scholarly journals On the rediscovery of a rare root parasite Gleadovia ruborum Gamble & Prain (Orobanchaceae) from Uttarakhand, western Himalaya, India

2021 ◽  
Vol 13 (8) ◽  
pp. 19185-19188
Author(s):  
Amit Kumar ◽  
Navendu Page ◽  
Bhupendra S. Adhikari ◽  
Manoj V. Nair ◽  
Gopal S. Rawat
Keyword(s):  
Host Species ◽  
Western Himalaya ◽  
Habitat Characteristics ◽  
Moist Forest ◽  
Root Parasite ◽  
Abies Pindrow ◽  
The Individual ◽  
Quercus Floribunda

Gleadovia ruborum Gamble & Prain (Orobanchaceae), a rare root parasite is recorded after a gap of 57 years from a new locality in Uttarakhand, western Himalaya.  A total of four individuals were located in a shady moist forest of Abies pindrow-Quercus floribunda at Surkanda hill near Mussoorie.  All the individual plants were growing on the roots of Rubus pedunculosus D. Don.  The current communication provides an updated description, habitat characteristics and host species of Gleadovia ruborum.

scholarly journals Community disassembly and disease: realistic—but not randomized—biodiversity losses enhance parasite transmission

2019 ◽  
Vol 286 (1902) ◽  
pp. 20190260 ◽  
Author(s):  
Pieter T. J. Johnson ◽  
Dana M. Calhoun ◽  
Tawni Riepe ◽  
Travis McDevitt-Galles ◽  
Janet Koprivnikar
Keyword(s):  
Species Composition ◽  
Host Species ◽  
Host Community ◽  
Trematode Species ◽  
Parasite Transmission ◽  
Field Surveys ◽  
Larval Amphibians ◽  
Experimental Approaches ◽  
The Individual ◽  
The Relationship

Debates over the relationship between biodiversity and disease dynamics underscore the need for a more mechanistic understanding of how changes in host community composition influence parasite transmission. Focusing on interactions between larval amphibians and trematode parasites, we experimentally contrasted the effects of host richness and species composition to identify the individual and joint contributions of both parameters on the infection levels of three trematode species. By combining experimental approaches with field surveys from 147 ponds, we further evaluated how richness effects differed between randomized and realistic patterns of species loss (i.e. community disassembly). Our results indicated that community-level changes in infection levels were owing to host species composition, rather than richness. However, when composition patterns mirrored empirical observations along a natural assembly gradient, each added host species reduced infection success by 12–55%. No such effects occurred when assemblages were randomized. Mechanistically, these patterns were due to non-random host species assembly/disassembly: while highly competent species predominated in low diversity systems, less susceptible hosts became progressively more common as richness increased. These findings highlight the potential for combining information on host traits and assembly patterns to forecast diversity-mediated changes in multi-host disease systems.

scholarly journals Modelling the ecological niche from functional traits

2010 ◽  
Vol 365 (1557) ◽  
pp. 3469-3483 ◽  
Author(s):  
Michael Kearney ◽  
Stephen J. Simpson ◽  
David Raubenheimer ◽  
Brian Helmuth
Keyword(s):  
Functional Traits ◽  
Evolutionary Biology ◽  
Functional Trait ◽  
Habitat Characteristics ◽  
Great Promise ◽  
Vital Rates ◽  
Theoretical Frameworks ◽  
Geometric Framework ◽  
Population Growth Rates ◽  
The Individual

The niche concept is central to ecology but is often depicted descriptively through observing associations between organisms and habitats. Here, we argue for the importance of mechanistically modelling niches based on functional traits of organisms and explore the possibilities for achieving this through the integration of three theoretical frameworks: biophysical ecology (BE), the geometric framework for nutrition (GF) and dynamic energy budget (DEB) models. These three frameworks are fundamentally based on the conservation laws of thermodynamics, describing energy and mass balance at the level of the individual and capturing the prodigious predictive power of the concepts of ‘homeostasis’ and ‘evolutionary fitness’. BE and the GF provide mechanistic multi-dimensional depictions of climatic and nutritional niches, respectively, providing a foundation for linking organismal traits (morphology, physiology, behaviour) with habitat characteristics. In turn, they provide driving inputs and cost functions for mass/energy allocation within the individual as determined by DEB models. We show how integration of the three frameworks permits calculation of activity constraints, vital rates (survival, development, growth, reproduction) and ultimately population growth rates and species distributions. When integrated with contemporary niche theory, functional trait niche models hold great promise for tackling major questions in ecology and evolutionary biology.

Issues Based on Species Life History and Behavior

2021 ◽  
pp. 89-94
Author(s):  
Joseph A. Veech
Keyword(s):  
Life History ◽  
Habitat Use ◽  
Life Histories ◽  
Radio Telemetry ◽  
Spatial Scales ◽  
Habitat Associations ◽  
Habitat Characteristics ◽  
Habitat Analysis ◽  
The Individual ◽  
And Behavior

Species vary tremendously in their life histories and behavior. The particular life history traits and behavior of the focal species must be considered when designing a study to examine habitat associations. For some species, individuals use different areas (of the landscape or territory) for breeding and foraging. As such, the important characteristics for the foraging and breeding habitats may be different. The dramatically different life stages of some organisms (e.g., amphibians and some insects) often correspond to equally dramatic differences in habitat use between juveniles and adults. For some species, habitat use differs among seasons. Species that are highly mobile and have individuals that move around substantially on a daily or weekly basis are particularly challenging for a habitat analysis. For these species, the most efficient and appropriate study design may be one that tracks individuals (through radio-telemetry or GPS) and analyzes the environmental or habitat characteristics at locations where the individual has stopped, rather than trying to survey for the species in pre-established and insufficiently small survey plots. In addition, individual movement and the issues mentioned above may necessitate that environmental variables are measured and analyzed at multiple spatial scales.

scholarly journals Distribution of seasonal snow cover in central and western Himalaya

2010 ◽  
Vol 51 (54) ◽  
pp. 123-128 ◽  
Author(s):  
Anil V. Kulkarni ◽  
B.P. Rathore ◽  
S.K. Singh ◽  
Ajai
Keyword(s):  
Snow Cover ◽  
Western Himalaya ◽  
Snow Accumulation ◽  
Wide Field ◽  
Seasonal Snow ◽  
Snow Line ◽  
Field Sensor ◽  
Normalized Difference Snow Index ◽  
The Individual ◽  
Seasonal Snow Cover

AbstractIndian rivers originating in the Himalaya depend on seasonal snow-cover melt during crucial summer months. The seasonal snow cover was monitored using Advanced Wide Field Sensor (AWiFS) data of the Indian Remote Sensing Satellite (IRS) and using the Normalized Difference Snow Index (NDSI) algorithm. The investigation was carried out for a period of 3 years (2004/05, 2005/06 and 2006/07) between October and June. A total of 28 sub-basins of the Ganga and Indus river basins were monitored at intervals of 5 or 10 days. Approximately 1500 AWiFS scenes were analyzed. A combination of area–altitude distribution and snow map was used to estimate the distribution of snow cover in altitude zones for the individual basins and for the western and central Himalaya. Hypsographic curve and snow-free area was used to estimate monthly snow-line elevation. The lowest snow-line altitude in the winters of 2004/05, 2005/06 and 2006/07 was observed at 2480 ma.s.l. on 25 February 2005. In Ravi basin for the year 2004/05, snow accumulation and ablation were continuous processes throughout the winter. Even in the middle of winter, the snow area was reduced from 90% to 55%. Similar trends were observed for 2005/06 and 2007/08. In Bhaga basin, snowmelt was observed in the early part of the winter, i.e. in December, and no significant melting was observed between January and April.

Nodulation of Casuarinaceae in Relation to Host Species and Soil Properties

1986 ◽  
Vol 34 (4) ◽  
pp. 435 ◽  
Author(s):  
P Reddell ◽  
GD Bowen ◽  
AD Robson
Keyword(s):  
Host Species ◽  
Field Survey ◽  
Chemical Properties ◽  
Arbuscular Mycorrhizas ◽  
Soil Chemical Properties ◽  
Individual Species ◽  
Available Phosphorus ◽  
Field Soils ◽  
Low Phosphorus ◽  
The Individual

A field survey was conducted in Australia to examine nodulation of Casuarinaceae in relation to 22 host species (187 sites) and soil chemical properties (152 sites). Four of the five Casuarina species examined were regularly nodulated (most plants in the 60 out of 88 sites in which nodules were found). Casuarina species occurred more frequently on soils of higher available-phosphorus status than did Allocasuarina species, eight of which did not nodulate in any soils. With the nine Allocasuarina species which nodulated,nodules occurred on only a minority of the individual plants examined. Soil chemical properties other than available-phosphorus level were useful in distinguishing sites at which individual species occurred but had no apparent relationship to nodulation. Under glasshouse conditions, baiting of field soils with seedlings of Casuarinaceae indicated the occurrence of nodulation to be similar to that observed in the field survey. Allocasuarina species formed ectomycorrhizas more commonly than did Casuarina species; both genera formed vesicular-arbuscular mycorrhizas. A second glasshouse experiment supported the hypothesis that low phosphorus supply and the absence of infective Frankia were two of the factors responsible for the absence of nodulation in some field soils. The effects of other soil factors in limiting plant growth and nodulation of Casuarinaceae are considered, and the potential significance of N2 fixation by Casuarinaceae in the field discussed. Nodules were found on Allocasuarina campestris, A. dielsrana and A. lehmanniana, not previously recorded as nodulating.

scholarly journals Environmental conditions that promote the occurrence of truffles (Tuber spp.) on historical sites in Poland

2014 ◽  
Vol 75 (1) ◽  
pp. 5-11
Author(s):  
Aleksandra Rosa-Gruszecka ◽  
Dorota Hilszczańska ◽  
Hanna Szmidla
Keyword(s):  
Host Species ◽  
Calcium Content ◽  
Habitat Characteristics ◽  
Soil Parameters ◽  
Tuber Aestivum ◽  
Key Factors ◽  
Environmental Requirements ◽  
Historical Sites ◽  
Natural Stands ◽  
Epipactis Helleborine

Abstract This article highlights historical data regarding truffles’ occurrence in Poland. Along with the soil parameters the plant communities at the sites were studied. The results of the chemical soil analyses showed that the soil pH in water on 5 sites was acidic (from 4.3 to 6.1), and only in one, Wiązowna, was the pH (7.2) conductive to truffles development. Similarly, the content of calcium carbonate (CaCO3) in soil samples was low (from 0 to 0.03%), except for Wiązowna, where CaCO3 was 0.12%. Among the 24 reported species of trees and shrubs, 7 species were host-plants of summer truffle (Tuber aestivum Vitt.). Out of the 7 species, oak and hornbeam were present at four localisations. Across the sites, 31 species of ground-layer plants were identified. Among these, Epipactis helleborine was only one host-species of summer truffle. Our findings indicate that formation of truffles fruiting-bodies depends on specific habitat characteristics. The key factors determining this process are soil parameters, such as: texture, pH and calcium content. Our inventory showed that the sites we studied still persist as natural stands, although only one of them seems to be favorable for truffles development: this site is located in Wiązowna, where soil is of pH 7.2 and E. helleborine, (host species for truffles from Orchidaceae) is found, fulfills the environmental requirements of truffles

Egg size and form as taxonomic criteria in Diphyllobothrium (Cestoda, Pseudophyllidea)

Parasitology ◽  
1978 ◽  
Vol 76 (2) ◽  
pp. 229-240 ◽  
Author(s):  
Karin Andersen ◽  
Odd Halvorsen
Keyword(s):  
Host Species ◽  
Egg Production ◽  
Egg Size ◽  
Population Level ◽  
Width Ratio ◽  
Individual Level ◽  
Length Width ◽  
The Mean ◽  
The Individual ◽  
Single Worm

SummaryThe size and form (length, width, and length: width ratio) of eggs of Diphyllobothrium dendriticum, D. ditremum and D. laturn vary considerably among individual worms within each species. The size of eggs varies with host species and a decrease in egg size with increasing intensity of infestation is indicated. The egg size of D. laturn increases during the first 10–12 days of egg production. For single worm infections in golden hamsters the mean egg length and width of D. ditremum are significantly smaller than the corresponding means of D. dendriticum and D. latum, while D. latum has significantly wider eggs than D. dendriticum. As taxonomic characteristics, egg size and form may contribute to species delimitation at the population level. For identification at the individual level the best possible accuracy is about 80%. This accuracy is considerably reduced when variation in host species and intensities of infestations are introduced. Scanning electron microscope studies did not reveal any differences among eggs of the three species.

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