scholarly journals Monitoring and conservation of the rare orchid Didimoplexis verrucosa in the face of change

Bothalia ◽  
2021 ◽  
Vol 51 (2) ◽  
Author(s):  
T.H.C. Mostert ◽  
R.E. Mostert
Keyword(s):  
Conservation Status ◽  
Management Strategies ◽  
Population Monitoring ◽  
Environmental Indicators ◽  
Habitat Characteristics ◽  
Similar Degree ◽  
Suitable Habitat ◽  
Individual Plant ◽  
Accurate Identification ◽  
Term Survival

Abstract Background: Didymoplexis verrucosa is a cryptic leafless saprophytic ground orchid (~70 mm tall) growing on the coastal forest floors of southern Zululand and classified as Vulnerable (D2). As part of a population monitoring programme, 960 man-hours of species specific searching over five consecutive flowering seasons were conducted, yielding only one individual plant. Objective: The aim of this study was to increase detection rate by developing a profile of environmental indicators for the accurate identification of suitable habitat. Methods: A detailed description of suitable habitat was compiled based on the Braun-Blanquet approach. Results: The results showed that key attributes shared by localities include similar topographic position in the landscape, hydrology, soils, vegetation composition and structure, forest age, leaf-litter composition of the forest floor, the co-occurrence of Isoglossa woodii, and a similar degree of protection from sunlight, wind and desiccation. Significance of the findings: This profile of essential habitat characteristics can be used as a surrogate in the absence of actual locality data when identifying target conservation areas and compiling management strategies for this very cryptic species. A by-product of this habitat analysis was the discovery of a long list of impacts on the long term survival of D. verrucosa. The combination of these stochastic and deterministic events will drive habitat change at rates beyond the species’ ability to adapt. Managing these variables forms the crux of its successful conservation. A conservation status revision, based on the formal IUCN criteria, indicate that D. verrucosa should be reclassified as Critically Endangered Category B2a and D.  

Dietary composition of endangered seahorses determined by stable isotope analysis

2017 ◽  
Vol 68 (5) ◽  
pp. 831 ◽  
Author(s):  
S. Valladares ◽  
D. X. Soto ◽  
M. Planas
Keyword(s):  
Stable Isotope ◽  
Environmental Changes ◽  
Conservation Status ◽  
Management Strategies ◽  
Isotope Analysis ◽  
Primary Source ◽  
Habitat Characteristics ◽  
Conservation Actions ◽  
Isotope Mixing Models ◽  
North Western

The lack of integrated measures for assessing the feeding ecology of seahorses may restrict the effectiveness of conservation actions on wild populations of worldwide threatened seahorse species. Identifying dietary sources will allow researchers to determine their degree of vulnerability to environmental changes, redefine their conservation status and apply appropriate management strategies. The resource use of the seahorse Hippocampus guttulatus inhabiting coastal waters of Galicia (north-western Iberian Peninsula) was assessed for three populations and 2 years using stable isotope mixing models. The Bayesian mixing model (MixSIAR) estimated the relative contributions of the dietary sources to the seahorse diet and revealed that Caprellidea were the primary source, followed by Gammaridea and Caridea. Mysidae and Annelida represented the less dominant prey. This prey preference can be explained by the foraging behaviour of seahorses. Different contributions of Gammaridea and Caridea to the diet were found among sites, indicating different habitat characteristics and hence different habitat use by seahorses within each site. In addition, differences were encountered among sexes. Caprellidea was the dominant prey for females, whereas Gammaridea was the dominant prey for males. The findings of the present study will contribute to the knowledge of feeding patterns of H. guttulatus, providing relevant data for conservation of this endangered species.

Physiological response and immediate mortality of gill-net-caught blacktip reef sharks (Carcharhinus melanopterus)

2017 ◽  
Vol 68 (9) ◽  
pp. 1734 ◽  
Author(s):  
Derek R. Dapp ◽  
Charlie Huveneers ◽  
Terence I. Walker ◽  
Richard D. Reina
Keyword(s):  
Conservation Status ◽  
Management Strategies ◽  
Population Monitoring ◽  
Mortality Rates ◽  
Plasma Lactate ◽  
Elevated Plasma ◽  
Gill Net ◽  
Reef Sharks ◽  
Carcharhinus Melanopterus ◽  
Related Mortality

To investigate factors contributing to immediate mortality in gill-net-caught elasmobranchs, we caught and blood sampled a total of 64 sharks and rays. Blacktip reef sharks (Carcharhinus melanopterus) were the most commonly caught species and had significantly elevated plasma lactate (mean 23.3 mM) and potassium (mean 6.2 mM) concentrations following capture, suggesting physiological disturbance. The overall immediate mortality rate of C. melanopterus was 38% and mortality was significantly influenced by body size, but not location of entanglement or sex. Of the other species caught, nervous sharks (Carcharhinus cautus) were of particular concern, because this species is often caught as bycatch by gill-net fisheries throughout its range and experienced high immediate mortality rates when captured (66%; n = 12) in the present study. The results suggest that juvenile C. melanopterus are particularly susceptible to gill-net-related mortality and that fisheries management strategies for C. melanopterus bycatch should focus on reducing the likelihood of juvenile sharks encountering this gear. Given that this species is not currently considered to be threatened with extinction, population monitoring should be performed such that the suggested regulations can be implemented if populations decline to levels threatening the conservation status of the species.

Habitat use by corn mice (Calomys musculinus) in cropfield borders of agricultural ecosystems in Argentina

2012 ◽  
Vol 39 (2) ◽  
pp. 112 ◽  
Author(s):  
Ivana Simone ◽  
Cecilia Provensal ◽  
Jaime Polop
Keyword(s):  
Habitat Use ◽  
Land Surface ◽  
Linear Models ◽  
Management Strategies ◽  
Habitat Characteristics ◽  
Tree Cover ◽  
Small Rodent ◽  
Individual Plant ◽  
Calomys Musculinus ◽  
Rodent Abundance

Context Calomys musculinus (Cricetidae, Sigmodontinae) is a small rodent species widely distributed in Argentina and particularly abundant in agroecosystems of the Pampean region, where it is known to select border habitats over cropfields. Aims The aim of the present research was to assess habitat use by C. musculinus in cropfield borders. Assuming that the number of rodent captures in each border reflects the intensity of use, we intended to identify the habitat characteristics that would account for abundance differences among borders. Methods Seasonal trapping sessions were carried out in borders of the rural zone of Chucul, Córdoba. Environmental variables were registered from both field surveys and remote-sensing imagery. Generalised linear models were used to identify the habitat variables associated with C. musculinus habitat use. Key results General fit of the models was fairly good; spring, summer and autumn models explained more than 55% of the variation in C. musculinus abundance among borders. Individual plant species were significant predictors of C. musculinus abundance, but they varied with seasons, whereas tree cover and border width were significant predictors in most seasons studied. In general, rodent abundance was positively associated with peanut and maize crops or maize stubbles and negatively related to soybean or its stubbles. In the coldest seasons, rodent abundance increased with increasing land-surface temperature of the border. Conclusions Border use by C. musculinus appeared to respond to differences in border quality, which seems to be more affected by those environmental characteristics that entail a reduction of the predatory risk rather than by those that involve food supply. Crop-fields may partially afford C. musculinus food requirements. Implications Because C. musculinus is the natural reservoir of a zoonotic agent, the identification of the habitat characteristics affecting rodent population numbers in borders may be of crucial importance for the implementation of ecologically based rodent-management strategies aimed at reducing human–rodent contacts. We suggest that wide borders, particularly those contiguous to maize and peanut cropfields, should be understood as priority sites for the implementation of specific control actions.

Serviços ecossistêmicos prestados por recifes de coral nas ilhas de Tinharé e Boipeba, Baixo Sul da Bahia, Brasil

2018 ◽  
Author(s):  
Carla Isobel Elliff
Keyword(s):  
Ecosystem Services ◽  
Coral Reefs ◽  
Current Model ◽  
Management Strategies ◽  
Environmental Indicators ◽  
Management Actions ◽  
Shoreline Protection ◽  
Fringing Reefs ◽  
Integrated Valuation ◽  
Reef Decline

Coral reefs provide important ecosystem services to coastal communities. The Archipelago of Tinhar?e andBoipeba, Bahia, Brazil, are mostly surrounded by fringing reefs, which have undergone several chronichuman impacts. The objective of the present study was to apply an ecosystem-based approach byanalyzing the ecosystem services provided by the coral reefs of the Archipelago of Tinhar?e and Boipeba inorder to support management actions and serve as a tool for coastal management. Ecosystem serviceswere assessed through the observation of environmental indicators of their occurrence and by using asuite of models from the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) softwarecombined with data from the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol database. Theservices of greatest occurrence were food provision, habitat maintenance, shoreline protection andrecreation. While the main stressful factors were tourism activities, the absence of a sewage system andfisheries. The coral reefs presented potential for shoreline protection along 50.5% of the islands. Moreover,46.8% of the shoreline would present moderate to high vulnerability in case of coral reef disappearance.The coincidence of areas with high risk of loss in the capacity to provide services and highvulnerability in the scenario of absence of reefs is concerning. Thus, the current model for tourism usedin the area should be altered, as should new management strategies be implemented, which can bringbenefits and avoid reef decline.

Temporal and Spatial Pattern of a Privet (Ligustrum vulgare) Invasion

2013 ◽  
Vol 6 (2) ◽  
pp. 310-319 ◽  
Author(s):  
Wanying Zhao ◽  
Charles Goebel ◽  
John Cardina
Keyword(s):  
Spatial Pattern ◽  
Spatial Data ◽  
Nearest Neighbor ◽  
Management Strategies ◽  
Age Distribution ◽  
Lag Phase ◽  
Suitable Habitat ◽  
Second Phase ◽  
Invasion History ◽  
Cumulative Number

AbstractPrivet has escaped from cultivation and is invading natural areas throughout eastern North America. Understanding the pattern of invasion over time could help us develop more efficient management strategies. We studied the invasion history and spatial distribution pattern of privet by mapping age and spatial data for established patches in a 132-ha (326 ac) forested natural area in northeast Ohio. We determined the age of 331 geo-referenced patches by counting annual rings, and mapped them with corresponding land habitat. Age distribution and cumulative number of privet patches over about 40 yr showed three phases of invasion. The initial 19-yr lag phase was characterized as a dispersed spatial pattern (based on nearest neighbor analysis), with patches located mostly at edges of different habitats and open places. In a second phase of about 15 yr, an average of 19 patches were initiated yearly, in a pattern that trended towards clustered. The final phase began around 2007, as the rate of new patch establishment declined, possibly because of saturation of the suitable habitat. Establishment of new patches was not associated with specific habitats. Aggregation of patches with similar ages increased after 1998 and became significantly clustered. Mapping of clusters of old and young patches identified invasion hot spots and barriers. Results affirmed that the best time for invasive control is during the lag phase. By monitoring edge habitats associated with early establishment, managers might detect and control early invaders and delay the onset of the expansion phase.

scholarly journals Predicting Impacts of Climate Change on Northward Range Expansion of Invasive Weeds in South Korea

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1604
Author(s):  
Sun Hee Hong ◽  
Yong Ho Lee ◽  
Gaeun Lee ◽  
Do-Hun Lee ◽  
Pradeep Adhikari
Keyword(s):  
Climate Change ◽  
South Korea ◽  
Habitat Suitability ◽  
Management Strategies ◽  
Southern Region ◽  
Suitable Habitat ◽  
Invasive Weeds ◽  
Northern Regions ◽  
Suitable Habitats ◽  
Control And Management

Predicting the distribution of invasive weeds under climate change is important for the early identification of areas that are susceptible to invasion and for the adoption of the best preventive measures. Here, we predicted the habitat suitability of 16 invasive weeds in response to climate change and land cover changes in South Korea using a maximum entropy modeling approach. Based on the predictions of the model, climate change is likely to increase habitat suitability. Currently, the area of moderately suitable and highly suitable habitats is estimated to be 8877.46 km2, and 990.29 km2, respectively, and these areas are expected to increase up to 496.52% by 2050 and 1439.65% by 2070 under the representative concentration pathways 4.5 scenario across the country. Although habitat suitability was estimated to be highest in the southern regions (<36° latitude), the central and northern regions are also predicted to have substantial increases in suitable habitat areas. Our study revealed that climate change would exacerbate the threat of northward weed invasions by shifting the climatic barriers of invasive weeds from the southern region. Thus, it is essential to initiate control and management strategies in the southern region to prevent further invasions into new areas.

scholarly journals Leopard Density Estimation within an Enclosed Reserve, Namibia Using Spatially Explicit Capture-Recapture Models

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 724
Author(s):  
Noack ◽  
Heyns ◽  
Rodenwoldt ◽  
Edwards
Keyword(s):  
Management Strategies ◽  
Camera Traps ◽  
Spatially Explicit ◽  
Conservation Areas ◽  
Term Survival ◽  
New Class ◽  
Capture Recapture ◽  
Wildlife Populations ◽  
Effective Conservation

The establishment of enclosed conservation areas are claimed to be the driving force for the long-term survival of wildlife populations. Whilst fencing provides an important tool in conservation, it simultaneously represents a controversial matter as it stops natural migration processes, which could ultimately lead to inbreeding, a decline in genetic diversity and local extinction if not managed correctly. Thus, wildlife residing in enclosed reserves requires effective conservation and management strategies, which are strongly reliant on robust population estimates. Here, we used camera traps combined with the relatively new class of spatially explicit capture-recaptured models (SECR) to produce the first reliable leopard population estimate for an enclosed reserve in Namibia. Leopard density was estimated at 14.51 leopards/100 km2, the highest recorded density in Namibia to date. A combination of high prey abundance, the absence of human persecution and a lack of top-down control are believed to be the main drivers of the recorded high leopard population. Our results add to the growing body of literature which suggests enclosed reserves have the potential to harbour high densities and highlight the importance of such reserves for the survival of threatened species in the future.

scholarly journals Habitat associations and conservation status of an endemic forest dwarf chameleon (Bradypodion sp.) from South Africa

Oryx ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Walter J. Reisinger ◽  
Devi M. Stuart-Fox ◽  
Barend F.N. Erasmus
Keyword(s):  
South Africa ◽  
Conservation Status ◽  
Canopy Cover ◽  
Iucn Red List ◽  
Habitat Associations ◽  
Suitable Habitat ◽  
Area Of Occupancy ◽  
Forest Interior ◽  
Forest Remnants ◽  
Iucn Red List Criteria

We quantified habitat associations and evaluated the conservation status of a recently identified, undescribed species of dwarf chameleon, Bradypodion sp. nov. Dhlinza, endemic to scarp forest remnants in KwaZulu-Natal Province, South Africa. At the microhabitat scale the Dhlinza dwarf chameleon was found more often in forest gaps and near paths than highly disturbed edges or forest interior. Chameleon presence was not explained by forest physiognomic variables such as vine cover, shrub and tree density, or canopy cover. Presence near gaps may be better explained by the combined effects of the thermal microenvironment and food availability. The species is moderately common where it occurs, with estimated densities of 4.7, 8.7 and 29.7 individuals per ha within forest interior, edges and gaps respectively. At the landscape scale, the chameleon occurs only in three remnant forests: the Dhlinza, Entumeni and Ongoye Forests. The species' extent of occurrence was estimated to be 88 km2 and its area of occupancy 49 km2. Based on the small area of remaining suitable habitat, this species meets the requirements for categorization as Endangered according to IUCN Red List criteria.

scholarly journals Habitat selection of Himalayan Musk Deer Moschus leucogaster (Mammalia: Artiodactyla: Moschidae) with respect to biophysical attributes in Annapurna Conservation Area of Nepal

2021 ◽  
Vol 13 (7) ◽  
pp. 18703-18712
Author(s):  
Bijaya Neupane ◽  
Nar Bahadur Chhetri ◽  
Bijaya Dhami
Keyword(s):  
Endangered Species ◽  
Management Strategies ◽  
Mixed Forest ◽  
Habitat Characteristics ◽  
Musk Deer ◽  
Importance Value Index ◽  
Importance Value ◽  
Conservation Area ◽  
Preferred Habitat ◽  
Annapurna Conservation Area

Himalayan or White-bellied Musk Deer Moschus leucogaster, an IUCN indexed endangered species, is distributed in isolated pockets in the Himalaya. The deer population is decreasing owing to several pressures that include habitat loss and fragmentation, and poaching. It is essential to identify preferred habitat characteristics to support appropriate management strategies for conserving this endangered species. This study was carried out in the Nysheang basin of Annapurna Conservation Area of Nepal to identify habitats preferred by the musk deer. Habitat field parameters were collected using transect surveys. To analyze vegetation use and availability, nested quadrate plots size 20 m2 were established. Ivlev’s electivity index (IV) (-1 to +1) was employed to determine habitat preference, and one-way ANOVA (F) and chi-square tests (χ2) were used to examine different habitat parameters. Similarly, the importance value index (IVI) of the vegetation was calculated. Our results showed that the Himalayan Musk Deer strongly preferred habitats at 3601–3800 m altitude (IV= 0.3, F= 4.58, P <0.05), with 21–30º slope (IV= 0.2, F= 4.14, P <0.05), 26–50 % crown cover (IV= 0.25, F= 4.45, P <0.05), 26–50 % ground cover (IV= 0.15, F= 4.13, P <0.05), and mixed forest (IV= 0.29, χ2= 28.82, df= 3, p <0.001). Among the trees, Abies spectabilis (IVI= 74.87, IV= 0.035) and Rhododendron arboretum (IVI= 55.41, IV= 0.02) were the most preferred, while Rhododendron lepidotum, Cassiope fastigiata (IV= 0.35) and Berberis aristata (IV= 0.25) were the most preferred shrubs, and Primula denticulata (IV= 0.87) and Primula rotundifolia (IV= 0.31) were the most preferred herbs. These preferred habitat conditions should be maintained and conserved to sustain a viable population of deer in the study area. Further studies will be required to assess the effects of climate change on habitat suitability. 

scholarly journals Increasing accuracy: The advantage of using open access species occurrence database in the Red List assessment

2020 ◽  
Vol 21 (8) ◽  
Author(s):  
Iyan Robiansyah ◽  
Wita Wardani
Keyword(s):  
Open Access ◽  
Extinction Risk ◽  
Conservation Status ◽  
Iucn Red List ◽  
Red List ◽  
Suitable Habitat ◽  
Herbarium Specimens ◽  
Species Occurrence ◽  
Extent Of Occurrence ◽  
Area Of Occupancy

Abstract. Robiansyah I, Wardani W. 2020. Increasing accuracy: The advantage of using open access species occurrence database in the Red List assessment. Biodiversitas 21: 3658-3664. IUCN Red List is the most widely used instrument to assess and advise the extinction risk of a species. One of the criteria used in IUCN Red List is geographical range of the species assessed (criterion B) in the form of extent of occurrence (EOO) and/or area of occupancy (AOO). While this criterion is presumed to be the easiest to be completed as it is based mainly on species occurrence data, there are some assessments that failed to maximize freely available databases. Here, we reassessed the conservation status of Cibotium arachnoideum, a tree fern distributed in Sumatra and Borneo. This species was previously assessed by Praptosuwiryo (2020, Biodiversitas 21 (4): 1379-1384) which classified the species as Endangered (EN) under criteria B2ab(i,ii,iii); C2a(ii). Using additional data from herbarium specimens recorded in the Global Biodiversity Information Facility (GBIF) website and from peer-reviewed scientific papers, in the present paper we show that C. arachnoideum has a larger extent of occurrence (EOO) and area of occupancy (AOO), more locations and different conservation status compared to those in Praptosuwiryo (2020). Our results are supported by the predicted suitable habitat map of C. arachnoideum produced by MaxEnt modelling method. Based on our assessment, we propose the category of Vulnerable (VU) C2a(i) as the global conservation status for C. arachnoideum. Our study implies the advantage of using open access databases to increase the accuracy of extinction risk assessment under the IUCN Red List criteria in regions like Indonesia, where adequate taxonomical information is not always readily available.

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