Wet Vegetation Research Articles

No benefit in using rubber‐coated wire to counter loss of voltage due to tall grass in large carnivore deterring fences

Electric wire enclosures to protect livestock represent one intervention to mitigate negative impacts of large carnivores. However, appropriate fence construction and voltage level in the live wires are crucial to deter carnivores. To ensure that the voltage level remains sufficiently high, maintenances and clearing the wires from tall or growing vegetation is regularly needed. In this study, we investigate the performance of a fence wire coated with conductive rubber, claimed by the supplier not to short circuit and drop in voltage due to contact with e.g. ground and vegetation. We examine the voltage of the rubber‐coated wire during contact with soil, ground, and wet vegetation and observed a voltage loss comparable to that of the standard metal fence wire. Our results imply that the rubber‐coated wire does not perform better than a conventional metal fence wire when in contact with growing grass and other elements that usually short circuit an electric fence.

Revisiting plant hydrological niches: The importance of atmospheric resources for ground‐rooted plants

Abstract Occult precipitation events (fog, dew and light rain) can alter plant water and nutritional status, both directly through the aerial uptake of surface water and nutrients, and indirectly via redistribution of atmospheric resources to the soil. However, current frameworks that explain niche segregation, species interactions and coexistence still consider that ground‐rooted plants obtain resources almost exclusively via root absorption from soil. Here, we expand the plant hydrological niches model to incorporate both soil and atmospheric resource‐axes, thus providing a more complete picture of how ground‐rooted terrestrial plants obtain, remobilise, share and compete for water and soluble nutrients. First, we describe how plants with different water acquisition strategies access directly or indirectly atmospheric resources. Then, we discuss how the use of such resources may promote spatiotemporal niche segregation, contributing to shape species distribution and abundance within plant communities. We illustrate this argument with examples from arid, mesic and wet vegetation types. Finally, we examine how climate and land‐use changes may influence plant hydrological niches, potentially altering community structure. Synthesis. Understanding how available atmospheric resources influences niche segregation in plant communities is a crucial step towards better predictions of species responses (e.g. changes in distribution, abundance and interactions) to climate change.

LAND COVER CHANGE DETECTION NEAR SMALL WATER BODIES BASED ON RGB UAV DATA: CASE STUDY OF THE POND BAROCH, CZECH REPUBLIC

Abstract. Monitoring changes of land cover near water bodies and water bodies themselves represents a part of environment protection and management. The management can be done at the global or local level. The local level requires more detailed data, which can be collected i.e. by means of aircraft or UAV. The paper describes a case study focused on the utilization of UAV-based RGB data to monitor land cover near the pond Baroch, which is located in the Czech Republic, near the city of Pardubice. The area is specific – it is a small pond accompanied by several smaller pools and connecting canals and surrounded by meadows (often watered), reeds, bushes and some trees Used data were collected by authors by in advance planned flights in August, September, October, November, and December 2021. Support Vector Machine, Maximum Likelihood, Random Trees, and Deep Learning are used as methods to process data and detect land cover changes. Manually interpreted data are used as reference data. Because of the nature of the data (only R, G, and B bands), classification into bare land, the water, vegetation, dry vegetation, and wet vegetation classes only was used. Very high heterogeneity of the observed area, availability of RGB bands only, and very high spatial resolution (1,9 cm per pixel) led to isolated cells.

Measurement of the Green Façade Prototype in a Climate Chamber: Impact of Watering Regime on the Surface Temperatures

Green façades with an active water regime and the water flowing through the substrate itself are not common. This system reduces the temperatures and incorporates the evapotranspiration, which could be more effective than by the regular green façades. The use of a double-skin façade with a ventilated air cavity can reduce the heat load, but the evapotranspiration can reduce it even more with additional benefits. Green façades could also serve as a key element for reducing the surface temperatures of the insulated metal panels (IMP), which are mostly used as a façade system for production facilities or factories. In this paper, a prototype of a double-skin façade, which consisted of vegetation board from recycled materials and IMP, is tested in a climate chamber to evaluate the function and benefits of such a combination. The outdoor skin is made from board, the surface of which is covered by the rooted succulent plants. Measurement results are represented as a direct comparison of single sunny day surface temperatures with and without a double-skin (green) façade. The use of the green façade reduces the indoor surface temperature of IMP by 2.8 °C in this measurement. The use of water circulation through the outdoor skin reduces the temperature of the vegetation board by 28 °C. This could have a great impact on the microclimate around the façade. Because of the controlled environment and ventilation system in a climate chamber, it is not possible to investigate the airflow and solar chimney effect within the ventilated cavity. In addition, it is complicated to show the potential of microclimate change caused by the wet vegetation surface. For the mentioned reasons, the need to carry out “in situ” tests on a model wall under the real conditions was indicated.

The influence of surface canopy water on the relationship between L-band backscatter and biophysical variables in agricultural monitoring

The presence of surface water on the canopy affects radar backscatter. However, its influence on the relationship between radar backscatter and crop biophysical parameters has not been investigated. The aim of this study was to quantify the influence of surface canopy water (SCW) on the relationship between L-band radar backscatter and biophysical variables of interest in agricultural monitoring. In this study, we investigated the effect of SCW on the relationship between co- and cross-polarized radar backscatter, cross ratios (VH/VV and HV/HH), and radar vegetation index (RVI) and dry biomass, vegetation water content (VWC), plant height and leaf area index (LAI). In addition, the effect of SCW on estimated vegetation optical depth (VOD) and its relationship with internal VWC was investigated. The analysis was based on data collected during a field experiment in Florida, USA in 2018. A corn field was scanned with a truck-mounted, fully polarimetric, L-band radar along with continuous monitoring of SCW (dew, interception) and soil moisture every 15min for 58 days. In addition, pre-dawn destructive sampling was conducted to measure internal vegetation water content and dry biomass. Results showed that the presence of SCW can increase the radar backscatter up to 2 dB and this effect was lower for cross ratios (CRs) and RVI. The Spearman's rank correlations between radar observables and biophysical parameters were, on average, 0.2 higher for dry vegetation compared to wet vegetation. The estimated VOD from wet vegetation was generally higher than those from dry vegetation, which led to different fitting parameter (so-called b) values in the linear fit between VOD and VWC. The results presented here underscore the importance of considering the influence of SCW on the retrieval of biophysical variables of interest in agricultural monitoring. In particular, they highlight the importance of overpass time, and the impact that daily patterns in dew and interception can have on the retrieval of biophysical variables of interest.

Ecological consequences of Australia's "Black Summer" bushfires: Managing for recovery.

Fire has long been a part of the Australian environment and remains a potent force in shaping the adaptations of species, the dynamics of populations, and the structure of ecological communities. However, the fire regime is changing. Fire seasons are longer, wet vegetation types that do not usually burn are now at risk, and fire intensity and severity are greater than in the recent past. A particularly widespread event occurred in the forest and woodland regions of Australia over the summer of 2019-2020. Termed the "Black Summer" bushfires, remotely sensed data indicate that over 30 million hectares of vegetation were burned, including an unprecedented large area of forest. The extraordinary geographical scale of the Black Summer fires, includingthe intensity and speed of fire spread, has led to widespread concern about the ecological damage that occurred. Recent estimates suggest that almost three billion vertebrates andup to 240 trillion invertebrates were affected by the fires. Fires were experienced in part of the geographical ranges of 832 vertebrate species and 37 threatened ecological communities, with some of these entities feared to be at risk of extinction. Field assessments of ecological recovery have been slowed by COVID-19 restrictions and by a diminution in ecological monitoring capacity that occurred before the last fire season. This paper assesses the dire ecological consequences of the Black Summer bushfires and proposes a series of steps to help achieve recovery of biodiversity and mitigate the effects of future mega-fires. Integr Environ Assess Manag 2021;17:1162-1167. © 2021 SETAC.

Rapid Ecosystem Change at the Southern Limit of the Canadian Arctic, Torngat Mountains National Park

Northern protected areas guard against habitat and species loss but are themselves highly vulnerable to environmental change due to their fixed spatial boundaries. In the low Arctic, Torngat Mountains National Park (TMNP) of Canada, widespread greening has recently occurred alongside warming temperatures and regional declines in caribou. Little is known, however, about how biophysical controls mediate plant responses to climate warming, and available observational data are limited in temporal and spatial scope. In this study, we investigated the drivers of land cover change for the 9700 km2 extent of the park using satellite remote sensing and geostatistical modelling. Random forest classification was used to hindcast and simulate land cover change for four different land cover types from 1985 to 2019 with topographic and surface reflectance imagery (Landsat archive). The resulting land cover maps, in addition to topographic and biotic variables, were then used to predict where future shrub expansion is likely to occur using a binomial regression framework. Land cover hindcasts showed a 235% increase in shrub and a 105% increase in wet vegetation cover from 1985/89 to 2015/19. Shrub cover was highly persistent and displaced wet vegetation in southern, low-elevation areas, whereas wet vegetation expanded to formerly dry, mid-elevations. The predictive model identified both biotic (initial cover class, number of surrounding shrub neighbors), and topographic variables (elevation, latitude, and distance to the coast) as strong predictors of future shrub expansion. A further 51% increase in shrub cover is expected by 2039/43 relative to 2014 reference data. Establishing long-term monitoring plots within TMNP in areas where rapid vegetation change is predicted to occur will help to validate remote sensing observations and will improve our understanding of the consequences of change for biotic and abiotic components of the tundra ecosystem, including important cultural keystone species.

Impacts of Future Climate Changes on Spatio-Temporal Distribution of Terrestrial Ecosystems over China

Understanding the response of terrestrial ecosystems to future climate changes would substantially contribute to the scientific assessment of vegetation–climate interactions. Here, the spatiotemporal distribution and dynamics of vegetation in China were projected and compared based on comprehensive sequential classification system (CSCS) model under representative concentration pathway (RCP) RCP2.6, RCP4.5, and RCP8.5 scenarios, and five sensitivity levels were proposed. The results show that the CSCS model performs well in simulating vegetation distribution. The number of vegetation types would increase from 36 to 40. Frigid–perhumid rain tundra and alpine meadow are the most distributed vegetation types, with an area of more than 78.45 × 104 km2, whereas there are no climate conditions suitable for tropical–extra-arid tropical desert in China. Some plants would benefit from climate changes to a certain extent. Warm temperate–arid warm temperate zone semidesert would expand by more than 1.82% by the 2080s. A continuous expansion of more than 18.81 × 104 km2 and northward shift of more than 124.93 km in tropical forest would occur across all three scenarios. However, some ecosystems would experience inevitable changes. More than 1.33% of cool temperate–extra-arid temperate zone desert would continuously shrink. Five sensitivity levels present an interphase distribution. More extreme scenarios would result in wider ecosystem responses. The evolutionary trend from cold–arid vegetation to warm–wet vegetation is a prominent feature despite the variability in ecosystem responses to climate changes.

Ecological determinants of avian distribution and abundance at Rankin Inlet, Nunavut in the Canadian Arctic

Large areas of the Arctic remain poorly surveyed, creating biological knowledge gaps as scientists and managers grapple with issues of increasing resource extraction and climate change. We modelled spatiotemporal patterns in abundance for avian species in the low Arctic ecosystem near the community of Rankin Inlet, Nunavut, from 2015 to 2017. We employed six habitat covariates, including terrain ruggedness and freshwater cover, and contrasted the influence of elevation with distance from coast, as well as the normalized difference vegetation index (NDVI; a proxy for vegetative productivity) with the normalized difference water index (NDWI; a proxy for vegetation water content). Our results most clearly show the importance of low elevation, large amounts of freshwater and high vegetative productivity for Arctic birds at relatively local scales (<1 km2). Although NDVI more consistently appeared in competitive models of abundance, NDWI was particularly important in predicting abundance for shorebirds, ducks, Tundra Swans (Cygnus columbianus) and Lapland Longspurs (Calcarius lapponicus), demonstrating that it may be a more influential habitat covariate than NDVI for species that frequent habitats with wet vegetation. We also documented apparent shifts in habitat between early and late summer for geese, which were more strongly associated with freshwater later in the season, likely due to the presence of flightless juveniles and moulting adults at that time. Our study illustrates a relatively easy to implement survey methodology for avian species, provides baseline information for an Arctic study area that had not previously been surveyed intensively, and includes species that are underrepresented in previous literature.

Long-Term Changes of Softwood Floodplain Forests—Did the Disappearance of Wet Vegetation Accelerate the Invasion Process?

Objectives: We followed the long-term changes of softwood floodplain forests strongly altered by water regime changes and examine the behaviour of neophytes in this environment. Here we ask: (1) How did the composition of neophyte and native species change? (2) How did the presence of species that prefer wetter conditions change? (3) What traditionally distinguished type of softwood floodplain forests (a wetter one or a more mesophilous one) do neophytes prefer? (4) What environmental factors affect the native species richness and the occurrence and cover of neophytes? Materials and Methods: Historical and recent phytosociological relevés of the association Salicetum albae of the Slovak part of the inland delta of the Danube River were used (177 plots together). For each plot, the number and cover of neophytes and number of native species were measured, and the Shannon-Wiener diversity index, the stand structure (cover of tree, shrub and herb layer) and the mean of Ellenberg indicator values were calculated and compared among time periods. Temporal trends of the soil moisture characterized by indicator values calculated for each plot were determined using a Linear Model. The synoptic table of traditional vegetation types was done to show preferences of neophytes for particular softwood forest types. The effect of site conditions on native species richness and occurrence of neophytes was determined using the Generalized Linear Model. Results: The relative number and cover of neophyte species increased and the absolute number of native species decreased over time; the vegetation of the area has changed from variable hygrophilous and mesophilous to homogenised mesophilous; most non-native species prefer the mesophilous vegetation of the floodplain forests; the wetter parts of the floodplain more successfully resisted invasions. Conclusions: The vegetation of the researched area has considerably changed over time to become less diverse and less hygrophilous, and has more invasive species. To preserve floodplain forests, natural hydrological and connectivity patterns should be adequately protected.

Sedge vegetation of the ‘Major Highlands of Abruzzo’ (Central Italy): updated knowledge after new discoveries

The Major Highlands of Abruzzo is one of the largest and best preserved areas with marsh vegetation in the Apennines. Fairly well known similar plant systems extend from the Umbrian-Marche Apennines to those of the Matese. The marshy and wet vegetation of the large sedge vegetation (Magnocaricetalia) of the “Major Highlands of Abruzzo” is analysed. Other ecotonal or transitional plant communities mainly characterised by smaller sedges are also included in this study. Fifteen vegetation types have been identified, belonging to the following higher syntaxa: (1) Magnocaricetalia (Caricetum gracilis, Caricetum vulpinae, Caricetum vesicariae, Galio palustris-Caricetum buxbaumii ass. nova, Caricetum ripariae, Caricetum distichae, and Caricetum paniculatae); (2) Caricetalia davallianae (Carex fusca community); (3) Eleocharito palustris-Sagittarion sagittifoliae (Eleocharitetum palustris); (4) Potentillion anserinae (Carex panicea and C. tomentosa communities, Ranunculo repentis-Caricetum divisae ass. nova, and Ranunculo acri-Caricetum hirtae); (5) Cynosurion cristati (Carex leporina and C. spicata communities). Nine of these communities are new for the investigated area and seven of them are new for the Abruzzo region. Several of the associations are very rare in Central and Southern Apennines and many endangered plant species are linked to them. Nevertheless, these vegetation types are not sufficiently protected today, especially those outside the National Parks.

Behavioural aspects of microhabitat segregation of different age stages in the wetland land snail Vertigo moulinsiana (Eupulmonata: Vertiginidae) in the laboratory

ABSTRACT This laboratory study investigated behavioural differences between adults and juveniles of the wetland land snail species Vertigo moulinsiana with respect to temperature and humidity. Juveniles of V. moulinsiana, for example, tend to remain within the shaded, humid and cool layer of the litter, while adults usually climb above wet vegetation to a height of over 2 m. Adults are thus exposed to greater variation in temperature and humidity than juveniles. My experiments showed that adults of V. moulinsiana remain active longer than juveniles when subject to high temperature (36 °C) and low relative humidity (RH 30%). Conversely, juveniles stay active longer than adults in high humidity (22 °C, RH 100%). A short period of starvation lengthened the time needed for the juveniles to become active after dormancy, possibly indicating a different response between adults and juveniles to lack of nutritional reserves. These behavioural differences to food availability and the risk of water loss correspond to the microhabitat differences observed between adults and juveniles in the wild.

Habitats of Pleistocene megaherbivores reconstructed from the frozen fauna remains

The Late Pleistocene landscape in northern Eurasia and North America was inhabited by a specific megafaunal complex, which largely disappeared during the Pleistocene/Holocene transition. Vegetation changes are considered as one of the factors responsible for these extinctions, but the structure and composition of the Pleistocene vegetation are still poorly known. Here we complement previous studies by comparing the taxonomic composition of the plant remains found in the gastrointestinal tracts of the frozen carcasses of Pleistocene megaherbivores with the species composition of the current Siberian vegetation. We compiled a dataset of palaeobotanical records from frozen individuals of Pleistocene megaherbivores found in northern Siberia and Beringia and dated to the period from more than 50 kyr BP to 9 kyr BP. We also compiled a dataset of vegetation plots from several regions in Siberia. We analysed the similarity in taxonomic composition of plants between these two datasets using a novel method that accounts for variable taxonomic resolution in palaeobotanical data. For most megaherbivore individuals, plant remains in their gastrointestinal tracts corresponded to tundra, forest and mire vegetation, while they showed low similarity to steppe. This pattern was relatively constant over time, showing no remarkable differences between the Last Glacial Maximum and the periods before and afterwards. This suggests that during the Upper Pleistocene, a mosaic of mesic and wet vegetation types such as tundra with patches of forests and mires was common in northern Siberia and Beringia. In contrast, the steppe was rare to absent in the landscape or underused by the megaherbivores as a pasture since they found enough food in the widespread mesic and wet habitats with more productive vegetation.

Habitat selection and response to playback in wintering Water Rails Rallus aquaticus

ABSTRACTCapsule: Wintering Water Rails Rallus aquaticus prefer small and narrow rivers, with large patches of wet emergent vegetation, and showed active response to playback, especially when they occurred in pairs.Aims: To investigate the habitat preferences and behaviour of Water Rails wintering in riverine ecosystems in eastern Poland.Methods: The study assessed factors driving the occurrence of Water Rails over two winter seasons. Standardized playback stimulation was used to increase bird detection and assess the behavioural response. The mixed model approach allowed the comparison of occupied sites and randomly selected control points, as well as allowing the identification of factors related to the birds’ vocal response.Results: Water Rails occurred on 17–18% of sample points, of which one-third were occupied intensely throughout the whole winter from December to February. Individuals chose places characterised by narrower sections of the riverbed, with a larger cover of wet emergent vegetation. Birds responded to playback with varying levels of aggression; in 56% of cases, Water Rails approached the speaker and produced territorial calls. The level of territorial reaction was higher at sites occupied by two birds, in early winter periods and with higher average temperature.Conclusion: Natural riverine systems, with slow-flowing water and emergent wet vegetation, provide important habitats for Water Rails during the winter season; the species habitat requirements in winter were in general comparable to those of the nesting period. The strong vocal reaction shown, especially at sites occupied by two individuals, indicates the occurrence of strong territorial behaviour also outside the breeding season.

Особливості росту кедра атласького (Cedrus Atlantica (Endl.) Manetti ex Carrière) у лісових культурах Закарпаття

Наведено коротку характеристику кедра атласького та досліджено історію створення насаджень інтродуцента на території держлісфонду державного підприємства "Мукачівське лісомисливське господарство". Встановлено, що оптимальними умовами для культивування кедра атласького в лісових культурах є свіжі й вологі грудові типи лісорослинних умов (D2-3) у передгірській частині Закарпаття до висоти 600 м н.р.м. Визначено показники продуктивності насаджень досліджуваної породи. Встановлено, що в дібровних типах лісорослинних умов кедр атласький на Закарпатті перевершує таксаційні показники аборигенних деревних порід. Порівняльна оцінка лісівничо-таксаційних показників, у розрізі кожної зростаючої породи на досліджуваній ділянці, свідчить, що кедр атласький характеризується кращими показниками розвитку. Запас досліджуваного деревостану, де склад є таким – 8Кда1Яц1См+Клг+Лпд, у 40 річному віці становить 293 м3/га і середній приріст за запасом відповідно – 7,1 м3/га рік. Встановлено, що мішані насадження кедра атласького за середньою висотою та діаметром достовірно вищі, порівняно із чистими деревостанами в однакових ґрунтово-кліматичних умовах Закарпаття. Розпочаті дослідження мають на меті встановлення перспектив використання породи у лісокультурному виробництві регіону, визначення ступеня натуралізації виду та агресивності його поведінки щодо автохтонних деревних видів рослин у корінних типах лісу.

The Pleistocene flora of Bezhan, southeast Albania: early appearance of extant tree species

ABSTRACT The piggyback basin of Bezhan, southeastern Albania, was formed during the late Neogene and contains Pliocene/Pleistocene deposits. These continental deposits consist of marls, siltstones and clays separated by a thin series of lignite-seams alternating with clays (Bezhan formation). We investigated leaf fossils and dispersed pollen from marls of the upper portion of this formation. Fifty-two plant taxa comprising algae, gymnosperms, and angiosperms were recovered. Of these, at least 19% belong to extant species and less than 16% belong to taxa today extinct in western Eurasia. Tsuga is represented by three pollen taxa with affinities to modern Chinese, Japanese, and North American species. Herbaceous taxa indicative of steppe (Artemisia, Amaranthaceae) occur in low quantities (≤1%) suggesting an interglacial setting. Four vegetation units are recognised: Wet riparian and aquatic vegetation, mesic oak forest, dry sub-Mediterranean woodland, and montane conifer forest. A comparison of the Bezhan flora with well-dated Pliocene and Pleistocene floras of Italy suggests a Calabrian (late early Pleistocene) age for the upper unit. This estimate is based on the abundance of extant taxa, the absence of subtropical taxa, and threshold values of particular taxa (Tsuga, Carya). The findings are in agreement with age estimates for extant tree species from molecular studies.

Aspects of the foraging and roosting ecology of the large-eared pied bat (Chalinolobus dwyeri) in the western Blue Mountains, with implications for conservation

The large-eared pied bat (Chalinolobus dwyeri) is listed as vulnerable at both state and federal level, yet little is published on its foraging ecology. Research was conducted to examine its foraging range and habitat (foraging and roosting) preferences. Seven individuals (five female and two male) were radio-tracked in the Blue Mountains, New South Wales, on two separate occasions over a total of nine tracking nights. Females had larger foraging areas than males, but both showed high fidelity to preferred foraging areas. Females roosted separately from males, showing less roost fidelity and roosting at a greater distance from the foraging area. Both males and females roosted in west-facing cliff faces without large caverns. The preferred foraging area included: a sharp grassland–forest border in a western-facing valley, a creek or moist drainage gully with wet vegetation types and day roosts within 700m. At the fine scale, bats foraged along forest edges at mid-to-upper-canopy height and on the outer canopy of individual trees within the forest. Our data suggest that the presence and distance of such habitat requirements should be considered when assessing land management and conservation activities.

Wetlands in flux: looking for the drivers in a central European case

Planet Earth is undergoing significant changes which are driven by natural and anthropogenic factors. However, it is difficult to identify the drivers and their effect on the environment and ecosystems because there are many interdependencies. In this study we present a multi-parameter approach to assess the effect of changes in human-induced and natural drivers on a wetland ecosystem. The study area is one of the most prominent European wetlands: the Biebrza Basin, located in north-eastern Poland. We analysed long-term (ca. 1960–2000) changes in meteorology, hydrology, soil and vegetation, and also conservation history. This approach enabled us to identify interactions between environmental change and management. We found significant trends (1960–2012) indicating climate change: increases in temperature, evapotranspiration and earlier start of spring floods. We identified (1970–2000) a shift towards drier vegetation types after drainage. However, we also found that restoration measures that were implemented have mitigated climate change effects and have led to increases in soil moisture and wetter vegetation types. We conclude that, if carried out sufficiently frequently, the management measures implemented in the Biebrza Basin, which are a combination of different restoration measures (blocking drainage, not clearing aquatic vegetation, bush removal, mowing), can to some extent mitigate the effects of climate change.

Rubiacearum Americanarum Magna Hama Pars XXXVIII: A New Circumscription ofPalicoureasect.Bracteiflorae, an Andean Radiation with Several New Species (Palicoureeae)

Psychotria L. subg. Heteropsychotria Steyerm. (Rubiaceae) has been shown by morphological and molecular analyses to be polyphyletic. Most of its species, including its type, belong to Palicourea Aubl. Some of its species have previously been transferred to Palicourea, and several more are studied and transferred here. The species studied here are classified in a newly circumscribed group that includes the type of Palicourea sect. Bracteiflorae Borhidi and so takes that name but differs in circumscription from it. This new circumscription of Palicourea sect Bracteiflorae includes 51 species of shrubs and small trees found in wet vegetation from southern Mexico and the Antilles to Brazil and Bolivia, and is diagnosed by a combination of stipule, inflorescence, and fruit characters. Its center of diversity is now in the Andean region. Twelve previously described species are newly transferred to Palicourea here, and analysis here clarifies the identity and circumscription of several of these. The 23 species newly described here are documented from Colombia, Ecuador, and Peru. The replacement name Palicourea palenquensis C. M. Taylor is published for the species originally described as Cephaelis gentryi Dwyer. The newly described section Palicourea sect. Egenses C. M. Taylor includes the species of Palicourea sect. Bracteiflorae sensu Borhidi that are excluded from the present circumscription of that section.

Landscape genetics of the Tasmanian devil: implications for spread of an infectious cancer

Emerging infectious diseases are increasingly recognized in species' declines and extinctions. Landscape genetics can be used as a tool to predict disease emergence and spread. The Tasmanian devil is threatened with extinction by a nearly 100% fatal transmissible cancer, which has spread across 95% of the species' geographic range in 20 years. Here, we present a landscape genetic analysis in the last remaining uninfected parts of the Tasmanian devil's geographic range to: describe population genetic structure, characterize genetic diversity, and test the influence of landscape variables on Tasmanian devil gene flow to assess the potential for disease spread. In contrast to previous genetic studies on Tasmanian devils showing evidence for two genetic populations island-wide, our genetic based assignment tests and spatial principal components analyses suggest at least two, and possibly three, populations in a study area that is approximately 15% of the size of the overall species' geographic range. Positive spatial autocorrelation declined at about 40 km, in contrast to 80 km in eastern populations, highlighting the need for range-wide genetic studies. Strong genetic structure was found between devils in the northern part of the study area and those found south of Macquarie Harbour, with weaker structure found between the northeastern and northwestern portion of our study area. Consistent with previous work, we found low overall genetic diversity, likely owing to a combination of founder effects and extreme weather events thousands of years ago that likely caused large-scale population declines. We also found possible signs of recent bottlenecks, perhaps resulting from forest clearing for dairy farming in the central part of the study area. This human disturbance also may have contributed to weak genetic structuring detected between the northeastern and northwestern part of the study area. Individual-based least cost path modeling showed limited influence of landscape variables on gene flow, with weak effects of variation in elevation in the northeast. In the northwest, however, landscape genetic models did not perform better than the null isolation-by-distance model. At the larger spatial scale of the northern part of the study area, elevation and temperatures were negatively correlated with gene flow, consistent with low dispersal suitability of higher elevation habitats that have lower temperatures and dense, wet vegetation. Overall, Tasmanian devils are a highly vagile species for which dispersal and gene flow appear to be influenced little by landscape features, and spread of devil facial tumor disease to the remaining portion of the devil's geographic range seems imminent. Nonetheless, strong genetic structure found between the northern and southern portions of our study area, combined with low densities and limited possible colonization of DFTD from the east suggest there is some time for implementation of management strategies.