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

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.

2016 ◽  
Vol 38 (5) ◽  
pp. 511 ◽  
Author(s):  
Zhao Na ◽  
Wang Zhengwen ◽  
Shao Xinqing ◽  
Wang Kun

The diversity–stability relationship has been addressed and debated for decades, but how this relationship is affected by nutrient availability remains contentious. In the present study we assessed the effects of plant diversity, in terms of species richness, functional group composition and functional trait diversity, on the spatial stability of net primary productivity (NPP) following nitrogen and phosphorus application. In addition, we explored how functional traits at the species level contribute to the spatial stability of NPP. The results support the hypothesis that greater diversity leads to higher spatial stability. This relationship was highly dependent on soil nutrient availability, and increasing species richness or functional trait diversity significantly increased spatial variation of NPP under a high N fertilisation level. The effects of high mineral fertilisation rates may perhaps have masked the effects of plant diversity. Although species richness or functional trait diversity of the original and modified communities from which species with particular functional traits had been removed were significantly different, there were no differences in the coefficients of variation in the NPP of those communities. The lack of difference demonstrated that the relationship between spatial variability and biodiversity depended on the measure of diversity applied and that the functional group composition exerted a stronger effect than other diversity measures. Further analyses revealed that spatial stability of NPP was enhanced with increased diversity in vegetative plant height, rooting depth and the presence of legume, and diminished with diversity in the root system type and life cycle under some fertilisation treatments. The present study demonstrates that the relationship between biodiversity and ecosystem functioning is variable with different diversity, identity and environmental factors. Evaluating the contribution of particular traits to community stability will ultimately help us better understand the mechanisms underlying the diversity–stability relationship.


2012 ◽  
Vol 124 (1) ◽  
pp. 47
Author(s):  
Alan York

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
John T. Hunter

Inselbergs and the adjacent matrix represent extremes of different environmental conditions and should shed light on the changing allocation of plant resources across strong and abrupt resource gradients. Here I use collated life history trait data from 840 taxa found within typical insular inselberg and adjacent matrix floras from the New England Batholith region of eastern Australia. These species were sorted into guilds of specificity to the inselberg environment. Scored traits include life form, plant height, leaf area, fruit size, seed size, mono- or polycarpy, underground storage organs, regenerative/clonality, and flowering phenology. With reduced water and nutrient resources, typical of inselbergs, allocation of plant resources to vegetative reproduction and storage organs is a disadvantage. Plants restricted to inselbergs were shorter, usually polycarpic shrubs, with smaller leaves, fruits, and seeds. Flowering time was found to be earlier and reduced in length; diaspores often have dormancy and are dispersed locally in comparison to the matrix. The results show that with limited resources the creation of underground storage organs or vegetative reproduction becomes unviable on habitats characterised by shallow soil. Inselberg taxa of the study region are likely to be under greater threat than the matrix due to anthropogenic climate change.


2004 ◽  
Vol 55 (3) ◽  
pp. 295 ◽  
Author(s):  
A. J. Richardson ◽  
J. E. Growns ◽  
R. A. Cook

Caridean shrimps are an integral component of lowland river ecosystems in south-eastern Australia, but their distributions may be affected by flow alteration. Monthly shrimp samples were collected from slackwaters in three hydrologically distinct sections of the heavily regulated Campaspe River and the less regulated Broken River for three consecutive years. The distributions of Paratya australiensis, Caridina mccullochi and Macrobrachium australiense, along with their life history in river sections with different hydrology are outlined. Paratya australiensis and M. australiense occurred in all sections, but C. mccullochi was absent from sections of the Campaspe River that received irrigation flows during summer/autumn. Shrimp larvae were most abundant in summer (December–February) and juvenile recruitment continued through to mid autumn (April). Breeding and recruitment of P. australiensis occurred for longer than other shrimps. Apart from large adult and berried M. australiense, all life stages of shrimps commonly occurred in slackwaters, particularly the larval and juvenile stages. Irrigation flows in summer/autumn probably adversely affect the size, extent and arrangement of slackwaters, at a time when they may be critical habitats for C. mccullochi larval development and recruitment. Dams and weirs in the Campaspe River may have influenced shrimp abundance and the timing of breeding.


2021 ◽  
Vol 12 ◽  
Author(s):  
Caishuang Huang ◽  
Yue Xu ◽  
Runguo Zang

Understanding how environmental change alters the composition of plant assemblages is a major challenge in the face of global climate change. Researches accounting for site-specific trait values within forest communities help bridge plant economics theory and functional biogeography to better evaluate and predict relationships between environment and ecosystem functioning. Here, by measuring six functional traits (specific leaf area, leaf dry matter content, leaf nitrogen, and phosphorus concentration, leaf nitrogen/phosphorus, wood density) for 292 woody plant species (48,680 individuals) from 250 established permanent forest dynamics plots in five locations across the subtropical evergreen broadleaved forests (SEBLF) in China, we quantified functional compositions of communities by calculating four trait moments, i.e., community-weighted mean, variance, skewness, and kurtosis. The geographical (latitudinal, longitudinal, and elevational) patterns of functional trait moments and their environmental drivers were examined. Results showed that functional trait moments shifted significantly along the geographical gradients, and trait moments varied in different ways across different gradients. Plants generally showed coordinated trait shifts toward more conservative growth strategies (lower specific leaf area, leaf N and P concentration while higher leaf nitrogen/phosphorus and wood density) along increasing latitude and longitude. However, trends opposite to the latitudinal and longitudinal patterns appeared in trait mean values along elevation. The three sets of environmental variables (climate, soil and topography) explained 35.0–69.0%, 21.0–56.0%, 14.0–31.0%, and 16.0–30.0% of the variations in mean, variance, skewness, and kurtosis across the six functional traits, respectively. Patterns of shifts in functional trait moments along geographical gradients in the subtropical region were mainly determined by the joint effects of climatic and edaphic conditions. Climate regimes, especially climate variability, were the strongest driving force, followed by soil nutrients, while topography played the least role. Moreover, the relationship of variance, skewness and kurtosis with climate and their geographical patterns suggested that rare phenotypes at edges of trait space were selected in harsher environments. Our study suggested that environmental filtering (especially climate variability) was the dominant process of functional assembly for forest communities in the subtropical region along geographical gradients.


2016 ◽  
Vol 67 (4) ◽  
pp. 409 ◽  
Author(s):  
R. D. Brill ◽  
M. L. Jenkins ◽  
M. J. Gardner ◽  
J. M. Lilley ◽  
B. A. Orchard

April sowing of canola is considered optimal for grain yield in many regions of Australia; however, there is often insufficient rainfall in April to sow seed into moisture at the ideal depth of 15–30 mm. We report a series of experiments that investigated the seed characteristics (cultivar type and seed size) that would facilitate successful canola emergence from relatively deep sowing (>30 mm). Ten canola cultivar by sowing depth experiments, each with three hybrid and three open-pollinated cultivars, found hybrid cultivars were able to maintain higher emergence rates and grain yield compared with open-pollinated cultivars from deep sowing. Further investigations in the glasshouse showed that the emergence advantage of the hybrid cultivars was largely due to their inherently large seed size, as increased seed size also improved emergence of open-pollinated canola. Early biomass accumulation also improved with larger seeds. In a field experiment, larger seed size of both hybrid and open-pollinated canola increased early biomass accumulation and final grain yield. Simulation modelling in New South Wales demonstrated the importance of timely sowing of canola, as delayed sowing caused a larger reduction in grain yield than reduced plant population. Although ‘moisture-seeking’ (placing seed into moist soil below a layer of dry soil) reduced the emergence rate of canola, the reduction could be offset by planting large seed (>2 mm diameter). This practice of ‘moisture-seeking’ large-seeded canola should be considered as a strategy to improve the timeliness of establishment and subsequent grain yield of canola when rainfall for crop establishment is marginal yet there is moisture available deeper in the seedbed.


2014 ◽  
Vol 328 ◽  
pp. 1-9 ◽  
Author(s):  
Matthew B. Russell ◽  
Christopher W. Woodall ◽  
Anthony W. D’Amato ◽  
Grant M. Domke ◽  
Sassan S. Saatchi

2021 ◽  
Author(s):  
Carlos Aguilar-Trigueros ◽  
Mark Fricker ◽  
Matthias Rillig

<p>Fungal mycelia consist of an interconnected network of filamentous hyphae and represent the dominant phase of the lifecycle in all major fungal phyla, from basal to more recent clades. Indeed, the ecological success of fungi on land is partly due to such filamentous network growth. Nevertheless, fungal ecologists rarely use network features as functional traits. Given the widespread occurrence of this body type, we hypothesized that interspecific variation in network features may reflect both phylogenetic affiliation and distinct ecological strategies among species. We show first that there is high interspecific variation in network parameters of fungi, which partly correlates with taxonomy; and second that network parameters, related to predicted-mycelial transport mechanisms during the exploration phase, reveal the trait space in mycelium architecture across species.  This space predicts a continuum of ecological strategies along two extremes: from highly connected mycelia with high resilience to damage but limited transport efficiency, to poorly connected mycelia with low resilience but high transport efficiency. We argue that mycelial networks are potentially a rich source of information to inform functional trait analysis in fungi, but we also note the challenges in establishing common principles and processing pipelines that are required to facilitate widespread use of network properties as functional traits in fungal ecology.</p>


Sign in / Sign up

Export Citation Format

Share Document