Are the adult odonate species found in a protected area different from those present in the surrounding zone? A case study from eastern Amazonia

We studied 30 streams in eastern Amazonia, 17 of which were located within a protected area (PA) and the other 13 in the surrounding zone, with the objective of evaluating the diversity of adult Odonata and if there was a difference between the physical habitat variables of the two environments. We hypothesized that a greater diversity of odonate species would be found in the PA due to a greater complexity of habitats. This hypothesis was rejected, however, due to the greater odonate diversity found in the surrounding zone in comparison with the PA. Differences were also found in the species composition of the two environments. Our results indicate that there are differences between the environmental variables in the areas, and the few alterations observed in the surrounding zone may have contributed to the formation of new conditions and habitats appropriate for species that may have been rare. The PA, despite having reduced species richness and abundance in comparison with the surrounding zone, was nevertheless characterized by a more heterogeneous species composition. A quarter of the species were common to both environments, while 34 % were exclusive to the surrounding zone. In this case, it appears that the combination of the protected area and the surrounding zone, which has a low level of disturbance, conserves a wider range of specialist species than either area on its own. The great challenge in the future is finding a way to identify the disturbance levels that would be acceptable, and to prevent over-exploitation of resources in such areas.     

Are low but statistically significant levels of genetic differentiation in marine fishes ‘biologically meaningful’? A case study of coastal Atlantic cod

A key question in many genetic studies on marine organisms is how to interpret a low but statistically significant level of genetic differentiation. Do such observations reflect a real phenomenon, or are they caused by confounding factors such as unrepresentative sampling or selective forces acting on the marker loci? Further, are low levels of differentiation biologically trivial, or can they represent a meaningful and perhaps important finding? We explored these issues in an empirical study on coastal Atlantic cod, combining temporally replicated genetic samples over a 10‐year period with an extensive capture–mark–recapture study of individual mobility and population size. The genetic analyses revealed a pattern of differentiation between the inner part of the fjord and the open skerries area at the fjord entrance. Overall, genetic differentiation was weak (average F_ST = 0.0037), but nevertheless highly statistical significant and did not depend on particular loci that could be subject to selection. This spatial component dominated over temporal change, and temporal replicates clustered together throughout the 10‐year period. Consistent with genetic results, the majority of the recaptured fish were found close to the point of release, with <1% of recaptured individuals dispersing between the inner fjord and outer skerries. We conclude that low levels of genetic differentiation in this marine fish can indeed be biologically meaningful, corresponding to separate, temporally persistent, local populations. We estimated the genetically effective sizes (N_e) of the two coastal cod populations to 198 and 542 and found a N_e/N (spawner) ratio of 0.14.     

How does the fire regime change after creating a protected area in the Brazilian Cerrado?

Fire is a natural factor maintaining biodiversity and several ecological processes. The Brazilian Cerrado, considered the savanna with the highest biodiversity, is characterized by climatic seasonality, vegetation mosaics and topographic variations that together with fire determine its different plant physiognomies. The Chapada das Mesas National Park (CMNP), located in the south of the state of Maranhão (Brazil), has different savanna plant physiognomies with high ecological potential and archaeological and water wealth. The aim of the present study was to reconstruct the fire history over 28 years for the park and its surroundings (20 km buffer area), endeavouring to understand the impact of the creation of this National Park on its fire regime. Landsat satellite images were used from the TM, ETM + and OLI sensors to map the fire scars, which were identified and vectorized manually. The database created was used to analyze the total annual burned area, burned area percentage, density ignition, mean burn scar area and fire frequency during the mapped period. In total, 86 % of the CMNP was burn at least once between 1990 and 2017, while 72 % of the buffer area was burn. The creation of the park had significant effects on the density ignition when the periods before (1990–2005) and after (2006–2017) its creation were compared, and showed no significant effects on total annual area burned and average burn scar area. Despite the amount of burned area over time did not change significantly between the years before and after, the main change was observed in the fire seasonality after the creation of the park. In the park, 38 % of the area had a frequency of burn areas higher than ten times in the 28-year interval while 13 % of the buffer area was burn more than 10 times. In contrast, 23 % and 15 % had a fire frequency of 2 to 4 times on the buffer and the park respectively. Although the park was created to mitigate the human impacts of fire, the geographic isolation, the current occupation of the park by local populations and the pressure from agricultural expansion in the surroundings are influencing these conservation measures. Understanding the spatial–temporal distribution of fire in protected areas of the Cerrado contributes to improving management, preservation and conservation actions, so that in future studies other factors can be included to better understand the dynamic of fire occurrence in the region of the CMNP and in other protected areas of the Cerrado.     

Phenotypic plasticity or speciation? A case from a clonal marine organism

Background  

Clonal marine organisms exhibit high levels of morphological variation. Morphological differences may be a response to environmental factors but also they can be attributed to accumulated genetic differences due to disruption of gene flow among populations. In this study, we examined the extensive morphological variation (of 14 characters) in natural populations observed in the gorgonian Eunicea flexuosa, a widely distributed Caribbean octocoral. Eco-phenotypic and genetic effects were evaluated by reciprocal transplants of colonies inhabiting opposite ends of the depth gradient and analysis of population genetics of mitochondrial and nuclear genes, respectively.     

Do reef fish assemblages benefit from a marine protected area in the north Pacific coast of Costa Rica?

Environmental Biology of Fishes - Reef fish assemblages under fishing pressure generally exhibit a lower fish biomass, abundance, and size structure, which can be counteracted with the creation of...     

Conservation “identity” and marine protected areas management: A Mediterranean case study

Protection of natural environments sought through management plans varies greatly between countries; characterizing these differences and what motivates them can inform future regional and international conservation efforts. This research builds on previous work addressing the spatial distribution of marine protected areas in the Mediterranean Sea. Particularly, it examines the relationship between a “protection level” (PL) score and a set of variables pertaining to each country's conservation efforts, economic conditions and human impact along the coast using regression analysis. Four sets of models demonstrated country characteristics that correlate with higher protection levels within marine protected areas (MPAs). Certain contextual factors – economic dependence on the marine environment, efforts at terrestrial conservation and greater human impact – were found to be significantly associated with higher PLs among the northern littoral countries of the Mediterranean. Such findings can inform policy makers about where efforts and investments should be directed for marine conservation.     

Are flower-visiting ants mutualists or antagonists? A study in a gynodioecious wild strawberry

Ants are common flower visitors, but their effects on plant reproductive fitness have not often been assessed. Flower-visiting ants were studied to determine whether they are antagonists or mutualists and whether they could influence floral or breeding system evolution in gynodioecious wild strawberry (Fragaria virginiana). Ant and flying pollinator (bees/flies) access to plants was manipulated, and visitation, fruit, and seed set were assessed. Ants visited flowers of hermaphrodites more often than those of females when bees and flies were excluded, but visited the sex morphs equally when they were present. Insect class did not influence fruit or seed set of hermaphrodites. In contrast, ants had both positive and negative effects on seed set in females. Females visited only by ants had 90% of the seed set of those visited only by bees/flies, and their seed set increased with ant visitation. The spatial pattern of seed set, however, suggests that ants may also damage pistils. Lastly, in contrast to bees and flies, ants failed to increase visitation with floral display size, suggesting that ant presence at flowers could reduce selection on this attractive trait. Findings suggest that when in high abundance, flower-visiting ants could affect breeding system and floral evolution in this gynodioecious plant.     

Are important bird areas and special protected areas enough for conservation?: the case of Bonelli’s eagle in a Mediterranean area

The Bonelli’s eagle (BE) is considered by the European Union as a high-priority species for conservation in the Valencian Community (East of Spain). However, in 2006 the European Union opened a legal procedure against the Spanish Kingdom, accused of lacking of an adequate network of special protected areas (SPAs) to preserve the BE in the region. Here we evaluate whether important bird areas (IBAs) and SPAs network is enough to preserve this species, on the basis of a thorough analysis of habitat preferences. A GAP analysis is performed to conduct a revision of current SPAs and BirdLife proposed IBAs. Our results suggest that the current network of SPAs becomes insufficient to protect the BE. The IBAs network, although improves the current network of SPAs, increasing the percentage of BE potential habitat included, also results inadequate. We propose a new SPAs network according to the potential suitable habitat for the species. Given the trade-off between financial investment and the conservation of biodiversity, we propose to maximize the surface of potential habitat included in the protected network minimizing the surface of the region that would be necessary to protect, thus avoiding an unnecessary expense and otherwise unrealistic results.     

Can the structure of a riparian forest remnant influence stream water quality? A tropical case study

In rural areas, riparian forest remnants can be very important for the maintenance and improvement of stream water quality. We evaluated if a forest remnant influenced stream water quality, and if these results were influenced by forest structure. We sampled reaches from 140 m upstream of the remnant edge until 600 m within the forest remnant. Electric conductivity (EC) and ammonium concentrations decreased as the stream flowed through the remnant, whereas dissolved oxygen, total phosphorus (P), total dissolved P, organic P, and silicate concentrations increased along the remnant. Variation in forest structure was due to a gradient in forest stratification versus tree height and diameter at breast height, and a gradient in tree density versus basal area. More stratified parts of the forest, with smaller trees, resulted in lower EC values and concentrations of total nitrogen and nitrite, whereas higher density of trees resulted in lower levels of total and dissolved P, creating heterogeneity at very local scales. The overall mean influence of this riparian forest remnant improved stream water quality, suggesting that forest remnants have local effects that can be important when managing stream water quality at larger spatial scales.     

Terrestrial or marine species distribution model: Why not both? A case study with seabirds

Species reliant on both the terrestrial and marine realms present a challenge for conventional species distribution models (SDMs). For such species, standard single‐realm SDMs may omit key information that could result in decreased model accuracy and performance. Existing approaches to habitat suitability modeling typically do not effectively combine information from multiple realms; this methodological gap can ultimately hamper management efforts for groups such as seabirds, seals, and turtles. This study, for the first time, jointly incorporates both terrestrial information and marine information into a single species distribution model framework. We do this by sampling nearby marine conditions for a given terrestrial point and vice versa using parameters set by each species’ mean maximum foraging distance and then use standard SDM methods to generate habitat suitability predictions; therefore, our method does not rely on post hoc combination of several different models. Using three seabird species with very different ecologies, we investigate whether this new multi‐realm approach can improve our ability to identify suitable habitats for these species. Results show that incorporating terrestrial information into marine SDMs, or vice versa, generally improves model performance, sometimes drastically. However, there is considerable variability between species in the level of improvement as well as in the particular method that produces the most improvement. Our approach provides a repeatable and transparent method to combine information from multiple ecological realms in a single SDM framework. Important advantages over existing solutions include the opportunity to, firstly, easily combine terrestrial and marine information for species that forage large distances inland or out to sea and, secondly, consider interactions between terrestrial and marine variables.     

Records of bentfin devil ray,Mobula thurstoni,in a marine protected area in Brazilian Equatorial Atlantic: implications for the species’ distribution and local conservation strategies

Environmental Biology of Fishes - The bentfin devil ray (Mobula thurstoni) is a migratory elasmobranch species with a wide distribution range. Despite the recent increase in mobulid research,...     

Are biodiversity patterns of saproxylic beetles shaped by habitat limitation or dispersal limitation? A case study in unfragmented montane forests

Understanding the processes that shape biodiversity patterns is essential for ecosystem management and conservation. Local environmental conditions are often good predictors of species distribution and variations in habitat quality usually positively correlate to species richness. However, beside habitat limitation, species presence-absence may be constrained by dispersal limitation. We tested the relative importance of both limitations on saproxylic beetle diversity, using forest continuity as a surrogate for dispersal limitation and stand maturity as a surrogate for habitat limitation. Forest continuity relies on the maintenance of a forest cover over time, while stand maturity results in the presence of old-growth habitat features. Forty montane beech-fir forests in the French pre-Alps were sampled, under a balanced sampling design in which forest continuity and stand maturity were crossed. A total of 307 saproxylic beetle species were captured using flight-interception traps and Winkler–Berlese extractors. We explored the response of low- versus high-dispersal species groups to forest continuity and stand maturity. Saproxylic beetle diversity increased significantly with stand maturity and was mostly influenced by variables related to deadwood diversity at the stand scale and suitable habitat availability at the landscape scale. Surprisingly, no evidence of dispersal limitation was found, as diversity patterns were not influenced by forest continuity and associated variables, even for low-dispersal species. Our study demonstrates that in an unfragmented forest landscape, saproxylic beetles are able to colonize recent forests, as long as local deadwood resources are sufficiently diversified (e.g. tree species, position, diameter and/or decay stage).     

Does climate influence assemblages of anurans and lizards in a coastal area of north-eastern Brazil?

Environmental factors influence diverse assemblage features such as species abundances, richness, and nestedness. Amphibians and reptiles play important roles in terrestrial ecosystems, but there is still a lack of information about the assemblages of these animals in many regions. In this study, we aimed to understand how environmental factors influence the anurans and lizards assemblages from São Gonçalo do Amarante, Ceará, Brazil. Herpetofauna samplings were performed monthly in São Gonçalo do Amarante from January 2008 to May 2009, excluding April 2008. We sampled animals (anurans and lizards) using pitfall traps and active searches. The abundance and richness of lizards were positively related to temperature and negatively related to precipitation. Anuran assemblage was not influenced by precipitation, but its abundance was negatively influenced by temperature. Temperature generated a nested pattern in the lizard assemblage, but precipitation did not produce this pattern in anurans. Finally, our results reinforce the importance of environmental factors, mainly temperature, in structuring assemblages of anurans and lizards.     

Are wives and daughters disadvantaged in polygynous households? A case study of the Arsi Oromo of Ethiopia

Whether polygyny is harmful for women and their children is a long-standing question in anthropology. Few studies, however, have explored whether the effect of polygyny varies for women of different wife order, and whether there are different outcomes for their sons and daughters. Because males have higher reproductive variance, especially when they are allowed to take multiple wives, parents may have higher fitness returns from investing in sons over daughters in polygynous households. Moreover, previous studies have found that first wives and their children are advantaged over monogamous and second order wives (who marry into unions later). Here we test the predictions that children of first wives will have an advantage over children to monogamous or second wives, and that sex-biased investment will be strongest among first wives. Using data from the Arsi Oromo of Ethiopia (n ~ 6200 children) we test whether associations with mother's wife order extend beyond childhood into adulthood by examining simultaneously child survival, education and age at marriage. We find that polygynous first wives have no child survival disadvantage, first wives' sons benefit in terms of longer education and daughters have an earlier age at marriage than daughters of monogamous women. Second wives have lower child survival than monogamous women, but surviving children experience advantages in later life outcomes, particularly marriage. These findings challenge the view that polygynous women are always doing the ‘best of a bad job’. Rather, our results suggest that via their surviving sons and daughters there may be long-term benefits for some polygynous women.     

Daily variation of marine cladoceran densities in a tropical bay – Brazil

This contribution presents the daily variation of marine cladoceran densities in Guanabara Bay. The samples were obtained by vertical tows with a 200 m mesh-size conical net at different times over a 4-day period in September, 1995. Penilia avirostris was the most common species, followed by Evadne tergestina and E. spinifera. These organisms presented higher densities at nightfall. Physical factors like tide and light are responsible for the highest densities. High tide and nightfall time are requested conditions for the P. avirostris and E. tergestina abundance. Temperature and salinity appear to have no relation with cladoceran densities.     

Are landscape attributes a useful shortcut for classifying vegetation in the tropics? A case study of La Amistad International Park

Effective vegetation classification schemes identify the processes determining species assemblages and support the management of protected areas. They can also provide a framework for ecological research. In the tropics, elevation‐based classifications dominate over alternatives such as river catchments. Given the existence of floristic data for many localities, we ask how useful floristic data are for developing classification schemes in species‐rich tropical landscapes and whether floristic data provide support for classification by river catchment. We analyzed the distribution of vascular plant species within 141 plots across an elevation gradient of 130 to 3200 m asl within La Amistad National Park. We tested the hypothesis that river catchment, combined with elevation, explains much of the variation in species composition. We found that annual mean temperature, elevation, and river catchment variables best explained the variation within local species communities. However, only plots in high‐elevation oak forest and Páramo were distinct from those in low‐ and mid‐elevation zones. Beta diversity did not significantly differ in plots grouped by elevation zones, except for low‐elevation forest, although it did differ between river catchments. None of the analyses identified discrete vegetation assemblages within mid‐elevation (700–2600 m asl) plots. Our analysis supports the hypothesis that river catchment can be an alternative means for classifying tropical forest assemblages in conservation settings.     

Regional hotspots of butterfly diversity in a protected area: Are they indicators of unique assemblages and areas with more species of conservation concern?

The implementation of biodiversity studies to set conservation priorities assumes that the different criteria used in prioritisation are correlated. Based on butterfly data, we examined whether high total diversity (species density and richness), unique species assemblages, and high numbers of different categories of Species of European Conservation Concern (SPEC) were co-located in the same habitats in the Picos de Europa National Park, Spain. Species density (number of species per sample) declined with elevation and was significantly higher in Genista shrublands on southern slopes (Southern Genista shrubland). We found unique species assemblages for Southern Genista shrublands, heathlands, mown meadows and subalpine meadows, whereas Genista shrubland on northern slopes (Northern Genista shrubland) and pastures were occupied by more habitat generalist species. We also found an effect of elevation on species composition. Species with global distributions concentrated in Europe (SPECs 4b) tended to be associated with Southern Genista shrubland, whereas species with global distributions restricted to Europe (SPECs 4a) were associated with higher elevations. Thus, we suggest a higher conservation value for butterfly assemblages located both on Southern Genista shrublands and at high elevations as they contain unique assemblages with a higher number of SPECs. By comparing our data with a previous study on carabid beetles, we found a low coincidence between butterflies and beetles for habitats with high species diversity and unique assemblages. Our study suggests that preserving areas in the landscape supporting higher butterfly diversity only partially preserves those species of greater conservation concern, and that butterflies cannot be used as a reliable indicator of other priority taxa for conservation, such as carabid beetles.