Bryophyte community structure in a boreal poor fen: reciprocal transplants

2001 ◽  
Vol 79 (4) ◽  
pp. 404-411 ◽  
Author(s):  
Roisín C Mulligan ◽  
L Dennis Gignac
Keyword(s):  
Community Structure ◽  
Dry Weight ◽  
Pleurozium Schreberi ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Poor Fen ◽  
Reciprocal Transplants ◽  
Sphagnum Fuscum ◽  
Species Tolerance ◽  
Present Distribution

The ability of four boreal bryophytes (Sphagnum angustifolium (C. Jens ex Russ.), Sphagnum fuscum (Schimp.) Klinggr., Sphagnum magellanicum Brid., and Pleurozium schreberi (Brid.) Mitt.) to live in each others' habitats was examined in a 1-year reciprocal transplant experiment conducted in a poor fen peatland in northern Alberta, Canada. Growth in length was determined by measuring increase in shoot length, and growth in dry weight was determined by subtracting final dry weight from initial predicted dry weight. Species tolerance ranges, which approximate to fundamental niches, were determined by the significant differences in growth among the species. Stepwise regression analyses indicated that depth to water was the most important factor for all species except S. fuscum. Pleurozium schreberi exhibited the narrowest potential distribution, indicating that its present distribution is likely the result of habitat limitation. Although S. magellanicum and S. angustifolium exhibited wide potential ecological amplitude, the distributions of these species are partially limited by habitat. Sphagnum fuscum was able to grow in all habitats, and its distribution is not limited by any of the habitat factors measured.Key words: peatland, moss, community structure, Sphagnum, Pleurozium schreberi, niche.

Ecological plasticity in Carex lyngbyei: evidence from transplant experiments

1989 ◽  
Vol 67 (12) ◽  
pp. 3618-3624 ◽  
Author(s):  
Susan R. Smythe ◽  
Ian Hutchinson
Keyword(s):  
Pacific Northwest ◽  
Shoot Density ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Shoot Height ◽  
Reciprocal Transplants ◽  
Morphological Differences ◽  
Northwestern North America ◽  
Transplant Site ◽  
Transplant Experiments

Four populations of Carex lyngbyei from each of three estuaries with contrasting salinity regimes in northwestern North America (deltas of the Nanaimo, Skagit, and Squamish rivers) were grown in a reciprocal transplant experiment to determine the degree to which morphological differences were genetic or environmentally based. Shoot height, biomass per shoot, and aboveground biomass differences were generally not maintained in the transplant environment, suggesting that genetic control on morphological variation was weak. Transplant site salinity regimes had little effect on shoot density or survival. It is suggested that broadly adapted genotypes, capable of this sort of plastic response, may have a competitive advantage in these fluctuating estuarine environments. Key words: Carex lyngbyei, Pacific Northwest, plasticity, reciprocal transplants.

Bryophyte community structure in a boreal poor fen II: interspecific competition among five mosses

2002 ◽  
Vol 80 (4) ◽  
pp. 330-339 ◽  
Author(s):  
Roisín C Mulligan ◽  
L Dennis Gignac
Keyword(s):  
Competitive Ability ◽  
Transplant Experiment ◽  
Competitive Effect ◽  
Relative Growth ◽  
Poor Fen ◽  
Feather Mosses ◽  
Sphagnum Fuscum ◽  
Northern Alberta ◽  
Sphagnum Magellanicum ◽  
Study Species

A possible competitive hierarchy among five boreal bryophytes (Sphagnum angustifolium, Sphagnum fuscum, Sphagnum magellanicum, Ptilium crista-castrensis, and Pleurozium schreberi) was examined in a 2-year transplant experiment conducted in two habitats of a poor fen in northern Alberta, Canada, using a sixth moss (Aulacomnium palustre) as a phytometer. Change in relative growth rate in length and weight of A. palustre, measured as competitive effect, indicated the existence of a hierarchy in this peatland wherein the feather mosses are subordinates to the Sphagnum mosses. Relative competitive performance, which was calculated relative to the growth of the phytometer in monoculture, indicated that S. magellanicum exhibited the greatest competitive effect. Sphagnum magellanicum may be a strong competitor and partially inhibit S. fuscum from occupying its full fundamental niche. The competitive ability of S. fuscum and S. angustifolium in this peatland is low relative to that of the other study species. The feather mosses did not demonstrate competitive effect and may have facilitated growth of the phytometer.Key words: bryophyte, competition, feather moss, peatland, phytometer, Sphagnum.

scholarly journals Environmental exposure does not explain putative maladaptation in road-adjacent populations

2016 ◽  
Author(s):  
Steven P. Brady
Keyword(s):  
Natural Selection ◽  
Early Stage ◽  
Local Environment ◽  
Later Life ◽  
Pond Water ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Embryonic Exposure ◽  
Reciprocal Transplants ◽  
Show Evidence

AbstractWhile the ecological consequences of roads are well described, little is known of their role as agents of natural selection, which can shape adaptive and maladaptive responses in populations influenced by roads. This is despite a growing appreciation for the influence of evolution in human-altered environments. There, insights indicate that natural selection typically results in local adaptation. Thus populations influenced by road-induced selection should evolve fitness advantages in their local environment. Contrary to this expectation, wood frog tadpoles from roadside populations show evidence of a fitness disadvantage, consistent with local maladaptation. Specifically, in reciprocal transplants, roadside populations survive at lower rates compared to populations away from roads. A key question remaining is whether roadside environmental conditions experienced by early-stage embryos induce this outcome. This represents an important missing piece in evaluating the evolutionary nature of this maladaptation pattern. Here, I address this gap using a reciprocal transplant experiment designed to test the hypothesis that embryonic exposure to roadside pond water induces a survival disadvantage. Contrary to this hypothesis, my results show that reduced survival persists when embryonic exposure is controlled. This indicates that the survival disadvantage is parentally mediated, either genetically and/or through inherited environmental effects. This result suggests that roadside populations are either truly maladapted or potentially locally adapted at later life stages. I discuss these interpretations, noting that regardless of mechanism, patterns consistent with maladaptation have important implications for conservation. In light of the pervasiveness of roads, further resolution explaining maladaptive responses remains a critical challenge in conservation.

Bryophyte community structure in a boreal poor fen: reciprocal transplants

2001 ◽  
Vol 79 (4) ◽  
pp. 404-411 ◽  
Author(s):  
Roisín C. Mulligan ◽  
L. Dennis Gignac
Keyword(s):  
Community Structure ◽  
Poor Fen ◽  
Reciprocal Transplants

scholarly journals Does Local Adaptation Impact on the Distribution of Competing Aedes Disease Vectors?

Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Kelly L. Bennett ◽  
William Owen McMillan ◽  
Jose R. Loaiza
Keyword(s):  
Local Adaptation ◽  
Resource Competition ◽  
Disease Vectors ◽  
Human Populations ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Climate Conditions ◽  
Ecological Resources ◽  
The Face ◽  
Arboviral Disease

Ae. (Stegomyia) aegypti L. and Aedes (Stegomyia) albopictus Skuse mosquitoes are major arboviral disease vectors in human populations. Interspecific competition between these species shapes their distribution and hence the incidence of disease. While Ae. albopictus is considered a superior competitor for ecological resources and displaces its contender Ae. aegypti from most environments, the latter is able to persist with Ae. albopictus under particular environmental conditions, suggesting species occurrence cannot be explained by resource competition alone. The environment is an important determinant of species displacement or coexistence, although the factors underpinning its role remain little understood. In addition, it has been found that Ae. aegypti can be adapted to the environment across a local scale. Based on data from the Neotropical country of Panama, we present the hypothesis that local adaptation to the environment is critical in determining the persistence of Ae. aegypti in the face of its direct competitor Ae. albopictus. We show that although Ae. albopictus has displaced Ae. aegypti in some areas of Panama, both species coexist across many areas, including regions where Ae. aegypti appear to be locally adapted to dry climate conditions and less vegetated environments. Based on these findings, we describe a reciprocal transplant experiment to test our hypothesis, with findings expected to provide fundamental insights into the role of environmental variation in shaping the landscape of emerging arboviral disease.

scholarly journals Effect of Soil Ammonium Concentration on N2O Release and on the Community Structure of Ammonia Oxidizers and Denitrifiers

2002 ◽  
Vol 68 (11) ◽  
pp. 5685-5692 ◽  
Author(s):  
Sharon Avrahami ◽  
Ralf Conrad ◽  
Gesche Braker
Keyword(s):  
Phylogenetic Analysis ◽  
Community Structure ◽  
Soil Microbial Communities ◽  
Rflp Analysis ◽  
Dry Weight ◽  
Small Subunit ◽  
Ammonium Concentration ◽  
Ammonia Oxidizers ◽  
Community Shift ◽  
Gradient Gel Electrophoresis

ABSTRACT The effect of ammonium addition (6.5, 58, and 395 μg of NH4 +-N g [dry weight] of soil−1) on soil microbial communities was explored. For medium and high ammonium concentrations, increased N2O release rates and a shift toward a higher contribution of nitrification to N2O release occurred after incubation for 5 days at 4°C. Communities of ammonia oxidizers were assayed after 4 weeks of incubation by denaturant gradient gel electrophoresis (DGGE) of the amoA gene coding for the small subunit of ammonia monooxygenase. The DGGE fingerprints were invariably the same whether the soil was untreated or incubated with low, medium, or high ammonium concentrations. Phylogenetic analysis of cloned PCR products from excised DGGE bands detected amoA sequences which probably belonged to Nitrosospira 16S rRNA clusters 3 and 4. Additional clones clustered with Nitrosospira sp. strains Ka3 and Ka4 and within an amoA cluster from unknown species. A Nitrosomonas-like amoA gene was detected in only one clone. In agreement with the amoA results, community profiles of total bacteria analyzed by terminal restriction fragment length polymorphism (T-RFLP) showed only minor differences. However, a community shift occurred for denitrifier populations based on T-RFLP analysis of nirK genes encoding copper-containing nitrite reductase with incubation at medium and high ammonia concentrations. Major terminal restriction fragments observed in environmental samples were further described by correspondence to cloned nirK genes from the same soil. Phylogenetic analysis grouped these clones into clusters of soil nirK genes. However, some clones were also closely related to genes from known denitrifiers. The shift in the denitrifier community was probably the consequence of the increased supply of oxidized nitrogen through nitrification. Nitrification activity increased upon addition of ammonium, but the community structure of ammonium oxidizers did not change.

Maternal effects and drought tolerance determine seedling establishment success in a common roadside plant, Dipsacus fullonum subsp sylvestris

Botany ◽  
2010 ◽  
Vol 88 (10) ◽  
pp. 930-936 ◽  
Author(s):  
Laura L. Beaton ◽  
Susan A. Dudley
Keyword(s):  
Drought Tolerance ◽  
Seedling Establishment ◽  
Seed Mass ◽  
Growth Stages ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Maternal Provisioning ◽  
Average Size ◽  
Roadside Environment

Previous studies have demonstrated that plants collected as seeds from roadside populations of Dipsacus fullonum L. subsp sylvestris (Huds.) Claphamare more tolerant of high salinity, low osmotic potentials, and hypoxia during juvenile growth stages than those from oldfield populations. However, it is unclear how tolerance to these abiotic stressors translates into performance in the roadside environment. Here, we conducted a reciprocal transplant experiment between oldfield and roadside environments. Seeds from three roadside and three oldfield populations were planted into oldfield and roadside sites in late fall. Throughout the spring and summer, the survivorship and size of the seedlings were monitored to examine differences in performance in the two habitats. We also assessed the relation between performance in the field and previous in vitro measures of salt and drought tolerance of each population. A drought caused high mortality levels in the oldfield and roadside. Individuals from roadside populations did not exhibit increased growth or survivorship in the roadside environment. In the early months of seedling growth, neither salt nor drought tolerance were significantly correlated with performance in the roadside during seedling establishment. Rather, during these early months, the average size of individuals in each population in the field was positively correlated with the population’s average seed mass, indicating that maternal provisioning had a greater impact than tolerance to particular environmental stresses during the juvenile stages of development. However, later in the summer, after the drought began, the average size of individuals from each population in the field was positively correlated with that population’s average drought tolerance.

Performance of four mosses in a reciprocal transplant experiment: implications for peatland succession in NE China

2013 ◽  
Vol 35 (3) ◽  
pp. 220-227 ◽  
Author(s):  
Zhaojun Bu ◽  
Xu Chen ◽  
Håkan Rydin ◽  
Shengzhong Wang ◽  
Jinze Ma ◽  
...  
Keyword(s):  
Reciprocal Transplant ◽  
Transplant Experiment ◽  
Ne China ◽  
Reciprocal Transplant Experiment
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