scholarly journals Tropical Refuges with Exceptionally High Phylogenetic Diversity Reveal Contrasting Phylogenetic Structures

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Lara Pugliesi ◽  
Alessandro Rapini
Keyword(s):  
Phylogenetic Diversity ◽  
Spatial Scales ◽  
Northeastern Brazil ◽  
Ex Situ ◽  
Habitat Filtering ◽  
Phylogenetic Structure ◽  
Chapada Diamantina ◽  
Limited Dispersal

Loss of phylogenetic diversity (PD) has gained increasing attention in conservation biology. However, PD is not equally distributed in a phylogeny and can be better assessed when species relatedness (phylogenetic structure: PS) is also considered. Here, we investigate PD and PS in two refuges of biodiversity in northeastern Brazil: the Bahia Costal Forest (BCF) in the Atlantic Forest domain and Chapada Diamantina (CD) in the Caatinga domain. We used geographic data of 205 species at two spatial scales and a chronogram of Apocynaceae based on matK sequences to estimate PD and PS. Our results show an exceptionally high PD in both refuges, overdispersed in BCF and clustered in CD, although this difference is less evident or absent for recent relationships, especially at a smaller spatial scale. Overall, PS suggests long-term competitive exclusion under climatic stability, currently balanced by habitat filtering, in BCF, and biome conservatism and limited dispersal leading to in situ diversification and high density of microendemics in CD. The phylogenetically clustered flora in CD, also threatened by climate changes, are naturally more vulnerable than BCF. Therefore, while in situ conservation may ensure protection of biodiversity in BCF, emergency ex situ conservation is strongly recommended in CD.

scholarly journals Propagation of Threatened Nepenthes khasiana: Methods and Precautions

2015 ◽  
Vol 7 (3) ◽  
pp. 313-315
Author(s):  
Jibankumar S. KHURAIJAM ◽  
Rup K. ROY
Keyword(s):  
Plant Species ◽  
Threatened Species ◽  
Ex Situ Conservation ◽  
Ex Situ ◽  
In The Wild ◽  
Propagation Technique ◽  
Subsequent Propagation ◽  
Nepenthes Khasiana

Ex-situ conservation is an important key in the management of rare, endangered and threatened (RET) plant species and its effectiveness depends on several factors. Maintenance of viable germplasm and its subsequent propagation plays an important role in long term conservation of many RET species. Nepenthes khasiana is a rare and gravely threatened species in the wild due to over-collection and other threats. The species needs urgent in-situ and ex-situ conservation. Development of easy to propagate techniques would pave faster multiplication for its use of educational, medicinal and horticultural purpose. In the present paper, successful propagation technique of Nepenthes khasiana through seeds is demonstrated along with detailed information on precautions to be taken during the adoption of the techniques.

scholarly journals The decline and conservation management of the threatened endemic palms of the Mascarene Islands

Oryx ◽  
2002 ◽  
Vol 36 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Mike Maunder ◽  
Wayne Page ◽  
John Mauremootoo ◽  
Richard Payendee ◽  
Yousoof Mungroo ◽  
...  
Keyword(s):  
Large Scale ◽  
Conservation Management ◽  
Conservation Status ◽  
Iucn Red List ◽  
Ex Situ ◽  
Population Fragmentation ◽  
Wild Populations ◽  
Mascarene Islands

Abstract The conservation status of the five genera and 11 species of palm endemic to the Mascarene Islands (Mauritius, La Réunion and Rodriques) are reviewed. All species are threatened with extinction; nine taxa are classified as Critically Endangered and four as Endangered on the 2000 IUCN Red List. Two taxa survive as single wild specimens (Hyophorbe amaricaulis and Dictyosperma album var. conjugatum); an additional seven taxa have wild populations of 100 or fewer. Although the historical phase of large-scale forest clearance has passed, the remaining palm populations in the Mascarenes are under threat from the effects of population fragmentation, invasive plants and animals, and high levels of seed predation that prevent natural regeneration. The advantages of in situ management for the recovery of these palm populations are discussed. Without a long-term conservation programme, utilising both in situ and ex situ management, extinction of wild populations will occur.

scholarly journals Mitigating Batrachochytrium salamandrivorans in Europe

2019 ◽  
Vol 40 (3) ◽  
pp. 265-290 ◽  
Author(s):  
Valarie Thomas ◽  
Yu Wang ◽  
Pascale Van Rooij ◽  
Elin Verbrugghe ◽  
Vojtech Baláž ◽  
...  
Keyword(s):  
Ex Situ Conservation ◽  
Preventive Measures ◽  
Public Awareness ◽  
Ex Situ ◽  
Chytrid Fungus ◽  
Population Declines ◽  
Batrachochytrium Salamandrivorans ◽  
Mitigation Methods

Abstract The infectious chytrid fungus Batrachochytrium salamandrivorans (Bsal) has been responsible for severe population declines of salamander populations in Europe. Serious population declines and loss of urodelan diversity may occur if appropriate action is not taken to mitigate against the further spread and impact of Bsal. We provide an overview of several potential mitigation methods, and describe their possible advantages and limitations. We conclude that long-term, context-dependent, multi-faceted approaches are needed to successfully mitigate adverse effects of Bsal, and that these approaches should be initiated pre-arrival of the pathogen. The establishment of ex situ assurance colonies, or management units, for species threatened with extinction, should be considered as soon as possible. While ex situ conservation and preventive measures aimed at improving biosecurity by limiting amphibian trade may be implemented quickly, major challenges that lie ahead are in designing in situ disease containment and mitigation post-arrival and in increasing public awareness.

scholarly journals Long-term conservation of potato genetic resources: Methods and status of conservation

2019 ◽  
pp. 717-725
Author(s):  
Jane Muthoni ◽  
Hussein Shimelis ◽  
Rob Melis
Keyword(s):  
Genetic Resources ◽  
Slow Growth ◽  
Plant Genetic Resources ◽  
Ex Situ ◽  
Growth Media ◽  
Medium Term ◽  
Natural Habitats

Plant genetic resources (PGRs) play an important role in agriculture, environment protection, cultural property and trade; they need to be conserved. There are two fundamental approaches for the conservation of PGRs: in situ and ex situ. In situ conservation is the conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural surroundings. Ex situ preservation is the storage of seeds or plant materials under artificial conditions to maintain their long term viability and availability for use. Genebanks employ seed storage, field collections of living plants and in vitro storage (tissue culture or cryopreservation) for ex situ preservation of PGR. Storage of orthodox seeds, which are tolerant to low moisture content and low temperatures at appropriate temperature and humidity, is the most convenient ex situ conservation method. Plants that produce recalcitrant seeds or non-viable seeds are conserved in field genebanks as well as in-vitro in slow growth media for short-to-medium term and cryopreservation in liquid nitrogen at -1960C for long-term periods. Cryopreservation is very expensive and needs trained personnel; this could explain why this method is rarely used for conservation of plant genetic resources in most developing countries. Potato tubers are bulky and highly perishable; the crop is generally conserved as clones either in field genebanks (with annual replanting), in-vitro conservation in slow growth media for short-to-medium term and cryopreservation for long term. Field genebanks are expensive to maintain and the crop is exposed to many dangers; hence, cryopreservation is the only feasible method for long term conservation. However, given the high cost of cryopreservation, long-term conservation of potato genetic resources is poorly developed in most resource-poor countries leading to high rates of genetic erosion. This paper looks into the various methods that that can be applied to conserve potato genetic resources and the status of conservation of potatoes in major genebanks and some countries.

In Situ Isotopic Analysis of Uraninite Microstructures from the Oklo-Okélobondo Natural Fission Reactors, Gabon

2002 ◽  
Vol 713 ◽  
Author(s):  
Mostafa Fayek ◽  
Keld A. Jensen ◽  
Rodney C. Ewing ◽  
Lee R. Riciputi
Keyword(s):  
Spatial Resolution ◽  
Spent Nuclear Fuel ◽  
Spatial Scales ◽  
Ionization Mass ◽  
Near Surface ◽  
Chain Reactions ◽  
Isotopic Analyses ◽  
Fission Reactors

ABSTRACTUranium deposits can provide important information on the long-term performance of radioactive waste forms because uraninite (UO2+X) is similar to the UO2 in spent nuclear fuel. The Oklo-Okélobondo U-deposits, Gabon, serve as natural laboratory where the long-term (hundreds to billions of years) migration of uranium and other radionuclides can be studied over large spatial scales (nm to km). The natural fission reactors associated with the Oklo- Okélobondo U-deposits occur over a range of depths (100 to 400 m) and provide a unique opportunity to study the behavior of uraninite in near surface oxidizing environments versus more reducing conditions at depth. Previously, it has been difficult to constrain the timing of interaction between U-rich minerals and post-depositional fluids. These problems are magnified because uraninite is susceptible to alteration, it continuously self-anneals radiation damage, and because these processes are manifested at the nm to μm scale. Uranium, lead and oxygen isotopes can be used to study fluid-uraninite interaction, provided that the analyses are obtained on the micro-scale. Secondary ionization mass spectrometry (SIMS) permits in situ measurement of isotopic ratios with a spatial resolution on the scale of a few μm. Preliminary U-Pb results show that uraninite from all reactor zones are highly discordant with ages aaproaching the timing of fission chain reactions (1945±50 Ma) and resetting events at 1180±47 Ma and 898±46 Ma. Oxygen isotopic analyses show that uraninite from reactors that occur in near surface environments (δ18O= −14.4‰ to −8.5‰) have reacted more extensively with groundwater of meteoric origin relative to reactors located at greater depths (μ18O= −10.2‰ to −7.3‰). This study emphasizes the importance of using in situ high spatial resolution analysis techniques for natural analogue studies.

Population genetics and conservation of the critically endangered Clematis acerifolia (Ranunculaceae)

2005 ◽  
Vol 83 (10) ◽  
pp. 1248-1256 ◽  
Author(s):  
J. López-Pujol ◽  
F.-M. Zhang ◽  
S. Ge
Keyword(s):  
Genetic Diversity ◽  
Population Genetic ◽  
Critically Endangered ◽  
Ex Situ ◽  
Genetic Structuring ◽  
Long Term Storage ◽  
Hardy Weinberg Equilibrium ◽  
Term Storage

Allozyme electrophoresis was used to evaluate the levels of genetic diversity and population genetic structure of the critically endangered Clematis acerifolia Maximowicz (Ranunculaceae), a narrow endemic species in China. On the basis of variation at 19 putative loci in nine populations covering the entire distribution of this species, low values of genetic diversity were detected (P = 20.5%, A = 1.27, and He = 0.072). A significant deficiency of heterozygotes was found in all populations. Most loci showed deviations from the Hardy–Weinberg equilibrium, probably as a result of population genetic structuring. The high genetic divergence among populations (FST = 0.273) can be interpreted as an effect of the extinction of local populations and genetic drift within extant populations, and has probably been enhanced by habitat fragmentation in recent decades. Threats to this species are mainly anthropogenic (road works, construction of holiday resorts, and extraction activities), although stochastic risks cannot be ignored. Therefore, to preserve extant genetic variation of C. acerifolia, in situ strategies, such as the preservation of its habitat or at least the most diverse populations, and ex situ measures, such as the collection and long-term storage of seeds, should be adopted.

scholarly journals Watercress and Water Quality: The Effect of Phenethyl Isothiocyanate on the Mating Behaviour ofGammarus pulex

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Melanie J. Dixon ◽  
Peter J. Shaw
Keyword(s):  
Mating Behaviour ◽  
Sublethal Effect ◽  
Reproductive Behaviour ◽  
Wash Water ◽  
Ex Situ ◽  
Phenethyl Isothiocyanate ◽  
Chalk Streams ◽  
Mean Time

Watercress releases phenethyl isothiocyanate (PEITC) upon wounding as a defence against herbivores. PEITC levels released from watercress farms are elevated due to cropping, washing, and processing and are thought to lead to adverse effects onGammarus pulexin chalk streams. This study elucidates the sublethal effect of PEITC on reproductive behaviour ofG. pulex, employingex situtests to investigate the disruption of precopular pairing under conditions simulatingin situexposure. Mean time to separation of precopular pairs was 89 ± 6 minutes for watercress wash water (1 g watercress per litre water) and 81 ± 15 minutes for pure PEITC (1 μL/L). Re-exposure to watercress wash water to simulate the pulsed operation at a watercress farm did not alter behavioural response. The repeated interruption of reproductive behaviour underin situconditions would impair long-term reproductive success and could explain in part low abundance ofG. pulexdownstream of watercress farms.

scholarly journals <i>In situ</i> observations of turbulent ship wakes and their potential implications for vertical mixing

2020 ◽  
Author(s):  
Amanda T. Nylund ◽  
Lars Arneborg ◽  
Anders Tengberg ◽  
Ulf Mallast ◽  
Ida-Maja Hassellöv
Keyword(s):  
Spatial Scales ◽  
Vertical Mixing ◽  
Turbulent Wake ◽  
Ex Situ ◽  
Landsat 8 ◽  
Spatial And Temporal Scales ◽  
Ship Traffic ◽  
Temporal And Spatial ◽  
Thermal Wake

Abstract. In areas of intensive ship traffic, ships pass every ten minutes. Considering the amount of ship traffic and the fact that global maritime trade is predicted to increase, there is a need to consider all effects shipping has on the marine environment; both pollution and physical disturbances. This paper studies a previously disregarded physical disturbance, namely ship-induced vertical mixing in the turbulent wake. A characterization of the temporal and spatial scales of the turbulent wake is needed to estimate its effect on gas exchange, dispersion of pollutants, and to identify in which areas ship-induced vertical mixing could have an impact on local biogeochemical cycles. There is a lack of field measurements of turbulent wakes of real-size ships, and this study addresses that gap by in situ and ex situ measurements of the depth, width, length, intensity and longevity of the turbulent wake for ~240 ship passages of differently sized ships. A bottom-mounted Acoustic Doppler Current Profiler (ADCP) was placed at 32 m depth below the ship lane outside Gothenburg harbour, and used to measure wake depth and temporal longevity. Thermal satellite images of the Thermal Infrared Sensor (TIRS) onboard Landsat 8 were used to measure thermal wake width and spatial longevity, using satellite scenes from the major ship lane North of Bornholm, Baltic Sea. Automatic Information System (AIS) records from both the investigated areas were used to identify the ships inducing the wakes. The results from the ADCP measurements show median wake depths of ~ 10 m, and several occasions of wakes reaching depths > 18 m. The temporal longevity of the wakes had a median of around 8 min and several passages of > 20 min. The satellite analysis showed a median thermal wake length of 13.7 km, and the longest wake extended over 60 km, which would correspond to a temporal longevity of 1 h 42 min (for a ship speed of 20 knots). The median thermal wake width was 157.5 m. The measurements of the spatial and temporal scales are in line with previous studies, but the deep mixing and extensive longevity presented in this study, has not previously been documented. The results from this study have shown that ship-induced vertical mixing occurs at temporal and spatial scales large enough to imply that this process should be considered when estimating environmental impact from shipping in areas with intense ship traffic. Moreover, the possibility that deep vertical mixing could occur in a highly frequent manner highlights the need of further studies to better characterize the spatial and temporal development of the turbulent wake.

scholarly journals Conservation assessment at a regional level: the study case of 'Delphinium fissum' subsp. 'sordidum' (Ranunculaceae), an endemic Iberian subspecies with disjunct distribution

2019 ◽  
Vol 40 (2) ◽  
pp. 165-175
Author(s):  
Ruben Ramírez-Rodríguez ◽  
Francisco Amich
Keyword(s):  
Ex Situ Conservation ◽  
Conservation Status ◽  
Regional Level ◽  
Ex Situ ◽  
Disjunct Distribution ◽  
Conservation Assessment ◽  
Conservation Values ◽  
Study Case

Delphinium fissum subsp. sordidum is a restricted endemic subspecies whose core distribution is located in the central-western Iberian Peninsula with a disjunct subpopulation in Sierra Mágina (Jaén Province). This article reports a detailed study of its current distribution, population size and structure, and the threats that it faces. Phytosociological analysis shows two main plant communities where D. fissum subsp. sordidum develops: Quercion pyrenaicae and Quercion broteroi. According to the most recent IUCN categories and criteria, the conservation status of D. fissum subsp. sordidum is “Endangered” (EN) in Castile and Leon. We propose the creation of a Plant Micro-Reserve (PMR) in an enclave with high geological, ecological and conservation values. Medium-long term and individualized monitoring programs are required for all distribution range of Delphinium fissum subsp. sordidum. An overall Recovery Plan for the subspecies should be considered and implemented, including in-situ and ex-situ conservation measures that guarantee its protection, conservation and recovery.

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