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 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.

scholarly journals Demographic and genetic factors in the recovery or demise ofex situpopulations following a severe bottleneck in fifteen species of Hawaiian tree snails

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1406 ◽  
Author(s):  
Melissa R. Price ◽  
David Sischo ◽  
Mark-Anthony Pascua ◽  
Michael G. Hadfield
Keyword(s):  
Life History Traits ◽  
Human Impacts ◽  
Ex Situ ◽  
Wild Populations ◽  
Captive Populations ◽  
Introduced Predators ◽  
In Captivity ◽  
Term Data

Wild populations of endangered Hawaiian tree snails have declined precipitously over the last century due to introduced predators and other human impacts. Life history traits, such as very low fecundity (<5 offspring per year across taxa) and maturity at approximately four years of age have made recovery difficult. Conservation efforts such asin situpredator-free enclosures may increase survival to maturity by protecting offspring from predation, but no long-term data existed prior to this study demonstrating the demographic and genetic parameters necessary to maintain populations within those enclosures. We evaluated over 20 years of evidence for the dynamics of survival and extinction in captiveex situpopulations of Hawaiian tree snails established from wild-collected individuals. From 1991 to 2006, small numbers of snails (<15) from fifteen species were collected from the wild to initiate captive-reared populations as a hedge against extinction. This small number of founders resulted in a severe bottleneck in each of the captive-reared populations. We identified key demographic parameters that predicted population recovery from this bottleneck. Species with captive populations that produced between two and four offspring per adult per year and had 20–50% of those offspring survive to maturity recovered to numbers above 100 individuals, and maintained viable populations following a decline that occurred between 2009 and 2014. Those populations that had less than two offspring per adult per year and less than 20% survival to maturity did not reach 100 individuals in captivity, and many of these populations died out during the recent decline. We suggest that small reductions in fitness may contribute to extirpation in taxa with inherently low fecundity, by keeping populations below a threshold number essential to long-term recovery. Futureex situpopulations should be founded with no less than 15 adults, and maintained in conditions closely approximating the temperature and humidity of source locations to optimize fitness. Permanent translocations of wild populations for conservation purposes will be more likely to succeed with greater than 100 adults, and should be limited to locations with a similar climate to source locations.

scholarly journals Conservation status of eleven wild bean (Phaseolus spp. Fabaceae) species in northeastern Mexico

2019 ◽  
Vol 10 (2) ◽  
pp. 417-429
Author(s):  
Alma Delia Baez-González ◽  
Efraín Acosta-Díaz ◽  
José Saúl Padilla-Ramírez ◽  
Isidro H. Almeyda-León ◽  
Francisco Zavala-García
Keyword(s):  
Conservation Status ◽  
Ex Situ ◽  
Current Conservation ◽  
Wild Bean ◽  
Natural Factors ◽  
Northeastern Mexico ◽  
Not At Risk ◽  
Phaseolus Species

Rare and endemic plants, such as the wild species of Phaseolus (Fabaceae) in northeastern Mexico, deserve high priority in conservation efforts because of their uniqueness and usefulness as plant genetic resource. This is particularly important because during the last decades, some of these species have become endangered because of anthropogenic and natural factors. The study aimed to determine the current conservation status of 11 reported wild bean species in northeastern Mexico, using wild bean data from 77 expeditions to the states of Nuevo León and Tamaulipas during the period 1869-2013.The conservation status of the different species was determined according to the Official Mexican Standard NOM-059-SEMARNAT-2010. The categories of risk were based on four indicators: amplitude of distribution, habitat status, biological vulnerability and impact of human activity. The following eight wild Phaseolus species are not at risk of extinction: P. albiflorus, P. glabellus, P. leptostachyus, P. maculatifolius, P. neglectus, P. pedicellatus, P. vulgaris and P. zimapanensis. On the other hand, P. altimontanus Freytag & Debouck is categorized as threatened; P. novoleonensis Debouck, in danger of extinction; and P. plagiocylix Harms, possibly extinct.  Current in situ and ex situ conservation programs need to be strengthened and expanded for the medium- and long-term protection of wild bean species in northeastern Mexico.

scholarly journals Global soil moisture data derived through machine learning trained with in-situ measurements

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sungmin O. ◽  
Rene Orth
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Large Scale ◽  
Short Term Memory ◽  
Temporal Dynamics ◽  
Soil Moisture Data ◽  
Wide Range ◽  
Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

In Situ Tests on Creep Behavior of Rock Mass with Joint or Shearing Zone in Foundation of Large-Scale Hydroelectric Projects

2004 ◽  
Vol 261-263 ◽  
pp. 1097-1102 ◽  
Author(s):  
Jian Liu ◽  
Xia Ting Feng ◽  
Xiu Li Ding ◽  
Huo Ming Zhou
Keyword(s):  
Rock Mass ◽  
Creep Behavior ◽  
Large Scale ◽  
Time Dependent ◽  
Three Gorges Project ◽  
Three Gorges ◽  
The Three Gorges ◽  
The Three Gorges Project

The time-dependent behavior of rock mass, which is generally governed by joints and shearing zones, is of great significance for engineering design and prediction of long-term deformation and stability. In situ creep test is a more effective method than laboratory test in characterizing the creep behavior of rock mass with joint or shearing zone due to the complexity of field conditions. A series of in situ creep tests on granite with joint at the shiplock area of the Three-Gorges Project and basalt with shearing zone at the right abutment of the Xiluodu Project were performed in this study. Based on the test results, the stress-displacement-time responses of the joints and basalt are analyzed, and their time-dependent constitutive model and model coefficients are given, which is crucial for the design to prevent the creep deformations of rock masses from causing the failure of the operation of the shiplock gate at the Three-Gorges Project and long-term stability of the Xiluodu arc dam.

scholarly journals Evaluating Machine Learning and Geostatistical Methods for Spatial Gap-filling of Monthly ESA CCI Soil Moisture in China

2021 ◽  
Vol 13 (14) ◽  
pp. 2848
Author(s):  
Hao Sun ◽  
Qian Xu
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Water Resource Management ◽  
Large Scale ◽  
Gap Filling ◽  
Spatial Continuity ◽  
Study Results ◽  
Data Gaps

Obtaining large-scale, long-term, and spatial continuous soil moisture (SM) data is crucial for climate change, hydrology, and water resource management, etc. ESA CCI SM is such a large-scale and long-term SM (longer than 40 years until now). However, there exist data gaps, especially for the area of China, due to the limitations in remote sensing of SM such as complex topography, human-induced radio frequency interference (RFI), and vegetation disturbances, etc. The data gaps make the CCI SM data cannot achieve spatial continuity, which entails the study of gap-filling methods. In order to develop suitable methods to fill the gaps of CCI SM in the whole area of China, we compared typical Machine Learning (ML) methods, including Random Forest method (RF), Feedforward Neural Network method (FNN), and Generalized Linear Model (GLM) with a geostatistical method, i.e., Ordinary Kriging (OK) in this study. More than 30 years of passive–active combined CCI SM from 1982 to 2018 and other biophysical variables such as Normalized Difference Vegetation Index (NDVI), precipitation, air temperature, Digital Elevation Model (DEM), soil type, and in situ SM from International Soil Moisture Network (ISMN) were utilized in this study. Results indicated that: 1) the data gap of CCI SM is frequent in China, which is found not only in cold seasons and areas but also in warm seasons and areas. The ratio of gap pixel numbers to the whole pixel numbers can be greater than 80%, and its average is around 40%. 2) ML methods can fill the gaps of CCI SM all up. Among the ML methods, RF had the best performance in fitting the relationship between CCI SM and biophysical variables. 3) Over simulated gap areas, RF had a comparable performance with OK, and they outperformed the FNN and GLM methods greatly. 4) Over in situ SM networks, RF achieved better performance than the OK method. 5) We also explored various strategies for gap-filling CCI SM. Results demonstrated that the strategy of constructing a monthly model with one RF for simulating monthly average SM and another RF for simulating monthly SM disturbance achieved the best performance. Such strategy combining with the ML method such as the RF is suggested in this study for filling the gaps of CCI SM in China.

scholarly journals ENVIRONMENTAL POLLUTION BY WASTEWATER FROM BROWN COAL PROCESSING ¬ A REMEDIATION CASE STUDY IN GERMANY

2014 ◽  
Vol 22 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Arndt Wiessner ◽  
Jochen A. Müller ◽  
Peter Kuschk ◽  
Uwe Kappelmeyer ◽  
Matthias Kästner ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Large Scale ◽  
Pilot Scale ◽  
Wastewater Disposal ◽  
Interdisciplinary Approaches ◽  
Phenolic Wastewater ◽  
Term Monitoring

The large scale of the contamination by the former carbo-chemical industry in Germany requires new and often interdisciplinary approaches for performing an economically sustainable remediation. For example, a highly toxic and dark-colored phenolic wastewater from a lignite pyrolysis factory was filled into a former open-cast pit, forming a large wastewater disposal pond. This caused an extensive environmental pollution, calling for an ecologically and economically acceptable strategy for remediation. Laboratory-scale investigations and pilot-scale tests were carried out. The result was the development of a strategy for an implementation of full-scale enhanced in situ natural attenuation on the basis of separate habitats in a meromictic pond. Long-term monitoring of the chemical and biological dynamics of the pond demonstrates the metamorphosis of a former highly polluted industrial waste deposition into a nature-integrated ecosystem with reduced danger for the environment, and confirmed the strategy for the chosen remediation management.

scholarly journals Sustainable Use of Fig Species Provides Nutrition and Medicine for Ethnic Minority Communities in the Southern Shan State of Myanmar

2020 ◽  
Author(s):  
Aye Mya Mon ◽  
Yinxian Shi ◽  
Pyae Phyo Hein ◽  
Thaung Naing Oo ◽  
Cory W. Whitney ◽  
...  
Keyword(s):  
Ethnic Groups ◽  
Conservation Status ◽  
Sustainable Use ◽  
Ex Situ ◽  
Conservation Practices ◽  
Use Value ◽  
Ethnobotanical Knowledge ◽  
Structured Interviews ◽  
Tropical Regions

Abstract Background: Fig trees are ecological keystone species in many tropical regions and play important roles in the spirituality, nutrition and health for many rural communities. Although the tropical forests in Myanmar contain many fig species, little ethnobotanical knowledge on their uses has been recorded.Information about the uses and conservation related actions of figswould be helpful in development ofstrategic policy for sustainable use and biodiversity conservation of the country. We showcase the rich ethnobotanical knowledge as well as the variety of collection and conservation practices related to figs among five ethnic groups in Southern Shan State. Methods: We performed both key informant and semi-structured interviews with 114 informants from five ethnic groups. Their uses for figs were categorized according to local practices and recipes. Informants were asked about trends in conservation status over the past 10 years and any conservation related customs and practices. Data were analyzed quantitatively by use report (UR) and use value (UV). Results: Informants reported the uses of eight fig species (Ficusauricularta，F.concinna, F. geniculata，F. hispida, F. racemosa, F. religiosa，F. semicordata, and F. virens).F. geniculata and F. virens were most useful (UR = 228) and were used by all five ethnic groups, corresponding to a high use value (UV = 2). Treatments for 16 diseases were reported from seven species. Household consumption, economic, and sacred uses were accompanied by sustainable practices of harvest and protection. Traditional taboos, in situ and ex situ conservation were practiced especially for highly demanded species (F. geniculata and F. virens), and the sacred fig F. religiosa.Conclusion: Findings suggest that figs are useful for nutrition (all informants) and medicine (13.16% of the informants) in the study area. Traditional taboos, in situ and ex situ conservation practices help to maintain sustainable utilization of locally important figs. This is an early contribution to the traditional knowledge of edible figs. Although similar uses have been reported in neighboring countries for seven of the fig species, the ethnobotanical use of F. concinna is novel.

scholarly journals Minimum time required to detect population trends: the need for long-term monitoring programs

2018 ◽  
Author(s):  
Easton R White
Keyword(s):  
Time Series ◽  
Statistical Power ◽  
Conservation Status ◽  
Species Conservation ◽  
Population Data ◽  
Iucn Red List ◽  
Series Length ◽  
Large Variability ◽  
Monitoring Programs

Long-term time series are necessary to better understand population dynamics, assess species' conservation status, and make management decisions. However, population data are often expensive, requiring a lot of time and resources. What is the minimum population time series length required to detect significant trends in abundance? I first present an overview of the theory and past work that has tried to address this question. As a test of these approaches, I then examine 822 populations of vertebrate species. I show that 72% of time series required at least 10 years of continuous monitoring in order to achieve a high level of statistical power. However, the large variability between populations casts doubt on commonly used simple rules of thumb, like those employed by the IUCN Red List. I argue that statistical power needs to be considered more often in monitoring programs. Short time series are likely under-powered and potentially misleading.

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.

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