scholarly journals Realised Niche Shifts, Rapid Evolution and Phenotypic Plasticity in Introduced Plants

2021 ◽  
Author(s):  
◽  
Charles Daniel Clark
Keyword(s):  
New Zealand ◽  
Phenotypic Plasticity ◽  
Introduced Species ◽  
Effect Size ◽  
Rapid Evolution ◽  
Niche Shift ◽  
Herbarium Specimens ◽  
Climate Niche ◽  
Niche Shifts ◽  
Glasshouse Experiment

<p>Recent biological invasions provide a unique opportunity to examine how species may adapt to novel conditions over relatively short time frames. Introduced species may respond to novel environmental conditions in the new range via rapid evolution, phenotypic plasticity, or the rapid evolution of phenotypic plasticity. However, the prevalence of these different mechanisms in introduced species remains unclear. In this thesis, I explore how introduced plant species may adjust their phenotype when introduced to a new range.  First, I tested for evidence of phenotypic change through time in key morphological traits (plant height, leaf area, leaf shape, and leaf mass per unit area), using historic herbarium records for 34 plants introduced to Australia and New Zealand. Thirty-two out of 94 trait-species combinations showed evidence for change through time. The rate and direction of trait change was variable across species and the local climate. One possibility is that species introduced to a new range exhibit different trait responses depending on the relative difference in environment between the native and introduced range. To investigate this, I quantified climatic niche shifts in introduced species relative to their native range. I then predicted trait change through time from the magnitude and direction of climate niche shift in a meta-regression. This is the first study to simultaneously assess trait change in multiple introduced species in relation to a shift in their realised niche. Overall, climate niche shifts did not predict trait change through time, suggesting that climate may not be the predominant driver of trait change in plants introduced to Australia and New Zealand. Alternatively, the combined uncertainty and the mismatch in spatial scales that may arise when combining these two methods could mask any underlying patterns in plant trait responses to the new environment.  It has been hypothesised that introduced species may respond to a sudden change in environment, by rapidly selecting for an increase in phenotypic plasticity. I tested for a difference in phenotypic plasticity between the native and introduced ranges of a beach daisy, Arctotheca populifolia. Contrary to my expectations, A. populifolia has shown a loss of phenotypic plasticity in as little as 80 years since its introduction to Australia. When using a meta-analysis to test for an overall difference in plasticity across multiple traits, I found that the current practice of calculating an effect size of an effect size (Hedges’ d) can lead to misleading results. I demonstrate how this issue arises when calculating a difference in Hedges’ d between two populations with different standard deviations. I propose an alternative way to calculate Hedges’ d to give a more accurate reflection of the difference in plasticity between ranges.  Finally, I combine different lines of evidence from the previous chapters in a case study to explore how A. populifolia has changed since its introduction to Australia, and examine any discrepancies between the results. A glasshouse experiment revealed distinct trait differences between native and introduced populations of A. populifolia, which were not reflected in trait change through time inferred from herbarium specimens. Additionally, measured trait differences between ranges in the glasshouse experiment better reflected a niche shift into wetter climate, than the predicted trait change through time from herbarium specimens. This suggests that trait differences determined in glasshouse or common garden experiments, may be a more suitable approach to assess trait change in relation to a realised niche shift than using herbarium specimens.</p>

scholarly journals Realised Niche Shifts, Rapid Evolution and Phenotypic Plasticity in Introduced Plants

2021 ◽  
Author(s):  
◽  
Charles Daniel Clark
Keyword(s):  
New Zealand ◽  
Phenotypic Plasticity ◽  
Introduced Species ◽  
Effect Size ◽  
Rapid Evolution ◽  
Niche Shift ◽  
Herbarium Specimens ◽  
Climate Niche ◽  
Niche Shifts ◽  
Glasshouse Experiment

<p>Recent biological invasions provide a unique opportunity to examine how species may adapt to novel conditions over relatively short time frames. Introduced species may respond to novel environmental conditions in the new range via rapid evolution, phenotypic plasticity, or the rapid evolution of phenotypic plasticity. However, the prevalence of these different mechanisms in introduced species remains unclear. In this thesis, I explore how introduced plant species may adjust their phenotype when introduced to a new range.  First, I tested for evidence of phenotypic change through time in key morphological traits (plant height, leaf area, leaf shape, and leaf mass per unit area), using historic herbarium records for 34 plants introduced to Australia and New Zealand. Thirty-two out of 94 trait-species combinations showed evidence for change through time. The rate and direction of trait change was variable across species and the local climate. One possibility is that species introduced to a new range exhibit different trait responses depending on the relative difference in environment between the native and introduced range. To investigate this, I quantified climatic niche shifts in introduced species relative to their native range. I then predicted trait change through time from the magnitude and direction of climate niche shift in a meta-regression. This is the first study to simultaneously assess trait change in multiple introduced species in relation to a shift in their realised niche. Overall, climate niche shifts did not predict trait change through time, suggesting that climate may not be the predominant driver of trait change in plants introduced to Australia and New Zealand. Alternatively, the combined uncertainty and the mismatch in spatial scales that may arise when combining these two methods could mask any underlying patterns in plant trait responses to the new environment.  It has been hypothesised that introduced species may respond to a sudden change in environment, by rapidly selecting for an increase in phenotypic plasticity. I tested for a difference in phenotypic plasticity between the native and introduced ranges of a beach daisy, Arctotheca populifolia. Contrary to my expectations, A. populifolia has shown a loss of phenotypic plasticity in as little as 80 years since its introduction to Australia. When using a meta-analysis to test for an overall difference in plasticity across multiple traits, I found that the current practice of calculating an effect size of an effect size (Hedges’ d) can lead to misleading results. I demonstrate how this issue arises when calculating a difference in Hedges’ d between two populations with different standard deviations. I propose an alternative way to calculate Hedges’ d to give a more accurate reflection of the difference in plasticity between ranges.  Finally, I combine different lines of evidence from the previous chapters in a case study to explore how A. populifolia has changed since its introduction to Australia, and examine any discrepancies between the results. A glasshouse experiment revealed distinct trait differences between native and introduced populations of A. populifolia, which were not reflected in trait change through time inferred from herbarium specimens. Additionally, measured trait differences between ranges in the glasshouse experiment better reflected a niche shift into wetter climate, than the predicted trait change through time from herbarium specimens. This suggests that trait differences determined in glasshouse or common garden experiments, may be a more suitable approach to assess trait change in relation to a realised niche shift than using herbarium specimens.</p>

scholarly journals Invasion but not hybridisation is associated with ecological niche shift in monkeyflowers

2019 ◽  
Author(s):  
Daniele Da Re ◽  
Angel P. Olivares ◽  
William Smith ◽  
Mario Vallejo-Marín
Keyword(s):  
New Zealand ◽  
Ecological Niche ◽  
Secondary Contact ◽  
Niche Shift ◽  
Ecological Niches ◽  
Introduced Populations ◽  
Niche Dynamics ◽  
Introduced Range ◽  
Niche Shifts ◽  
Native And Introduced Ranges

AbstractBackgroundThe ecological niche occupied by novel hybrids can influence their establishment as well as the potential to coexist with their parents. Hybridisation generates new phenotypic combinations, which, in some cases, may allow them to occupy ecological niches outside the environmental envelope of parental taxa. In other cases, hybrids may retain similar ecological niches to their parents, resulting in competition and affecting their coexistence. To date, few studies have quantitatively assessed niche shifts associated with hybridisation in recently introduced populations while simultaneously characterising the niche of parental species in both native and introduced ranges.AimsIn this study, we compared the ecological niche of a novel hybrid plant with the niches of its two parental taxa in the non-native geographic range. We also characterised and compared the parental taxa’s ecological niche of native and introduced populations in order to assess potential niche changes during the invasion process independent of hybridisation.MethodsWe studied monkeyflowers (Mimulus spp., Phrymaceae) that were introduced from the Americas to Europe and New Zealand in the last 200 years. We focused on a novel hybrid, triploid, asexual taxon (M. × robertsii) that occurs only in the British Isles where its two parents (M. guttatus and M. luteus) come into secondary contact. We assembled more than 12,000 geo-referenced occurrence records and eight environmental variables of the three taxa across native and introduced ranges, and conducted ecological niche model analysis using maximum entropy, principal component and niche dynamics analysis.ResultsWe found no evidence of niche shift in the hybrid, M. × robertsii compared to introduced populations of both of their parental taxa. The hybrid had a niche more similar to M. luteus, which is also the rarest of the parental taxa on the introduced range. Among parental monkeyflowers, M. guttatus showed niche conservatism in introduced populations in Europe, but a niche shift in New Zealand, while M. luteus showed a niche shift in Europe. However, the evidence of niche shift should be treated with caution due to the occurence of non-analog climatic conditions, small population size and unfilling niche dynamics.ConclusionsOur results suggest that hybridisation in non-native monkyeflowers did not result in a shift in ecological niche. This niche conservation could create competition between parental and derived taxa, the outcome of which will depend on relative competitive abilities. Further work is needed to establish if the expansion of the hybrid in the introduced range is causally related to the apparent rarity of one of the parents (M.luteus). Finally, the comparison of native and non-native populations of parental taxa, suggest that whether invasions result in niche shifts or not depends on both taxon and geographic region, highlighting the idiosyncratic nature of biological invasions.

Climatic niche shifts in introduced species

2021 ◽  
Vol 31 (19) ◽  
pp. R1252-R1266
Author(s):  
Olivia K. Bates ◽  
Cleo Bertelsmeier
Keyword(s):  
Introduced Species ◽  
Climatic Niche ◽  
Niche Shifts

scholarly journals Ulva,UmbraulvaandGemina: genetic survey of New Zealand taxa reveals diversity and introduced species

2009 ◽  
Vol 44 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Svenja Heesch ◽  
Judy E.S. Broom ◽  
Kate F. Neill ◽  
Tracy J. Farr ◽  
Jennifer L. Dalen ◽  
...  
Keyword(s):  
New Zealand ◽  
Introduced Species ◽  
Genetic Survey

scholarly journals The key roles of seed banks in plant biodiversity management in New Zealand

2010 ◽  
Vol 14 ◽  
pp. 5-11
Author(s):  
W.M. Williams
Keyword(s):  
New Zealand ◽  
Introduced Species ◽  
Intrinsic Value ◽  
Seed Banks ◽  
Indigenous Species ◽  
Plant Biodiversity ◽  
Biodiversity Management ◽  
Recent Initiative ◽  
New Zealand Flora ◽  
Pasture Plants

The New Zealand flora is a mixture of indigenous and introduced species. The indigenous species have a high intrinsic value while the introduced species include all of the crop and pasture plants upon which the export-led economy depends. New Zealand must maintain both of these important sources of biodiversity in balance. Seed banks are useful tools for biodiversity management. In New Zealand, a seed bank for indigenous species has been a very recent initiative. By contrast, seed banks for introduced species have been established for over 70 years. The reasons for this discrepancy are discussed. For the economic species, conserved genetic diversity is used to enhance productivity and the environment. Large advances can be gained from species that are not used as economic plants. The gene-pool of white clover has been expanded by the use of minor species conserved as seeds in the Margot Forde Germplasm Centre. Keywords: Seed banks, biodiversity conservation, New Zealand flora

Genetic variation in Trithuria inconspicua and T. filamentosa (Hydatellaceae): a new subspecies and a hypothesis of apomixis arising within a predominantly selfing lineage

2019 ◽  
Author(s):  
Rob D. Smissen ◽  
Kerry A. Ford ◽  
Paul D. Champion ◽  
Peter B. Heenan
Keyword(s):  
Genetic Variation ◽  
New Zealand ◽  
Morphological Variation ◽  
Genetic Distances ◽  
Herbarium Specimens ◽  
Minimum Evolution ◽  
The North ◽  
Genetic Groups ◽  
Morphological Differences ◽  
High Level

While examining herbarium specimens of Trithuria inconspicua Cheeseman, we observed differences in the stigmatic hairs among plants from New Zealand’s North and South Islands. This motivated us to assess genetic and morphological variation within this species and its sister T. filamentosa Rodway from Tasmania. Samples were collected from lakes in the three disjunct geographic areas where the two species occur. Genetic variation in both species was assessed with simple sequence-repeat (SSR, microsatellite) markers and analyses of genetic distances. We also compared the morphology of northern and southern New Zealand T. inconspicua using fresh material. Samples of each species clustered together in a minimum evolution tree built from genetic distances. Trithuria filamentosa had more genetic diversity than did T. inconspicua. Within T. inconspicua, plants from lakes in the North Island and the South Island formed discrete genetic groups diagnosable by subtle morphological differences. Low levels of heterozygosity in both species are consistent with a high level of selfing, as suggested for other co-sexual Trithuria species, but unusual for a putative apomict. On the basis of genetic and morphological variation, we propose recognition of the northern New Zealand and southern New Zealand lineages of T. inconspicua at subspecies rank.

CENOZOIC PLANKTONIC FORAMINIFERAL ZONATIONS OF SOUTHERN AUSTRALIA AND NEW ZEALAND

1975 ◽  
Vol 15 (2) ◽  
pp. 42
Author(s):  
D. Graham Jenkins
Keyword(s):  
New Zealand ◽  
Rapid Development ◽  
Planktonic Foraminifera ◽  
Rapid Evolution ◽  
South Australia ◽  
Research Programme ◽  
Oil Exploration ◽  
Major Step ◽  
Fossil Species ◽  
A Minor

BIOSTRATIGRAPHIC DOCUMENTATION of fossil species of planktonic foraminifera has played a major role in correlating marine Cenozoic rocks because of their relatively high diversity, abundance, rapid evolution and wide geographic distribution. A major step was undertaken in Trinidad in 1945 with the division of the Oligocene-Miocene rocks into three zones based on planktonic foraminifera and with the intensive oil-search on the island, there began an equally intensive research programme and rapid development in the study.Two research projects, independent of each other, were initiated in Gippsland. Victoria in the 1950s which resulted in publications: (1) from surface samples, a faunal unit system was devised for the Upper Eocene-Miocene. and (2) 11 named planktonic foraminiferal zones were established in a four-foot sampled Oligocene-Miocene sequence of the Lakes Entrance oil shaft. The latter scheme was tested and expanded for 3 years during oil exploration on the East Coast of New Zealand during 1959-1962 and a further four years was spent thoroughly testing, and expanding it into 21 zones sub-dividing the whole Cenozoic time of 67my. The zones can be identified in both surface and sub-surface sections and used for direct, accurate correlations of marine rock sequences thus providing the geologist with essential data for the construction of maps and subsurface control.The zonal scheme was re-exported back to South Australia, later to Gippsland and used there with minor local changes in the off-shore oil exploration; in 1973 the zonal scheme was further tested during the Deep Sea Drilling Project Leg 29 in the area south of New Zealand and Australia.Studies of planktonic foraminifera and allied microfossils has resulted in the cheapest and most reliable method for rapid age determinations of Cenozoic marine rocks; in perspective it plays a minor, but essential role in oil-search. The zonal scheme is a dynamic model subject to change and improvement.

Endophytic Fungi in Indigenous Australasian Grasses Associated with Toxicity to Livestock

1998 ◽  
Vol 64 (2) ◽  
pp. 601-606 ◽  
Author(s):  
Christopher O. Miles ◽  
Margaret E. di Menna ◽  
Surrey W. L. Jacobs ◽  
Ian Garthwaite ◽  
Geoffrey A. Lane ◽  
...  
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
High Performance ◽  
Ergot Alkaloids ◽  
Enzyme Linked Immunosorbent Assay ◽  
Herbarium Specimens ◽  
Causative Agents ◽  
Listronotus Bonariensis ◽  
First Time ◽  
Slow Growing

ABSTRACT Grazing of Echinopogon spp. by livestock in Australia has caused symptoms similar to those of perennial ryegrass staggers. We observed an endophytic fungus in the intercellular spaces of the leaves and seeds of New Zealand and Australian specimens of Echinopogon ovatus. Culture of surface-sterilized seeds from New Zealand specimens yielded a slow-growing fungus. An examination in which immunoblotting and an enzyme-linked immunosorbent assay (ELISA) were used indicated that E. ovatus plants from Australia and New Zealand were infected with fungi serologically related toNeotyphodium lolii (the endophyte of perennial ryegrass) and other Epichloe and Neotyphodium spp. endophytic in pooid grasses. No lolitrems (the indole–diterpenoids implicated as the causative agents of perennial ryegrass staggers), peramine analogs, or ergot alkaloids were detected in the infected specimens by high-performance liquid chromatography or ELISA. However, in endophyte-infected E. ovatus plants from New Zealand, analogs of the indole–diterpenoid paxilline (thought to be a biosynthetic precursor of the lolitrems and related tremorgens) were detected by ELISA, and N-formylloline was detected by gas chromatography. Endophyte-free specimens of New Zealand E. ovatus did not contain detectable paxilline analogs or lolines and were more palatable than infected specimens to adults of the pasture pest Listronotus bonariensis (Argentine stem weevil). Hyphae similar to those of the E. ovatus endophyte were also found in herbarium specimens of Echinopogon nutans var. major, Echinopogon intermedius, Echinopogon caespitosus, andEchinopogon cheeli. This appears to be the first time that an endophytic Neotyphodium species has been identified in grasses endemic to New Zealand or Australia.

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