scholarly journals Invertebrates and fire—challenges and opportunities for conserving biodiversity

2012 ◽  
Vol 124 (1) ◽  
pp. 47
Author(s):  
Alan York
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Fire Management ◽  
Vascular Plant ◽  
Natural Ecosystems ◽  
Terrestrial Invertebrates ◽  
Invertebrate Biodiversity ◽  
Composition And Structure ◽  
Eastern Australia ◽  
Challenges And Opportunities

Fires, whether planned or unplanned, impact upon a suite of organisms in natural ecosystems. Direct (short-term) and indirect (longer term) effects influence the composition and structure of invertebrate communities through the interaction of site history, characteristics of individual fire events and species life-history traits. Prediction of fire responses based on vascular plant species life-history traits, and the development of a functional classification based on shared traits, underpins current fire management in south-eastern Australia. Can a similar approach be developed for terrestrial invertebrates, or should we focus on utilising a framework based on surrogates developed around vegetation composition and structure, or taxonomic alternatives? This paper considers whether the use of surrogates offers promise as a strategy of dealing with the complexity of invertebrate biodiversity and associated issues surrounding fire management. It proposes a functional approach, based on species’ life-history traits, that can complement existing strategies; and identifies opportunities that have potential for resolving existing challenges in biodiversity conservation in fire-prone environments.

Differences in disturbance type and nutrient availability favour different functional traits across three co-occurring montane wetland systems in eastern Australia

2016 ◽  
Vol 64 (6) ◽  
pp. 526 ◽  
Author(s):  
John T. Hunter
Keyword(s):  
Life History ◽  
Seed Size ◽  
Functional Traits ◽  
Nutrient Availability ◽  
Vascular Plant ◽  
Fruit Size ◽  
Functional Trait ◽  
Freshwater Wetland ◽  
Disturbance Regime ◽  
Eastern Australia

Three co-occurring temperate montane non-riparian freshwater wetland communities of the New England Batholith of eastern Australia were chosen to test differences in resource allocation to select functional traits. Each of the wetlands was tested against inferred gradients of nutrient availability, fire and disturbance frequency. Collated functional trait data on 563 native vascular plant taxa known to occur in bogs, fens and lagoons were used against a centrally weighted means redundancy analysis. Traits included life form, plant height, leaf area, fruit size, seed size, mono- or polycarpy, storage organs, fruit type, vegetative spread and geographic range size. Where disturbances were moderate to low in frequency and habitats persistent, tolerance and in-situ permanence traits were favoured. With high nutrient availability and a low disturbance regime polycarpic species with large leaves that allow for larger fruit development were more common. Under low nutrient availability and a moderate disturbance regime, persistence was shifted to a longer lived polycarpic life history that includes woody taxa with increased seed size and a greater diversity of fruit types. In frequently inundated habitats, with shifting windows of available habitats, avoidance was the best strategy. Here persistence shifts to long-lived soil stored diaspores and a monocarpic life history with rapid vegetative growth to capture above ground spatial resource within temporary habitats.

Reproductive compensation in female Palaemonetes argentinus (Decapoda: Natantia) due to Microphallus szidati (Trematoda) infection

2020 ◽  
Vol 94 ◽  
Author(s):  
M. Parietti ◽  
M.J. Merlo ◽  
M. Natal ◽  
M.A. Méndez Casariego
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Dry Weight ◽  
Compensatory Response ◽  
Composition And Structure ◽  
Functional Part ◽  
Embryonic Loss ◽  
Reproductive Compensation ◽  
Living Organisms ◽  
Incomplete Picture

Abstract Parasites may affect host demographic characteristics because they can directly or indirectly cause the death of their hosts and/or influence their reproduction. Parasitism is therefore recognized as a factor that influences the composition and structure of populations and communities. One of these behaviours is the compensatory response: the host can compensate for the parasite losses effect, modifying the reproductive effort to enhance fitness. Ovigerus female Palaemonetes argentinus was collected and sorted into two groups according to the degree of development of their embryos: newly spawned embryos and embryos ready to hatch. The number of embryos and their dry weight for each female were determined. All parts of the female body were checked for parasites. The females of P. argentinus were parasitized by Microphalus szidati. We found that parasitized females produce more embryos but had more egg loss during development and the percentage of embryonic loss was higher in the parasitized females than in non-parasitized. Parasitized females produced lighter eggs than those from uninfected females. This supports the compensatory reproduction hypothesis suggested for this species. Parasitism can change life history traits in a way that fecundity can be compensated; this co-evolution between host and parasites will be population or context dependent. Parasites are a functional part of any ecosystem and as our results show, deleting parasites in life history traits and reproduction studies in free living organisms could lead to an incomplete picture of the true processes that happen in nature.

Regional differences in the reproductive parameters of the sparsely-spotted stingaree, Urolophus paucimaculatus, from south-eastern Australia

2014 ◽  
Vol 65 (11) ◽  
pp. 943 ◽  
Author(s):  
Fabian I. Trinnie ◽  
Terence I. Walker ◽  
Paul L. Jones ◽  
Laurie J. Laurenson
Keyword(s):  
Life History ◽  
Annual Cycle ◽  
Regional Differences ◽  
Life History Traits ◽  
Size At Maturity ◽  
Reproductive Parameters ◽  
Maternal Condition ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Whether spatial variation occurs in the life-history traits of chondrichthyan species is important to fisheries modelling and assessments. A study on the reproductive parameters of Urolophus paucimaculatus from four separate regions across south-eastern Australia found regional differences in maximum total length (TL), size-at-maturity, size-at-maternity and litter sizes. Inshore embayments (Port Phillip Bay (PPB) and Corner Inlet (CI)) appear to allow for larger TLs (females and males) than do offshore areas (Lakes Entrance (LE) and Western Bass Strait (WBS)). Size-at-maturity and size-at-maternity decreased across longitude from west (PPB) to east (LE) and seasonality of parturition and ovulation occurred earlier in PPB (August–October) than in LE (September–December). Maximum litter size correlated with maximum TL (six in PPB, five in each of CI and LE, and four in WBS). There was uncertainty in classifying females for maternal condition because the reproductive cycle appears to range from a continuous annual cycle to a non-continuous biennial cycle. Much of the uncertainty arises from the ambiguity of observation of non-pregnant mature females, which have either aborted through capture and handling, or are in a ‘resting year’ between pregnancies. Most likely, the majority are reproducing annually with an unknown proportion of females non-continuous and resting between pregnancies.

Reproduction and population ecology of the vulnerable western sawshelled turtle, Myuchelys bellii, in the Murray–Darling Basin, Australia

2014 ◽  
Vol 62 (6) ◽  
pp. 463 ◽  
Author(s):  
Darren P. Fielder ◽  
Duncan J. Limpus ◽  
Colin J. Limpus
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Species Abundance ◽  
Growth Increment ◽  
Turtle Species ◽  
Management Actions ◽  
Fundamental Information ◽  
Murray Darling Basin ◽  
Eastern Australia ◽  
In The Wild

Effective management decisions about the conservation of threatened species often rely on good information about their biology and life-history traits. Nearly half of all turtle species face extinction in the wild through worldwide rapid declines in species abundance and habitat loss. The vulnerable western sawshelled turtle, Myuchelys bellii, from eastern Australia is one such species under threat and for which fundamental information is lacking. The three known populations of M. bellii in the Murray–Darling Basin from the Namoi, Gwydir and Border Rivers catchments were studied over a period of nearly eight years. From capture–mark–recapture data, we studied M. bellii’s sexual maturity and reproduction, compared age of individuals using growth rates derived from annuli and growth increment data and calculated a population estimate for the Queensland population. For the first time this study has quantified the life-history traits of M. bellii including having delayed age at first breeding, with males taking nearly 10 years to mature and females approaching 20 years (from growth increment data), low reproductive effort (14.3 eggs per adult female; 78% of females breeding in any one year) and high survivorship with a predicted lifespan of over 40 years. Of particular management concern for M. bellii is the long-term conservation of the small isolated Queensland population (<400 individuals). The extensive dataset provides a baseline for future investigations and management actions required to improve the conservation outcomes for this threatened turtle.

scholarly journals Hybridization and diversification are positively correlated across vascular plant families

2019 ◽  
Author(s):  
Nora Mitchell ◽  
Kenneth D. Whitney
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Causal Structure ◽  
Vascular Plant ◽  
Diversification Rates ◽  
Future Studies ◽  
Family Level ◽  
History Information ◽  
Plant Families ◽  
The Relationship

ABSTRACTHybridization has experimental and observational ties to evolutionary processes and outcomes such as adaptation, speciation, and radiation. Although it has been hypothesized that hybridization and diversification are correlated, this idea remains largely untested empirically. Here, we use a hybridization database on 195 plant families, life history information, and a time-calibrated family-level phylogeny to test for phylogenetically-corrected associations between hybridization and diversification rates, while also taking into account life-history traits that may be correlated with both processes. We show that diversification and hybridization are positively correlated using three different methods to estimate diversification rates and two different metrics of hybridization. Moreover, the relationship remains detectable when incorporating the correlations between diversification and two other life history characteristics, perenniality and woodiness. We further provide potential mechanisms for this association under three different scenarios: hybridization may drive diversification, diversification may drive hybridization, or both hybridization and diversification may jointly be driven by other factors. We suggest future studies to disentangle the causal structure.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

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