scholarly journals Rodent sociality and parasite diversity

2007 ◽  
Vol 3 (6) ◽  
pp. 692-694 ◽  
Author(s):  
Frédéric Bordes ◽  
Daniel T Blumstein ◽  
Serge Morand
Keyword(s):  
Species Richness ◽  
Group Size ◽  
Host Species ◽  
Independent Contrasts ◽  
Parasite Diversity ◽  
Social Species ◽  
Dilution Effects ◽  
The Relationship ◽  
Biotic Environment

The risk of parasitism is considered to be a general cost of sociality and individuals living in larger groups are typically considered to be more likely to be infected with parasites. However, contradictory results have been reported for the relationship between group size and infection by directly transmitted parasites. We used independent contrasts to examine the relationship between an index of sociality in rodents and the diversity of their macroparasites (helminths and arthropods such as fleas, ticks, suckling lice and mesostigmatid mites). We found that the species richness of directly transmitted ectoparasites, but not endoparasites, decreased significantly with the level of rodent sociality. A greater homogeneity in the biotic environment (i.e. a reduced number of cohabiting host species) of the more social species may have reduced ectoparasites' diversity by impairing ectoparasites transmission and exchange. Our finding may also result from beneficial outcomes of social living that include behavioural defences, like allogrooming, and the increased avoidance of parasites through dilution effects.

scholarly journals Poor geographical match between the distributions of host diversity and parasite discovery effort

2018 ◽  
Vol 285 (1879) ◽  
pp. 20180072 ◽  
Author(s):  
Fátima Jorge ◽  
Robert Poulin
Keyword(s):  
Species Richness ◽  
Geographical Distribution ◽  
Host Species ◽  
Parasite Species ◽  
Research Effort ◽  
Helminth Parasites ◽  
Parasite Diversity ◽  
Species Discovery ◽  
Host Diversity ◽  
Parasite Biodiversity

Mapping global parasite diversity is crucial to identify geographical hotspots of emerging disease, and guide public health and conservation efforts. In principle, assuming a bottom-up coupling between the diversity of resources and consumers, the geographical distribution of parasite diversity should match that of host diversity. We test the expected spatial congruence between host and parasite diversity for helminth parasites of vertebrate hosts, across grid cells of a global map. Using high-resolution databases on host species distributions and newly compiled data on the geographical distribution of parasite species discovery, we found positive covariation between host species richness and the number of parasite species discovered, for all vertebrate groups, regardless of the analytical method used, spatial autocorrelation, and spatial resolution. However, all associations were very weak, indicating a poor match between host species richness and parasite species discovery. The research deficit in parasite discovery peaks in areas corresponding to hotspots of host diversity, where disproportionately fewer new parasites are discovered than expected based on local host richness. This spatially biased research effort prevents a full inventory of parasite biodiversity, and impedes predictions of where new diseases may emerge. The host taxon-specific maps we produced, however, can guide future efforts to uncover parasite biodiversity.

scholarly journals Biodiversity loss decreases parasite diversity: theory and patterns

2012 ◽  
Vol 367 (1604) ◽  
pp. 2814-2827 ◽  
Author(s):  
Kevin D. Lafferty
Keyword(s):  
Species Richness ◽  
Food Web ◽  
Biodiversity Loss ◽  
Parasite Diversity ◽  
Free Living ◽  
Parasite Richness ◽  
Living Species ◽  
Host Parasite ◽  
Food Web Complexity ◽  
The Relationship

Past models have suggested host–parasite coextinction could lead to linear, or concave down relationships between free-living species richness and parasite richness. I explored several models for the relationship between parasite richness and biodiversity loss. Life cycle complexity, low generality of parasites and sensitivity of hosts reduced the robustness of parasite species to the loss of free-living species diversity. Food-web complexity and the ordering of extinctions altered these relationships in unpredictable ways. Each disassembly of a food web resulted in a unique relationship between parasite richness and the richness of free-living species, because the extinction trajectory of parasites was sensitive to the order of extinctions of free-living species. However, the average of many disassemblies tended to approximate an analytical model. Parasites of specialist hosts and hosts higher on food chains were more likely to go extinct in food-web models. Furthermore, correlated extinctions between hosts and parasites (e.g. if parasites share a host with a specialist predator) led to steeper declines in parasite richness with biodiversity loss. In empirical food webs with random removals of free-living species, the relationship between free-living species richness and parasite richness was, on average, quasi-linear, suggesting biodiversity loss reduces parasite diversity more than previously thought.

scholarly journals Relationships between resource availability and elevation vary between metrics creating gradients of nutritional complexity

Oecologia ◽  
2021 ◽  
Vol 195 (1) ◽  
pp. 213-223
Author(s):  
Mark A. Lee ◽  
Grace Burger ◽  
Emma R. Green ◽  
Pepijn W. Kooij
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Resource Availability ◽  
Plant Biomass ◽  
Plant Species Richness ◽  
Mineral Contents ◽  
Nutritive Values ◽  
Animal Community ◽  
Nutritional Chemistry ◽  
The Relationship

AbstractPlant and animal community composition changes at higher elevations on mountains. Plant and animal species richness generally declines with elevation, but the shape of the relationship differs between taxa. There are several proposed mechanisms, including the productivity hypotheses; that declines in available plant biomass confers fewer resources to consumers, thus supporting fewer species. We investigated resource availability as we ascended three aspects of Helvellyn mountain, UK, measuring several plant nutritive metrics, plant species richness and biomass. We observed a linear decline in plant species richness as we ascended the mountain but there was a unimodal relationship between plant biomass and elevation. Generally, the highest biomass values at mid-elevations were associated with the lowest nutritive values, except mineral contents which declined with elevation. Intra-specific and inter-specific increases in nutritive values nearer the top and bottom of the mountain indicated that physiological, phenological and compositional mechanisms may have played a role. The shape of the relationship between resource availability and elevation was different depending on the metric. Many consumers actively select or avoid plants based on their nutritive values and the abundances of consumer taxa vary in their relationships with elevation. Consideration of multiple nutritive metrics and of the nutritional requirements of the consumer may provide a greater understanding of changes to plant and animal communities at higher elevations. We propose a novel hypothesis for explaining elevational diversity gradients, which warrants further study; the ‘nutritional complexity hypothesis’, where consumer species coexist due to greater variation in the nutritional chemistry of plants.

scholarly journals Roles of Spatial Scale and Rarity on the Relationship between Butterfly Species Richness and Human Density in South Africa

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124327 ◽  
Author(s):  
Silvia Mecenero ◽  
Res Altwegg ◽  
Jonathan F. Colville ◽  
Colin M. Beale
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Spatial Scale ◽  
Butterfly Species ◽  
The Relationship ◽  
Human Density

The relationship between forelimb morphology and behaviour in North American carnivores (Carnivora)

1999 ◽  
Vol 77 (7) ◽  
pp. 1064-1074 ◽  
Author(s):  
Andrew N Iwaniuk ◽  
Sergio M Pellis ◽  
Ian Q Whishaw
Keyword(s):  
North American ◽  
Significant Relationship ◽  
Feeding Behaviour ◽  
Prey Capture ◽  
Relative Size ◽  
Independent Contrasts ◽  
Important Indicator ◽  
Predatory Behaviour ◽  
Olecranon Process ◽  
The Relationship

We tested the validity of previously described relationships between forelimb structure and behaviour in mammals by measuring the forelimbs of 22 species of North American carnivores. Nine ratios were calculated from these measurements and made independent of the effects of allometry and phylogeny through the use of log-transformed regressions and independent contrasts analysis. The ratios were then directly compared with two behavioural traits: arboreal locomotion and vertebrate predation. Only five of the nine ratios exhibited a significant relationship with arboreal locomotion and three with vertebrate predation. It was concluded that the brachial index, relative size of the olecranon process, and total forelimb robusticity may be reliable predictors of arboreal locomotion, and that the brachial index, relative size of the olecranon process, and radial robusticity may be accurate predictors of vertebrate predation. The data also suggest that the morphology of the lower forelimb may be an important indicator of prey-capture and feeding behaviour in carnivores and could be used in conjunction with craniodental variables to extrapolate predatory behaviour of extinct species.

scholarly journals Do syntopic host species harbour similar symbiotic communities? The case ofChaetopterusspp. (Annelida: Chaetopteridae)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2930 ◽  
Author(s):  
Temir A. Britayev ◽  
Elena Mekhova ◽  
Yury Deart ◽  
Daniel Martin
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Host Species ◽  
Interspecific Interactions ◽  
Single Species ◽  
Intraspecific Interactions ◽  
Mean Intensity ◽  
Species Dominance ◽  
High Species Richness ◽  
Symbiotic Community

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes,Chaetopterussp. (n = 11) andChaetopteruscf.appendiculatus(n = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabsPolyonyxcf.heokandPolyonyxsp., the pinnotherid crabTetriassp. and the tergipedid nudibranchPhestillasp. The latter harboured the polynoid polychaeteOphthalmonoe pettiboneae, the carapid fishOnuxodon fowleriand the porcellanid crabEulenaios cometes, all of which, exceptO. fowleri, seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher inChaetopterussp. than inC.cf.appendiculatus(1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively). We suggest that the lower density ofChaetopterussp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% inC.cf.appenciculatus). MostChaetopterussp. harboured two symbiotic species, which was extremely rare inC.cf.appendiculatus, suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts ofChaetopterussp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes ofChaetopterussp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated withC.cf.appendiculatusestablished a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the differences in community structure observed. We hypothesize that both host species could originally be allopatric. The evolutionary specialization of the symbiotic communities would occur in separated geographical areas, while the posterior disappearance of the existing geographical barriers would lead to the overlapped distribution.

scholarly journals The influence of forest-forming tree species on diversity and spatial distribution of algae in forest litter

2018 ◽  
Vol 45 (2) ◽  
pp. 72-81 ◽  
Author(s):  
Yevhen Maltsev ◽  
Irina Maltseva
Keyword(s):  
Species Richness ◽  
Leaf Litter ◽  
Green Algae ◽  
Tree Species ◽  
Spatial Organization ◽  
Forest Litter ◽  
Equal Distribution ◽  
Blue Green Algae ◽  
Different Types ◽  
The Relationship

Abstract The forest litter plays a significant role in forest ecosystems. The composition of the litter biota comprises micro- and mesofauna, and a great diversity of microorganisms, including unrecognized algae (eukaryotic representatives and Cyanoprokaryota). The aim of this work was to study the diversity of algae in the different types of forest litters and to clarify the relationship between the algae composition and the forest-forming tree species. Our results show that the pine forest litter is the most appropriate habitat for the development of green and yellow-green algae and that this litter type limits the variety of blue-green ones. The admixture of deciduous leaf litter to pine litter caused an increase in the species richness of blue-green algae and diatoms. The algae were unevenly distributed across the sub-horizons of pine litter. The highest species richness of algae was identified in the enzymatic sub-horizon of litter. The peculiarity of the composition of leaf litter algae was a significant variety of green, yellow-green and blue-green algae. The spatial organization of algae communities in the leaf litter was characterized by equal distribution of algae species in the litter-subhorizons.

The effects of glyphosate and triclopyr on common bryophytes and lichens in northwestern Ontario

1999 ◽  
Vol 29 (7) ◽  
pp. 1101-1111 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell ◽  
Dale H Vitt
Keyword(s):  
Species Richness ◽  
Community Dynamics ◽  
Herbicide Application ◽  
Northwestern Ontario ◽  
Application Rates ◽  
Open Forest ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
The Relationship

The effects of two silvicultural herbicides (Vision®, Release®) on bryophytes and lichens were studied in a harvested boreal mixedwood ecosystem. A completely randomized design with 115 plots of 1 m2 allowed direct comparison between herbicides and their effects on community dynamics. Regression models were used to analyze the relationship between herbicide application rates (0.71-6.72 kg active ingredient/ha) and changes in bryophyte and lichen abundance and species richness for 2 years following herbicide application. Results showed that bryophyte and lichen abundance and species richness decreased after herbicide treatments. In general, herbicide applications reduced the diversity of forest mesophytes and weedy colonizers to an ecosystem with only a few species of colonizers. A combination of clustering techniques and ANOVA were used to divide bryophytes and lichens into three ecologically defined response groups: herbicide-tolerant colonizers, semi tolerant long-term stayers from dry open forest, and sensitive forest mesophytes.

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