Evolution and Ecology Research Center

Sydney, Australia

Evolution and Ecology Research Center

Sydney, Australia
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Dominguez-Tejo E.,University of New South Wales | Metternicht G.,University of New South Wales | Johnston E.,Evolution and Ecology Research Center | Johnston E.,Sydney Institute of Marine Science | And 2 more authors.
Marine Policy | Year: 2016

Planning a sustainable future for coastal populations requires the effective implementation of ecosystem management frameworks that explicitly incorporate human activities. A coupled framework of the Ecosystem-Based Approach with Marine Spatial Planning has been discussed and promoted by coastal managers for more than a decade. The proposed framework supports a balanced approach between development needs and the natural environment. This paper presents a qualitative review of Marine Spatial Planning case studies to gain insights into methodological approaches that account for human systems as components of the coastal environment. A total of twelve Marine Spatial Planning case studies were evaluated. Their use and integration of the Ecosystem-Based framework was assessed through a linguistic scale linked to a score of fuzzy numbers. Two management issues of interest were highlighted: how social, economic and environmental values were integrated into the spatial planning analysis; and how cross-realm connectivity was addressed by planning teams. Although the majority of case studies claimed to use the Ecosystem-Based Approach as the guiding framework, mixed results were observed. Relevant features of the Ecosystem-Based Approach were rarely included; such as the standardization of pressures from human activities, the integration of frameworks to assess ecosystem services and the implementation of Precautionary and Adaptive Management approaches. Important knowledge gaps were observed with regards to the assessment of social values, including the lack of spatial representation of ‘social connections’ to the marine environment and the lack of economic estimates of non-market values. Terrestrial and catchment units were not included in the majority of case studies; however, water quality management was used as a key element for the consideration of transboundary impacts. This comparative study reveals major differences in how coastal managers understand and integrate Ecosystem-Based Approaches with Marine Spatial Planning. © 2016 Elsevier Ltd

Forster M.A.,Edaphic Scientific Pty Ltd | Forster M.A.,University of Queensland | Dalrymple R.L.,Evolution and Ecology Research Center | Bonser S.P.,Evolution and Ecology Research Center
Trees - Structure and Function | Year: 2016

Key message: TheAcaciaphyllode leaf form is hypothesised to be an adaptation to drought. However, in this experiment, the timing of phyllode development was not related to a low water treatment.Abstract: Acacia species have markedly different leaf forms known as compound leaves, transitional leaves, and phyllodes, also known as heteroblastic development. The different leaf types are thought to confer an advantage under varying moisture regimes, with phyllodes favoured in drier conditions. The hypothesis that phyllodes develop earlier under low water treatment was tested in this experiment. Three watering level treatments (100, 50, and 25 %) were imposed on seedlings of A. implexa to assess developmental traits (leaf emergence, initial onset of transitional leaves, and phyllodes), biomass allocation patterns (root, stem, compound leaf area/mass, transitional leaf area/mass, and phyllode area/mass), and leaf anatomy traits (epidermis, palisade and spongy mesophyll, and stomatal density). Across watering treatments, there was no difference in the developmental onset of transitional leaves or phyllodes (produced at the 6th and 9th nodes, respectively). Under low watering treatment, there was a decrease in stem height per unit stem diameter, shorter internodes, and greater allocation of biomass to roots. There was no significant difference in leaf anatomy traits. Under the low watering treatment, there was less compound leaf area and mass due to leaf shedding. In this experiment, the low watering treatment did not favour phyllode development at the expense of compound leaf development. Rather, it was found that A. implexa responds to a low water treatment similarly to many other plant species: increased allocation to roots, increased stem area per unit stem height, decrease in leaf area through senescence of older leaves, and lower relative growth rates. © 2016 Springer-Verlag Berlin Heidelberg

Borchard N.,University of Bonn | Borchard N.,Jülich Research Center | Siemens J.,University of Bonn | Ladd B.,University of Bonn | And 5 more authors.
Soil and Tillage Research | Year: 2014

Adding biochar to tropical soils is a strategy for improving crop yield and mitigating climate change, but how various biochar types affect crop yield and the properties of temperate soils is still in dispute. Here, we evaluated how slow-pyrolysis charcoal and two biochars derived from energy production (gasification coke and flash-pyrolysis char) affected the growth of Zea mays L. and the related properties of sandy and silty soils within a 3-year mesocosm experiment. Fertilization was performed to optimize plant growth as would be done under common agricultural practice. Analyses included the monitoring of yield, plant and soil nutrients, aggregate stability, cation exchange and water holding capacity, and black carbon content. The results showed that the added biochars did not affect crop yield at an application rate of 15gbiocharkg-1 of soil. Increasing the application rate of slow-pyrolysis charcoal to 100gkg-1 resulted in decreased plant biomass in the second and third year of the experiment, likely as a result of nutrient imbalances and N-immobilization. We did not detect any degradation of the added black carbon; however, beneficial effects on plants were limited by the small and transient effect of these biochars on the physical and chemical properties of soil. Overall, our results indicate that the added carbon from biochars is stored in soil, but all treatments tested failed to improve plant yield for the studied temperate soils under the given application rates and common agricultural practice. © 2014 Elsevier B.V.

Edwards W.,James Cook University | Moles A.T.,Evolution and Ecology Research Center | Chong C.,James Cook University | Chong C.,Australian National University
PLoS ONE | Year: 2015

Among co-occurring species, values for functionally important plant traits span orders of magnitude, are uni-modal, and generally positively skewed. Such data are usually logtransformed "for normality" but no convincing mechanistic explanation for a log-normal expectation exists. Here we propose a hypothesis for the distribution of seed masses based on generalised extreme value distributions (GEVs), a class of probability distributions used in climatology to characterise the impact of event magnitudes and frequencies; events that impose strong directional selection on biological traits. In tests involving datasets from 34 locations across the globe, GEVs described log10 seed mass distributions as well or better than conventional normalising statistics in 79% of cases, and revealed a systematic tendency for an overabundance of small seed sizes associated with low latitudes. GEVs characterise disturbance events experienced in a location to which individual species' life histories could respond, providing a natural, biological explanation for trait expression that is lacking from all previous hypotheses attempting to describe trait distributions in multispecies assemblages. We suggest that GEVs could provide a mechanistic explanation for plant trait distributions and potentially link biology and climatology under a single paradigm. © 2015 Edwards et al.

Letten A.D.,Center for Ecosystem Science | Cornwell W.K.,Evolution and Ecology Research Center
Methods in Ecology and Evolution | Year: 2015

An increasingly popular practice in community ecology is to use the evolutionary distance among interacting species as a proxy for their overall functional similarity. At the core of this approach is the implicit, yet poorly recognized, assumption that trait dissimilarity increases linearly with divergence time, that is all evolutionary time is considered equal. However, given a classic Brownian model of trait evolution, we show that the expected functional displacement of any two taxa is more appropriately represented as a linear function of time's square root. In light of this mismatch between theory and methodology, we argue that current methods at the interface of ecology and evolutionary biology often greatly overweight deep time relative to recent time. An easy solution to this weighting problem is a square root transformation of the phylogenetic distance matrix. Using simulated models of trait evolution and community assembly, we show that this transformation yields considerably higher statistical power, with improvements in 92% of trials. This methodological update is likely to improve our understanding of the connection between evolutionary relatedness and contemporary ecological processes. © 2014 British Ecological Society.

Wan J.S.H.,Evolution and Ecology Research Center | Fazlioglu F.,Evolution and Ecology Research Center | Bonser S.P.,Evolution and Ecology Research Center
Plant Ecology and Diversity | Year: 2016

Background: Species undergoing range expansion adapt to novel and stressful environments at range fronts. These adaptations of the edge populations may incur fitness costs. These costs may play a crucial role in stopping range expansion before absolute physiological and evolutionary limits were reached. Costs however have proven to be elusive. These may be specifically expressed under competition. Aims: Here, we assessed the costs of adaptation in range-edge populations of an invasive plant by evaluating plant responses under competition. Methods: We grew plants from range-centre and edge populations under competition treatments in a glasshouse. We predicted that plants from the range-edge would express lower reproductive efficiency under competition compared with centre population plants, and this would indicate a potentially maladaptive response. Results: Under high competition, plants from the range-edge expressed lower reproductive efficiency relative to range-centre plants which supported our prediction. In addition, they were more heavily affected by competition. Conclusions: Adaptation to novel environments at the range-edge has incurred a cost as a potentially maladaptive response under competition, which may contribute to the formation of the range-edge. This finding suggests that these costs likely form part of the classic trade-offs involved with stress-tolerance and may have effects on range evolution. © 2016 Botanical Society of Scotland and Taylor & Francis

Fazlioglu F.,Evolution and Ecology Research Center | Al-Namazi A.,Evolution and Ecology Research Center | Bonser S.P.,Evolution and Ecology Research Center
Ecology and Evolution | Year: 2016

Plant strategy and life-history theories make different predictions about reproductive efficiency under competition. While strategy theory suggests under intense competition iteroparous perennial plants delay reproduction and semelparous annuals reproduce quickly, life-history theory predicts both annual and perennial plants increase resource allocation to reproduction under intense competition. We tested (1) how simulated competition influences reproductive efficiency and competitive ability (CA) of different plant life histories and growth forms; (2) whether life history or growth form is associated with CA; (3) whether shade avoidance plasticity is connected to reproductive efficiency under simulated competition. We examined plastic responses of 11 herbaceous species representing different life histories and growth forms to simulated competition (spectral shade). We found that both annual and perennial plants invested more to reproduction under simulated competition in accordance with life-history theory predictions. There was no significant difference between competitive abilities of different life histories, but across growth forms, erect species expressed greater CA (in terms of leaf number) than other growth forms. We also found that shade avoidance plasticity can increase the reproductive efficiency by capitalizing on the early life resource acquisition and conversion of these resources into reproduction. Therefore, we suggest that a reassessment of the interpretation of shade avoidance plasticity is necessary by revealing its role in reproduction, not only in competition of plants. © 2016 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Schwanz L.E.,Australian National University | Schwanz L.E.,Evolution and Ecology Research Center
Journal of Experimental Biology | Year: 2016

The environment experienced by parents can impact the phenotype of their offspring (parental effects), a critical component of organismal ecology and evolution in variable or changing environments. Although temperature is acentral feature of the environment forectotherms, its role in parental effects has been little explored until recently. Here, parental basking opportunity was manipulated in an oviparous lizard with temperature-dependent sex determination, the jacky dragon (Amphibolurus muricatus). Eggs were incubated at a temperature that typically produces a 50:50 sex ratio, and hatchlings were reared in a standard thermal environment. Offspring of parents in short bask conditions appeared to have better fitness outcomes in captive conditions than those of parents in long bask conditions - they had greater growth and survival as a function of their mass. In addition, the sex of offspring (male or female) depended on the interaction between parental treatment and egg mass, and treatment impacted whether sons or daughters grew larger in their first season. The interactive effects of treatment on offspring sex and growth are consistent with adaptive explanations for the existence of temperature-dependent sex determination in this species. Moreover, the greater performance recorded in short bask offspring may represent an anticipatory parental effect to aid offspring in predicted conditions of restricted thermal opportunity. Together, these responses constitute a crucial component of the population response to spatial or temporal variation in temperature. © 2016. Published by The Company of Biologists Ltd.

Fazlioglu F.,Evolution and Ecology Research Center | Wan J.S.H.,Evolution and Ecology Research Center | Bonser S.P.,Evolution and Ecology Research Center
Austral Ecology | Year: 2016

Specialization can allow plants to perform well in their home environments at the expense of poor performance in other habitats. A great difference in performance across habitats is observed as high phenotypic plasticity in performance traits and a by-product of selection. However, phenotypic plasticity (particularly adaptive plasticity) can be an active response to the selection by allowing the maintenance of performance. Therefore, specialization and adaptive plasticity delineate two opposing strategies. The specialization hypothesis presents a non-adaptive interpretation of plasticity and predicts that phenotypic plasticity of performance traits is greater in specialization to good habitats, whereas bad habitat specialists express low plasticity in performance traits. We tested the specialization hypothesis using plants adapted to extremely stressful mine-site habitats (sites with highly acidic soil and heavy metal contamination). Seeds of five herbaceous species were collected from high stress (mine site) and low stress habitats. We established a glasshouse experiment where seedlings from high and low stress habitats were grown under near neutral pH and acid soil treatments. We compared performance trait plasticity (e.g. biomass) from high stress and low stress populations and found that there was no significant difference in performance traits between high and low stress populations across treatments. The overall result did not support the specialization hypothesis. Moreover, our results suggest that the species invaded the mine sites are either extreme generalists or the surrounding populations retain some stress tolerant genotypes that are capable of invading the mine sites. © 2016 Ecological Society of Australia.

Wan J.S.H.,Evolution and Ecology Research Center | Bonser S.P.,Evolution and Ecology Research Center
Journal of Plant Ecology | Year: 2016

Aims We test the hypothesis that invasive plant species at their range edges experience lower herbivory and allocate less to defense at the edge of an expanding range edge than from more central parts of their distribution, during secondary invasion in a new range. Invasive plants are often able to spread rapidly through new areas. The success of invasive species in new ranges is frequently attributed to enemy release in these new areas and associated evolutionary changes minimizing allocation to defense in favor of growth and reproduction. Enemy release could also explain rapid advances of invasive species upon arriving in new habitats. If invasive species accumulate enemies over time in a new location, then these species may experience a release from their enemies at expanding range fronts. Enemy release at these range fronts may accelerate range expansion. Methods We used populations of four woody invasive species within the invaded range, and four native control species. We quantified leaf herbivory and leaf physical defense traits at both range central and range edge locations, over two 1-month sampling periods, sampled 7 months apart. Important Findings Herbivory at the range edge did not differ to the range center but patterns were not consistent across species. There was a trend for lower herbivory at the range edge for Lantana camara, which was reflected in lower leaf toughness. Overall, leaf toughness was greater at the range edge location across invasive and control species. Physical defenses were different among range locations in a few species, though most species show the same trend, suggesting higher herbivory pressures at the range edge location or differences may be due to climatic factors. Leaves of L. camara were significantly less tough at range edges, suggesting that some species can potentially escape their enemies at range edges. However, our results overall do not support the hypothesis that plants at the edge of their ranges experience reduced impact from their enemies. © 2016 The Author 2016.

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