden mantellas showed a bimodal pattern of activity during the day with much less activity during the night. Frogs kept at warmer temperatures (20-25°C) were more active than those kept under cooler conditions (16-19°C). However, the bimodal pattern was retained under the different temperatures, although the second peak occurred slightly earlier under warmer conditions. Most activity was observed when humidity levels were above 85%, although less than half of the mantellas were active outside leaf microhabitats during peak periods. These findings can inform ongoing field surveys through determining the optimum times of day to either capture or count golden mantellas for further conservation actions.


Assuntos
Animais de Zoológico , Anuros , Comportamento Animal , Animais , Espécies em Perigo de Extinção , Umidade , Temperatura
9.
Urban Ecosyst ; 25(6): 1939-1948, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36159164

RESUMO

How people relate to biodiversity and whether they are supportive of conservation programs and policies has implications on global and local biodiversity conservation efforts. Nature experiences in childhood has been shown to be strongly correlated to positive attitudes towards nature and wildlife in adulthood. In this study, we examined wildlife experience, attitudes and willingness to coexist with 26 vertebrates and invertebrates amongst residents in a highly urbanized tropical city, Singapore. A total of 1004 respondents were surveyed and their childhood nature experience and various socioeconomic variables were obtained. The animals were grouped by their likeability and preferred habitat from the respondents' answers. Three main groups of animals were discerned - unfavorable animals, mammals, and favorable animals. Singapore residents generally had high direct experiences of animals that are common in urban settings, for both favorable and unfavorable animals, such as butterflies, dragonflies, crows and bees, but low direct experiences of forest-dependent wildlife. Animals that were well-liked and acceptable near homes include the common urban ones and some forest-dependent ones, while animals that were disliked included stinging insects (bees and hornets) and reptiles (snakes and water monitors). Structured equation modelling showed that both childhood nature experience and wildlife experience had strong effects on wildlife likeability and habitat preference. The apparent mismatch between greening policies and people's willingness to coexist with wildlife may be problematic as urban development further encroaches on forest habitats, and this study highlights the importance of preserving forest habitats so that young children and adults have opportunities to be exposed to them. Supplementary Information: The online version contains supplementary material available at 10.1007/s11252-022-01280-1.

10.
Mol Phylogenet Evol ; 159: 107087, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33545273

RESUMO

The long-term geological stability of aquatic habitats has been demonstrated to be a determinant in the evolution of macroinvertebrate fauna, with species in running (lotic) waters having lower dispersal abilities, smaller ranges and higher gene flow between populations than species in standing (lentic) environments. Lotic species have been hypothesized to be more specialised, but the diversification dynamics of both habitat types have not been studied in detail. Using a speciose lineage of water beetles we test here whether diversification rates are related to the habitat preference of the species and its consequences on turnover, which we expect to be higher for lotic taxa. Moreover, we tested whether life in lotic environments is acting as an evolutionary dead-end as it is considered an ecological specialisation. We built a comprehensive molecular phylogeny with 473 terminals representing 421 of the 689 known species of the tribe Hydroporini (Coleoptera, Dytiscidae), using a combination of sequences from four mitochondrial and two nuclear genes plus 69 mitogenomes obtained with NGS. We found a general pattern of gradual acceleration of diversification rate with time, with 2-3 significant diversification shifts. However, habitat is not the main factor driving diversification in Hydroporini based on SecSSE analyses. The most recent common ancestor of Hydroporini was reconstructed as a lotic species, with multiple shifts to lentic environments. Most frequent transitions were estimated from lentic and lotic habitats to the category "both", followed by transitions from lotic to lentic and lentic to lotic respectively, although with very similar rates. Contrary to expectations, we found little evidence for differences in diversification dynamics between habitats, with lotic environments clearly not acting as evolutionary dead-ends in Hydroporini.


Assuntos
Evolução Biológica , Besouros/classificação , Ecossistema , Filogenia , Animais , Organismos Aquáticos/genética , Núcleo Celular/genética , Fluxo Gênico , Genes Mitocondriais , Água
11.
J Anim Ecol ; 89(2): 553-564, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31553816

RESUMO

Biodiversity conservation in transformed landscapes is becoming increasingly important. However, most assessments of the value of modified habitats rely heavily on species presence and/or abundance, masking ecological processes such as habitat selection and phenomena like ecological traps, which may render species persistence uncertain. High species richness has been documented in tropical agroforestry systems, but comparisons with native habitat remnants generally lack detailed information on species demography and habitat use. We generated a multi-species, multi-measure framework to evaluate the role of habitat selection in the adaptation of species to transformed landscapes, and demonstrate that its use could affect how we value the contribution different land uses make to biodiversity conservation. We analysed 7 years of capture-mark-recapture and observation data for twelve species of resident birds present in native forest remnants and shade coffee plantations in a mega-diverse region. We assessed whether species behaved adaptively by evaluating the correlation between measures of habitat preference (occurrence, abundance, fidelity, inter-seasonal variance and age) and performance (body condition, muscle, primary moult, breeding and juveniles) in forest and coffee, and generated hypotheses about their role in species persistence. We documented adaptive habitat selection for seven species, non-ideal selection for four and maladaptive selection for one. While many species showed equal preference and/or equal performance in many traits, in general we found more evidence for birds preferring and/or performing better in forest than coffee, although relationships between our indicators and population adaptation need to be studied further before our proposed framework can be applied to more species and landscapes. While shade coffee can act as a biodiversity-friendly matrix providing complementary or supplementary habitat to a wide range of resident bird species, protecting remnants of native vegetation is still of paramount importance for biodiversity conservation in agricultural landscapes.


La conservación de biodiversidad en paisajes transformados es cada vez más importante. Sin embargo, la mayoría de evaluaciones sobre el valor de los hábitats modificados dependen de la presencia y/o abundancia de especies, ocultando procesos ecológicos como la selección de hábitat y fenómenos como las trampas ecológicas, que hacen incierta la persistencia de las especies. Se han documentado altas riquezas en los sistemas agroforestales tropicales pero las comparaciones con remanentes de hábitats nativos generalmente no proveen información detallada sobre demografía y uso de hábitat. Generamos un marco metodológico multi-especies y multi-medidas para evaluar el papel de la selección de hábitat en la adaptación de las especies a los paisajes transformados, y demostramos que su aplicación podría afectar la forma cómo valoramos la contribución que diferentes usos del paisaje hacen a la conservación de la biodiversidad. Analizamos siete años de datos de captura-marca-recaptura y observaciones para doce especies de aves residentes presentes en remanentes de bosque nativo y plantaciones de café con sombra en una región megadiversa. Valoramos si las especies se comportaban de forma adaptativa evaluando la correlación entre medidas de preferencia (ocurrencia, abundancia, fidelidad, varianza inter-estacional y edad) y desempeño (condición corporal, músculo, muda primaria, reproducción y juveniles) en bosques y cafetales, y generamos hipótesis acerca de su papel en la persistencia de especies. Documentamos selección de hábitat adaptativa para siete especies, no-ideal para cuatro y maladaptativa para una. Aunque muchas especies mostraron preferencias y/o desempeño iguales en muchos rasgos, en general encontramos más evidencia de aves prefiriendo y/o desempeñándose mejor en bosques que en cafetales, aunque las relaciones entre nuestros indicadores y la adaptación poblacional deben ser más estudiadas antes de aplicar el marco que proponemos a más especies y paisajes. Aunque los cafetales con sombra pueden actuar como una matriz amigable con la biodiversidad, proveyendo hábitat complementario o suplementario a una gran variedad de aves residentes, para asegurar la conservación de biodiversidad en los paisajes agrícolas es supremamente importante proteger los remanentes de vegetación nativa.


Assuntos
Café , Conservação dos Recursos Naturais , Animais , Biodiversidade , Aves , Ecossistema , Florestas
12.
Oecologia ; 193(2): 261-271, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32281030

RESUMO

For some animals, the habitat which they first experience can influence the type of habitat which they select later in life and, thus, potentially their population distribution and dynamics. However, for many insect herbivores, whose natal habitat may consist of a single hostplant, the consequences of natal hostplant experience remain untested in landscapes relevant to the adult, which may select not only among plants, but among plant patches. As a first step towards understanding how natal hostplant experience shapes patterns of insect feeding damage in landscapes relevant to adults, we conducted partially caged field experiments with diamondback moths that were reared on either mustard or collard plants and then allowed to choose among and within patches of plants that varied in plant density and composition. We predicted that natal hostplant experience would interact with patch size and composition to influence the number of diamondback moth offspring and feeding damage per plant. As predicted, when moths were reared on collards, we found more offspring on and damage to collard plants in four-collard patches than in two-collard patches (i.e., resource concentration), but no difference when moths were reared on mustards. Contrary to predictions, we found no difference in the number of offspring on or damage to mixed plant patches compared with two- or four-collard plant patches regardless of natal hostplant type. Our research suggests that prior hostplant experience has complex consequences for how insects and their feeding damage are distributed in patchy environments and highlights the need for future research in this area.


Assuntos
Mariposas , Animais , Ecossistema , Herbivoria , Larva , Mostardeira
13.
Oecologia ; 194(4): 673-684, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33094381

RESUMO

In plant communities, some mechanisms maintain differences in species' abundances, while other mechanisms promote coexistence. Asymmetry in conspecific negative density dependence (CNDD) and/or habitat preference is hypothesized to shape relative species abundance, whereas community compensatory trends (CCTs) induced by community-level CNDD and heterospecific facilitation are hypothesized to promote coexistence. We use survey data from three 1-ha permanent dynamic plots in a subtropical forest over the course of a decade to find out which of these processes are important and at which life-history stages (the seedling, sapling, and juvenile stages) they exert their effects. CNDD was not related to abundance in any of the life-history stages. Suitable habitats positively influenced plant abundance at all tested life stages, but especially so for juveniles. Community-level CNDD of seedling neighbors was detected at the seedling stage, while heterospecific facilitation was detected across all tested life-history stages. A CCT in seedling survival was detected, but there was no evidence for such trends across the other life-history stages. Altogether, our results suggest that habitat specificity increases the rarity of species, whereas a CCT at the seedling stage, which is likely to be induced by CNDD and heterospecific facilitation, enables such species to maintain their populations.


Assuntos
Ecossistema , Árvores , Florestas , Plântula
14.
BMC Ecol ; 20(1): 5, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992270

RESUMO

BACKGROUND: The availability of preferred habitats determines the spatial and temporal distribution of herbivores in savanna ecosystems. Understanding habitat preference of a targeted wildlife species is crucial for developing effective conservation strategies. Habitat preference of large grazers in connection to grass height and post-fire effect has been debated for the last century. Here, we examined the effects of season, grass height and burning on the habitat preference on Swayne's hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park. Data for seasonal habitat selection were collected using both direct observation along established transect lines and pellet counting using permanently established plots. Every month, we measured grass height commonly preferred by Swayne's hartebeest in grassland habitat. Starting from the first week of burning, we recorded the abundance of Swayne's hartebeest in both burned and unburned grassland patches. RESULTS: From detected pellets, 94.3% were recorded in the grassland habitat indicating that other habitat types are less used despite their extensive cover > 50% of the Park. During wet and early dry seasons, Swayne's hartebeest exclusively preferred grassland habitat. We found that 85.2% (n = 1079) and 85.3% (n = 593) of individuals observed in areas with a grass height below 30 cm during wet and early-dry seasons, respectively; while 70.9% (n = 2288) preferred grass height below 30 cm during the dry season. The density of Swayne's hartebeest in burned grassland area was higher than unburned grassland areas up to 150 days since burning. However, in unburned grassland areas, the density was initially low but showed increasing trend for consecutive days, reaching similar density with burned areas after 150 days since burning. CONCLUSION: Swayne's hartebeest exclusively preferred grassland habitat, particularly during wet and early-dry seasons, shortest available grass height in all seasons and were attracted to burned grassland areas. Our results suggested that fire played an important role in maintaining habitat quality in grassland, and that management should continue using controlled burning as a tool for the conservation of Swayne's hartebeest. However, we remain cautious of our findings given the paucity of information regarding other confounding factors and the absence of long-term data on fire disturbance.


Assuntos
Antílopes , Ecossistema , Animais , Etiópia , Pradaria , Parques Recreativos , Estações do Ano
15.
J Shellfish Res ; 39(3): 563-587, 2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33551544

RESUMO

Oyster habitat restoration seeks to recover lost ecosystem services including increased provisioning of refuge and foraging habitat for fish and invertebrate communities. The goal of this study was to quantify the ecosystem service benefit of habitat provisioning in Ninigret Pond, RI following oyster restoration. We measured four metrics, abundance, biomass, species richness and diversity, as well as isotopic composition in fish and invertebrates collected seasonally from restored oyster, aquaculture, and bare sediment sites, to examine whether the oyster habitat outperformed the bare sediment habitat. Sampling locations were chosen in Foster's Cove north and south, Grassy Point, South Sanctuary, and an Aquaculture lease; each had two restored oyster sites and one bare sediment site. Each site was sampled using a box trap, seine net, shrimp trap, and minnow trap. Oyster habitats had significantly greater metrics than did bare sediment habitats in some comparisons from the box trap and seine net samples. Restored oyster sites at South Sanctuary had lower metric values than the other oyster sites. Metrics from the Aquaculture sites were comparable to the Foster's Cove and Grassy Point restored oyster sites and often outperformed South Sanctuary restored oyster sites. Seasonally, spring and autumn samples tended to have higher abundance and biomass values than summer. Isotopic composition of five species occurring at both restored oyster and bare sediment sites demonstrated some differences in the trophic levels between species but not between habitat types. In Ninigret Pond, fish and invertebrate abundance, biomass, species richness, and diversity benefit from the use of oyster and bare sediment habitats. Coastal zone managers interested in restoring the ecological function of oyster reefs to support fish and invertebrate communities should consider strategically locating restoration projects within the mosaic of structured habitats and monitoring them for selected ecosystem services.

16.
Int J Biometeorol ; 63(3): 269-279, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30680620

RESUMO

Quantifying comfort levels of lions within the Masai Mara National Reserve in Kenya is the main focus of this study. Its discourse delineates step by step the process of quantifying comfort levels of lions within the Mara. Resource-efficient measures for humans in the built environment have long been developed through the creation of passive zones and modulated ventilation. In an analogous manner, new procedures are being adapted for creating optimized microclimates in natural game reserves. This involves CFD (computational fluid dynamics)-inspired landscaping. It is seen that the predicted mean vote (PMV) values-measures of thermal comfort-exceed the expected comfortable ranges suitable for normal functioning of lions in the reserve. This calls for a detailed exploration on sustainable development of this sanctuary. The paper illustrates how modern tools in computational fluid dynamics can be used along with standard ecological models to ascertain the optimal extent of airflow, levels of hydration, and land use pattern changes affecting the prevailing microclimate.


Assuntos
Leões/fisiologia , Microclima , Sensação Térmica , Animais , Hidrodinâmica , Quênia , Parques Recreativos , Plantas , Temperatura
17.
Ecol Lett ; 21(9): 1341-1352, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29938889

RESUMO

Local adaptation to rare habitats is difficult due to gene flow, but can occur if the habitat has higher productivity. Differences in offspring phenotypes have attracted little attention in this context. We model a scenario where the rarer habitat improves offspring's later competitive ability - a carryover effect that operates on top of local adaptation to one or the other habitat type. Assuming localised dispersal, so the offspring tend to settle in similar habitat to the natal type, the superior competitive ability of offspring remaining in the rarer habitat hampers immigration from the majority habitat. This initiates a positive feedback between local adaptation and trait divergence, which can thereafter be reinforced by coevolution with dispersal traits that match ecotype to habitat type. Rarity strengthens selection on dispersal traits and promotes linkage disequilibrium between locally adapted traits and ecotype-habitat matching dispersal. We propose that carryover effects may initiate isolation by ecology.


Assuntos
Ecossistema , Fluxo Gênico , Adaptação Fisiológica , Fenótipo
18.
J Anim Ecol ; 87(3): 774-789, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29430650

RESUMO

The role of interspecific competition for generating patterns in species' distribution is hotly debated and studies taking into account processes occurring at both large and small spatial scales are almost missing. Theoretically, competition between species with overlapping niches should result in divergence of their niches in sympatry to reduce the costs of competition. Many species show a mosaic distribution within sympatric zones, with the syntopic sites occupied by both species, and allotopic sites where only one species occurs. It is unclear whether such mosaics arise as a consequence of competition-driven niche segregation or due to the decline of their abundances towards range edges driven by environmental gradients. If the interspecific competition matters, we should observe (1) a shift in habitat preferences of one or both species between syntopy and allotopy, and (2) between allopatry and allotopy. Moreover, (3) species should show greater divergence in their habitat preferences in allotopy than in allopatry where (4) no differences in habitat preferences may occur. Finally, (5) shifts should be generally greater in the competitively subordinate species than in the dominant species. We used a unique dataset on abundance of two closely related passerine species, the Common Nightingale (Luscinia megarhynchos) and the Thrush Nightingale (Luscinia luscinia), collected across their syntopy, allotopy and allopatry. The predictions were tested within a generalized mixed-effects modelling framework. After accounting for environmental gradients perpendicular to the species' contact zone, we found a strong support for all but one prediction. Habitat preferences of both species shifted markedly between syntopy and allotopy, as well as between allopatry and allotopy. Whereas the species preferred the same habitats in allopatry, their preferences became strikingly different in allotopy where the abundance of the Common Nightingale increased towards dry and warm sites with low coverage of pastures, while the abundance of the Thrush Nightingale showed exactly opposite trends. Fifth prediction was not supported. Our results indicate that the competition between closely related species can result in considerable changes in habitat use across their geographic ranges accompanied with divergence in their habitat preferences in sympatry. Here, the species "escape" from competition to allotopic sites covered by habitats avoided by the competitor. Therefore, we argue that the interspecific competition is an important driver of species' distribution at both large and small spatial scales.


Assuntos
Distribuição Animal , Ecossistema , Aves Canoras/fisiologia , Simpatria , Animais , Polônia
19.
Med Vet Entomol ; 32(1): 48-60, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28842922

RESUMO

Biting midges, Culicoides spp. (Diptera: Ceratopogonidae), are important vectors of viral pathogens. Following the outbreak of bluetongue serotype 8 in Europe between 2006 and 2009, many Culicoides surveillance programmes were initiated to identify vector-active periods, in accordance with European Commission regulation 2007/1266/EC. This study utilized surveillance data from 4 years of continuous light-trapping at 14 sites in Northern Ireland. The number of captured Culicoides varied from none during the vector-free period (December-April) to more than 36 000 per night during peak activity in the summer. The Obsoletus group represented 75% of Culicoides collected and the Pulicaris group represented 21%. A total of 91% of Culicoides were female, of which 42% were parous. Abundance data, sex ratios and parous rates suggested that both the Obsoletus and Pulicaris groups underwent three generations/year. The Obsoletus group was associated with cattle-rearing habitats and woodland, the Impunctatus group was found in habitats related to sheep rearing and the Pulicaris group were associated with both cattle and sheep. Housing did not reduce incursion of female Obsoletus group Culicoides but it did for males and for the Pulicaris group Culicoides. The influence of housing was strongly affected by time of year, probably reflecting the presence of livestock indoors/outdoors.


Assuntos
Distribuição Animal , Ceratopogonidae/fisiologia , Ecossistema , Monitoramento Epidemiológico/veterinária , Abrigo para Animais , Animais , Gado , Irlanda do Norte , Dinâmica Populacional , Vigilância da População , Estações do Ano
20.
Ecotoxicol Environ Saf ; 157: 1-8, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29605640

RESUMO

Despite the potential emissions of heavy metal pollution in Lake Caizi due to extensive agriculture, urban growth and fishing activities, the risk posed by metal concentrations to aquatic environments and human populations has not yet been studied. In this study we compared the concentrations of Hg, As, Pb, Cd, Cr, Cu and Zn in water, sediment, and economic fish species with different habitat preferences and trophic guilds across important fishery areas in Lake Caizi, located on the northern shore of the Yangtze River, Southeast China. The concentrations of Cr in water were found approximately 6 times higher than the safety thresholds established by international legislation. Cr, Zn, As and Cd concentrations in sediments surpassed the background values for Yangtze River basin in Anhui Province. However, all the studied fish species in Lake Caizi had metal concentrations lower than legislation thresholds established by China and international organizations. Heavy metal concentrations were found to be significantly higher in demersal (inhabiting near the sediments) and piscivorous (possessing higher trophic level) fishes than in pelagic/benthopelagic (inhabiting the upper and lower water column) and herbivorous/planktivorous (possessing lower trophic level) fishes. Our finding demonstrated that the metal concentrations in fishes are simultaneously influenced by the habitat and bio-accumulation through the food chain. According to target hazard quotient (THQ) calculations for heavy metal contents in the muscles of fish species, all the determined heavy metals gave THQ values lower than 1, suggesting the inexistence of health risks from the intake of fishes from Lake Caizi.


Assuntos
Peixes/metabolismo , Lagos/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , China , Ecossistema , Monitoramento Ambiental , Cadeia Alimentar , Sedimentos Geológicos/química , Medição de Risco , Água
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