Volatile constituents of Cunila polyantha (Lamiaceae) from Costa Rica. A rich source of menthone

The constituents of the volatile oil of Cunila polyantha from Dota, Costa Rica, were investigated using coupled gas chromatography-mass spectrometry (GC-MS) analyses. Menthone (63%), pulegone (14%), beta-caryophyllene (4.5%) and 3-octanyl acetate (3%) were found to be the major constituents of the volatile oil.     

A phytogeographically significant new species of Jatropha (Euphorbiaceae) from Costa Rica

Jatropha costaricensis is described from Guanacaste, Costa Rica and assigned to sect.Platyphyllae. It is most similar toJ. alamanii of the Isthmus of Tehuantepec in Mexico, and represents part of a secondary Central American radiation of xeric-adapted Euphorbiaceae. Its geographic relationships indicate a formerly more widespread occurrence of a tropical deciduous flora in Mesoamerica, and it is suggested that xeric range disjunctions here and in adjacent South America may be largely due to climaticallyinduced extinction rather than to long-distance dispersal.     

Application of flow cytometry for the determination of minimal inhibitory concentration of several antibacterial agents on Mycoplasma hyopneumoniae

Aim:  In this study, flow cytometry was evaluated for the determination of the minimal inhibitory concentrations (MICs) of nine antibacterial agents (enrofloxacin, ciprofloxacin, oxytetracycline, chloramphenicol, tylosin, lincomycin, gentamycin, spectinomycin and streptomycin) against M. hyopneumoniae .
Methods and Results:  Flow cytometry was able to detect Mycoplasma hyopneumoniae inhibition at 12 h postincubation, whereas the results obtained by the traditional method were only obtained at 48 h, when a visible change in the medium had occurred. At 48 h, both methods gave the same result for eight antibacterial agents, whereas flow cytometry gave slightly higher MIC values for one antibacterial agent (tylosin). This was attributed to the fact that the M. hyopneumoniae growth that had occurred in those tubes was not enough to visibly change the colour of the medium. A good relationship was found between the flow cytometry and the traditional method.
Conclusion:  Flow cytometry was found to be a good method for the determination of antimicrobial MICs in M. hyopneumoniae .
Significance and Impact of the Study:  The flow cytometric method allows the determination of the response of M. hyopneumoniae to each of the antibacterial agents in near real time, and has potential for the identification and study of resistant subpopulations.     

Plant and habitat use by Black‐breasted Pufflegs (Eriocnemis nigrivestis), a critically endangered hummingbird

Black‐breasted Pufflegs (Eriocnemis nigrivestis) are hummingbirds endemic to Ecuador and are considered critically endangered because of their limited distribution, a population estimated at fewer than 1000 individuals, and ongoing habitat degradation. From November 2013 to June 2016, we examined the foraging preferences of these hummingbirds using a combination of direct observations, time‐lapse cameras, and motion‐detection software. We first identified 21 species of ornithophilous plants distributed among five sites in the northwestern flanks of the Pichincha volcano in northwest Ecuador. We then monitored these plant species using time‐lapse cameras and recorded 144 visits by Black‐breasted Pufflegs to seven of the 21 species. Most visits (128 of 144 visits, 89%) were to just two species of plants, Macleania rupestris and Palicourea fuchsioides, the latter of which is also an endemic and threatened species. In addition, Black‐breasted Pufflegs were only observed in the most pristine habitats. Given the potential negative effects of climate change for species in the tropical Andes plus the possible loss and degradation of habitat resulting from human activities, efforts are needed to conserve habitats currently used by Black‐breasted Pufflegs, recover degraded habitats, and connect isolated patches of suitable habitat. Our results concerning species of flowering plants used most by Black‐breasted Pufflegs (P. fuchsioides and M. rupestris) should help guide any habitat restoration initiatives.     

Landscape Simplification Constrains Adult Size in a Native Ground-Nesting Bee

Bees provide critical pollination services to 87% of angiosperm plants; however, the reliability of these services may become threatened as bee populations decline. Agricultural intensification, resulting in the simplification of environments at the landscape scale, greatly changes the quality and quantity of resources available for female bees to provision their offspring. These changes may alter or constrain the tradeoffs in maternal investment allocation between offspring size, number and sex required to maximize fitness. Here we investigate the relationship between landscape scale agricultural intensification and the size and number of individuals within a wild ground nesting bee species, Andrena nasonii. We show that agricultural intensification at the landscape scale was associated with a reduction in the average size of field collected A. nasonii adults in highly agricultural landscapes but not with the number of individuals collected. Small females carried significantly smaller (40%) pollen loads than large females, which is likely to have consequences for subsequent offspring production and fitness. Thus, landscape simplification is likely to constrain allocation of resources to offspring through a reduction in the overall quantity, quality and distribution of resources.     

The distribution of Iberian gypsophilous flora as a criterion for conservation policy

Within the EU territory, gypsum habitats with a peculiar flora are exclusively restricted to the eastern half of the Iberian Peninsula. The Habitats Directive considers the scrublands belonging to the Gypsophiletalia order as priority habitats (habitats 1,520). Although these scrublands do not represent the only kind of vegetation associated with gypsum outcrops, they tend to occur together with other types of communities that grow exclusively on this substrate. As far as vascular flora is concerned, there are some species that grow exclusively on Iberian gypsums and are accordingly included in the Spanish Red List. Besides, given the fragmentary character and punctuated location of these outcrops, the protection of this Iberian habitat and its flora is, therefore, an enormous challenge for any preservation policy. The disjunct distribution of the flora faithfully reflects this geological feature of gypsum areas. Consequently, a proper and detailed knowledge of the distribution of the gypsophilous vascular flora can be very useful in formulating an efficient preservation policy for these habitats. Using the checklist of the Iberian gypsophilous flora, we collected a wide data base with records of distribution arranged into 10 × 10 km UTM grids. For each of the 1,241 grids where at least one gypsophyte was recorded we reckoned a series of parameters in order to determine the priority level of the flora for preservation purposes. These parameters were specific richness, gypsophily level, continuous and discontinuous rarity and endangered level. Our analyses reveal serious gaps in the Spanish network of protected sites with gypsophilous flora, the most important being located in the Hoya de Baza.     

Annual and inter-annual variability of the present climate in northern South America and southern Mesoamerica

Present climate of northwestern South America and the southern Isthmus is detailed in terms of major hydro-climatic controls, supported by evidence from station records, reanalysis data and satellite information. In this tropical region, precipitation is the principal hydro-climatological variable to display great variability. The primary objective is to view the controls that operate at intra-seasonal to inter-decadal time scales. This is a topographical complex region whose climate influences range in provenance from the South Atlantic to the Canadian Prairies, and from the North Atlantic to the Eastern Pacific. The situation is further complicated by interactions and feedbacks, in time and space, between these influences, which are interconnected over various scales. The greatest single control on the annual cycle is the meridional migration of the Inter-tropical Convergence Zone and its pattern of associated trade winds. Consideration of these alone and their interaction with the Cordilleras of the Andes and Central America produce a variety of unimodal and bimodal regimes. Regionally, two low level jet streams, the westerly Choco jet (5°N) and the easterly San Andrés jet (12-14°N), and their seasonal variability, have tremendous significance, as do mesoscale convective storms and mid-latitude cold fronts from both the northern (“nortes”) and southern (“friagems”) hemispheres. There are many examples of hydro-climatological feedbacks within the region. Of these the most notable is the interaction between evaporation over the Amazon, precipitation onto the eastern Andes and streamflow from the headwaters of the Amazon. This is further compounded by the high percentages of recycled precipitation over large areas of the tropics and the potential impacts of anthropogenic modification of the land surface. The El Niño-Southern Oscillation phenomenon (ENSO) is the greatest single cause of interannual variability within the region, yet its effects are not universal in their timing, sign or magnitude. A set of regional physical connections to ENSO are established and their varying local manifestations are viewed in the context of the dominant precipitation generating mechanisms and feedbacks at that location. In addition, some potential impacts of longer run variations within the ocean-atmosphere system of the Atlantic are examined independently and in conjunction with ENSO. This review of the climatic controls and feedbacks in the region provides a spatial and temporal framework within which the highly complex set of factors and their interactions may be interpreted from the past.