Evolutionary priority effects in New Zealand alpine plants across environmental gradients

Two new derivatives of a recently-reported class of irregular diterpene have been discovered in New Zealand species of the Apiaceae family. 16-Acetoxyanisotomenoic acid (8) (3,3a,4,4-tetramethyl-3-{(Z)-5-acetoxy-4-methyl-3-pentenyl}-2,3,3a,4,5,6-hexahydro-1H-2-indenecarboxylic acid) and anisotomene-1,12-diol (11) (3,3a,4,4-tetramethyl-3-(2-hydroxy-4-methyl-3-pentenyl)-2,3,3a,4,5,6-hexahydro-1H-2-indenyl) methanol) have been obtained from the sub-alpine plants, Anisotome flexuosa and A. haastii respectively. 13 C nuclear magnetic esonance (n.m.r.) spectra of the anisotomene derivatives are complicated by line broadening. Molecular modelling of anisotomenoic acid (1) and anisotomenol (2) suggests that this is due to conformational exchange in the highly substituted bicyclo [4,3,0] non-1-ene ring system.

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Alpine Plants of New Zealand

Ecology ◽

10.2307/1935480 ◽

1974 ◽

Vol 55 (6) ◽

pp. 1434-1435

Author(s):

Warren R. Keammerer

Keyword(s):

New Zealand ◽

Alpine Plants

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Phenotypic variation in mitochondrial function across New Zealand snail populations

10.1101/230979 ◽

2017 ◽

Author(s):

Emma S. Greimann ◽

Samuel F. Ward ◽

James D. Woodell ◽

Samantha Hennessey ◽

Michael R. Kline ◽

...

Keyword(s):

New Zealand ◽

Mitochondrial Function ◽

Energy Homeostasis ◽

Environmental Gradients ◽

Nuclear Genome ◽

Cellular Respiration ◽

Biological Organization ◽

Data Set ◽

Nuclear Interactions ◽

Nuclear Variation

ABSTRACTMitochondrial function is critical for energy homeostasis and should shape how genetic variation in metabolism is transmitted through levels of biological organization to generate stability in organismal performance. Mitochondrial function is encoded by genes in two distinct and separately inherited genomes – the mitochondrial genome and the nuclear genome – and selection is expected to maintain functional mito-nuclear interactions. Nevertheless, high levels of polymorphism in genes involved in these mito-nuclear interactions and variation for mitochondrial function are nevertheless frequently observed, demanding an explanation for how and why variability in such a fundamental trait is maintained. Potamopyrgus antipodarum is a New Zealand freshwater snail with coexisting sexual and asexual individuals and, accordingly, contrasting systems of separate vs. co-inheritance of nuclear and mitochondrial genomes. As such, this snail provides a powerful means to dissect the evolutionary and functional consequences of mito-nuclear variation. The lakes inhabited by P. antipodarum span wide environmental gradients, with substantial across-lake genetic structure and mito-nuclear discordance. This situation allows us to use comparisons across reproductive modes and lakes to partition variation in cellular respiration across genetic and environmental axes. Here, we integrated cellular, physiological, and behavioral approaches to quantify variation in mitochondrial function across a diverse set of wild P. antipodarum lineages. We found extensive across-lake variation in organismal oxygen consumption, mitochondrial membrane potential, and behavioral response to heat stress, but few global effects of reproductive mode or sex. Taken together, our data set the stage for applying this important model system for sexual reproduction and polyploidy to dissecting the complex relationships between mito-nuclear variation, performance, plasticity, and fitness in natural populations.

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Drivers of beta diversity in modern and ancient reef-associated soft-bottom environments

PeerJ ◽

10.7717/peerj.9139 ◽

2020 ◽

Vol 8 ◽

pp. e9139

Author(s):

Vanessa Julie Roden ◽

Martin Zuschin ◽

Alexander Nützel ◽

Imelda M. Hausmann ◽

Wolfgang Kiessling

Keyword(s):

Water Depth ◽

Beta Diversity ◽

Environmental Gradients ◽

Priority Effects ◽

Spatial Distance ◽

Late Triassic ◽

Minor Role ◽

Compositional Variation ◽

Soft Bottom ◽

Cassian Formation

Beta diversity, the compositional variation among communities, is often associated with environmental gradients. Other drivers of beta diversity include stochastic processes, priority effects, predation, or competitive exclusion. Temporal turnover may also explain differences in faunal composition between fossil assemblages. To assess the drivers of beta diversity in reef-associated soft-bottom environments, we investigate community patterns in a Middle to Late Triassic reef basin assemblage from the Cassian Formation in the Dolomites, Northern Italy, and compare results with a Recent reef basin assemblage from the Northern Bay of Safaga, Red Sea, Egypt. We evaluate beta diversity with regard to age, water depth, and spatial distance, and compare the results with a null model to evaluate the stochasticity of these differences. Using pairwise proportional dissimilarity, we find very high beta diversity for the Cassian Formation (0.91 ± 0.02) and slightly lower beta diversity for the Bay of Safaga (0.89 ± 0.04). Null models show that stochasticity only plays a minor role in determining faunal differences. Spatial distance is also irrelevant. Contrary to expectations, there is no tendency of beta diversity to decrease with water depth. Although water depth has frequently been found to be a key factor in determining beta diversity, we find that it is not the major driver in these reef-associated soft-bottom environments. We postulate that priority effects and the biotic structuring of the sediment may be key determinants of beta diversity.

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Plant radiation history affects community assembly: evidence from the New Zealand alpine

Biology Letters ◽

10.1098/rsbl.2011.1210 ◽

2012 ◽

Vol 8 (4) ◽

pp. 558-561 ◽

Cited By ~ 18

Author(s):

William G. Lee ◽

Andrew J. Tanentzap ◽

Peter B. Heenan

Keyword(s):

New Zealand ◽

Community Assembly ◽

Priority Effects ◽

Habitat Occupancy ◽

The Past ◽

Alpine Zone ◽

Age Related ◽

Bioclimatic Zone ◽

Alpine Plant Communities ◽

Radiation History

The hypothesis that early plant radiations on islands dampen diversification and reduce habitat occupancy of later radiations via niche pre-emption has never, to our knowledge, been tested. We investigated clade-level dynamics in plant radiations in the alpine zone, New Zealand. Our aim was to determine whether radiations from older colonizations influenced diversification and community dominance of species from later colonizations within a common bioclimatic zone over the past ca 10 Myr. We used stem ages derived from the phylogenies of 17 genera represented in alpine plant communities in the Murchison Mountains, Fiordland, and assessed their presence and cover in 262 (5 × 5 m) vegetation plots. Our results show clear age-related community assembly effects, whereby congenerics from older colonizing genera co-occur more frequently and with greater cover per unit area than those from younger colonizing genera. However, we find no evidence of increased species richness with age of colonization in the alpine zone. The data support priority effects via niche pre-emption among plant radiations influencing community assembly.

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Zooplankton biodiversity and community structure vary along spatiotemporal environmental gradients in restored peridunal ponds

Journal of Limnology ◽

10.4081/jlimnol.2015.1305 ◽

2015 ◽

Cited By ~ 2

Author(s):

Maria Anton-Pardo ◽

Xavier Armengol ◽

Raquel Ortells

Keyword(s):

Species Richness ◽

Environmental Gradients ◽

Life Cycles ◽

Priority Effects ◽

Weak Selection ◽

Temporal Dimension ◽

High Exposure ◽

Local Factors ◽

Dispersal Vectors ◽

Community Dissimilarity

<p>Zooplankton assemblages in neighboring ponds can show important spatial and temporal heterogeneity. Disentangling the influence of regional versus local factors, and of deterministic versus stochastic processes has been recently highlighted in the context of the metacommunity theory. In this study, we determined patterns of temporal and spatial variation in zooplankton diversity along one hydrological year in restored ponds of different hydroperiod and age. The following hypotheses regarding the assembling of species over time were tested: i) dispersal is not limited in our study system due to its small area and high exposure to dispersal vectors; ii) community dissimilarity among ponds increases with restoration age due to an increase in environmental heterogeneity and stronger niche-based assemblages;and iii) similarity increases with decreasing hydroperiod because hydroperiod is a strong selective force filtering out organisms with long life cycles. Our results confirmed dispersal as a homogenizing force and local factors as gaining importance with time of restoration. However, short hydroperiod ponds were highly dissimilar, maybe due to the environmental differences among these ponds, or to high stochasticity followed by priority effects under a weak selection pressure. By adding a temporal dimension to the study of zooplankton structuring, we could identify the first months after flooding as being crucial for species richness, especially in short hydroperiod ponds; and we detected differences in seasonal species richness related to hydroperiod and pond age.</p>

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Using novel metrics to assess biogeographic patterns of abrupt treelines in relation to abiotic influences

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133315569338 ◽

2015 ◽

Vol 39 (3) ◽

pp. 310-336 ◽

Cited By ~ 3

Author(s):

Bradley S. Case ◽

Roddy J. Hale

Keyword(s):

New Zealand ◽

Environmental Gradients ◽

Variance Partitioning ◽

Landscape Scale ◽

Biogeographic Patterns ◽

Alpine Treeline ◽

Comprehensive Picture ◽

The Individual ◽

Abiotic Influences ◽

Scale Variation

Alpine treeline ecotones display spatial variability in a range of features that often reflect underlying abiotic variation and its control on the processes that form and maintain treelines. In this study, we explore treeline pattern–environment relationships for continuous, abrupt Nothofagus treelines in New Zealand across a seven degree latitudinal gradient (circa 39–46° S). Our main aims were: 1) to develop a set of metrics for characterising spatial variation in abrupt treelines at a landscape scale; 2) to relate these metrics to underlying abiotic variation in order to determine the relative roles of climate, substrate, topography and disturbance in structuring Nothofagus treeline patterns; and 3) to develop a possible biogeographic typology of Nothofagus treelines. A GIS-based approach was used to develop seven metrics describing different facets of landscape-scale treeline pattern. Regression modelling and variance partitioning were used to explore relationships among treeline pattern metrics and abiotic variation. Cluster analysis was used to characterise emergent treeline types and GIS was used to map their biogeographic distributions. The individual treeline metrics characterised unique patterns of treeline variation across New Zealand and, upon clustering, resulted in seven distinctive treeline types. Nothofagus treeline patterns in New Zealand are strongly structured by environmental gradients, with about half the landscape-scale variation in treelines being structured by patterns of abiotic variation. Gradients of climatic and disturbance were most influential in explaining landscape-scale variation of individual treeline metrics and of multivariate treeline patterns. The presented, metric-based approach offers a means to develop a comprehensive picture of continuous, landscape-scale treeline variation, bridging an existing research gap between studies at site and global scales. Our approach can enable the development biogeographic treeline typologies that could facilitate the comparison of treeline patterns across large areas and provide a basis for the generation of new hypotheses regarding treeline formation and dynamics.

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