Native vegetation of coastal floodplains ? a diagnosis of the major plant communities in New South Wales

2005 ◽  
Vol 11 (2) ◽  
pp. 81 ◽  
Author(s):  
David A. Keith ◽  
Judith Scott
Keyword(s):  
Plant Communities ◽  
Vascular Plant ◽  
Mixed Forest ◽  
Distribution Patterns ◽  
Spatial Arrangement ◽  
Ecological Communities ◽  
Weed Invasion ◽  
Eucalypt Forest ◽  
Acid Sulphate Soils ◽  
Hunter Region

Coastal floodplains are among the most modified landscapes in southeastern Australia. We used available vegetation survey data for coastal alluvium and other unconsolidated Quarternary sediments to construct a diagnosis of the major plant communities and document their flora. We used soil landscape maps and historical portion plans to gain an understanding of the distribution and environmental relationships of the communities. The flora of coastal floodplains includes more than 1 000 native vascular plant taxa and more than 200 introduced taxa. The introduced flora is likely to be considerably larger, given that sampling was biased toward the least disturbed sites. Six major plant communities were diagnosed including a rainforest found north from the Shoalhaven floodplain, a mixed forest of eucalypts and melaleucas found north from Jervis Bay, a casuarina forest (sometimes with melaleuca) found throughout the coast, one open eucalypt forest found principally south from the Hunter region, another open eucalypt forest found north of the Hunter region and a complex of treeless wetland assemblages scattered throughout the coast. The extent and spatial arrangement of these communities varies between floodplains, with landform, rainfall, water regime and soil properties including moisture, fertility and salinity thought to be important factors mediating their distribution patterns. All six assemblages are listed as Endangered Ecological Communities under Threatened Species legislation. The coastal floodplain communities continue to be threatened by land clearing and crop conversion, fragmentation, changes to water flows, flooding and drainage, input of polluted runoff, weed invasion, activation of acid sulphate soils, climate change and degradation through rubbish dumping and other physical disturbances.

A Floristic Comparison of Vascular Species in Tasmanian Oldgrowth Mixed Forest With Regeneration Resulting From Logging and Wildfire

1994 ◽  
Vol 42 (4) ◽  
pp. 383 ◽  
Author(s):  
JE Hickey
Keyword(s):  
Life Span ◽  
Vascular Plant ◽  
Mixed Forest ◽  
Critical Factor ◽  
Eucalypt Forest ◽  
Disturbed Areas ◽  
Fern Species ◽  
Eucalypt Forests ◽  
Or Fires ◽  
Epiphytic Fern

About 20% of Tasmania's wet eucalypt forest is mixed forest, i.e. having a rainforest understorey and a eucalypt overstorey. While one-third of the mixed forest is formally reserved, much of the remainder is subject to logging on an 80-100 year rotation which is insufficient for the redevelopment of mature mixed forest. The routine silvicultural regeneration treatment for wet eucalypt forests is to clearfell, burn and sow with eucalypt seed. A comparison of the Vascular floristics of 20-30-year-old silvicultural and wildfire regeneration with oldgrowth mixed forest showed that most species common in oldgrowth mixed forest were represented in approximately similar frequencies in silvicultural regeneration and wildfire regeneration. The major floristic difference between the two regeneration types was the much lower frequency of oldgrowth epiphytic fern species in silvicultural regeneration and a higher frequency of a sedge species often associated with disturbed areas. However, after a single logging treatment, the vascular plant floristics of silvicultural regeneration were sufficiently similar to wildfire regeneration to assume that, in the absence of further logging or fires, the silvicultural regeneration could become mature mixed forest and eventually rainforest. Further work is required to determine whether regrowth mixed forest can be logged at 80-100 years and still retain sufficient rainforest elements to eventually return to mixed forest within the life span of the dominant eucalypts. The critical factor in the silvicultural perpetuation of mixed forest may be rotation length rather than regeneration treatment.

scholarly journals Different temporal trends in vascular plant and bryophytes communities along elevational gradients over four decades of warming

2020 ◽  
Author(s):  
Antoine Becker-Scarpitta ◽  
Diane Auberson-Lavoie ◽  
Mark Vellend
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Environmental Changes ◽  
Vascular Plant ◽  
Elevation Gradient ◽  
Temporal Trends ◽  
Community Change ◽  
Ecosystem Functions ◽  
Ecological Communities

Abstract1: Despite many studies showing biodiversity responses to warming, the generality of such responses across taxa remains unclear. Very few studies have tested for evidence of bryophyte community responses to warming, despite the fact that bryophytes are major contributors to diversity in many ecosystems, playing a central role in ecosystem functions. Understanding variation among taxa in their responses to warming is crucial for identifying priorities in conservation.2: We report an empirical study comparing long-term change of bryophyte and vascular plant communities in two sites with contrasting long-term warming trends. To assess long-term responses of ecological communities to warming, we used “legacy” botanical records as a baseline for comparison with contemporary resurveys.We hypothesized that ecological changes would be greater in sites with a stronger warming trends, and that vascular plant communities would be more sensitive than bryophyte communities to climate warming. For each taxon in each site, we quantified the magnitude of changes in species’ distributions along the elevation gradient, species richness, and community composition.3: Temporal changes in vascular plant communities were consistent with the warming hypothesis, but this was not the case for bryophytes. We also did not find clear support for the hypothesis that vascular plants would show greater sensitivity than bryophytes to warming, with results depending on the metric of community change. As predicted for sites with a strong warming trend, we found a significant upward shift in the distributions of vascular plants but not bryophytes.Synthesis: Our results are in accordance with recent literature showing that local diversity can remain unchanged despite strong changes in composition. Regardless of whether one taxon is systematically more or less sensitive to environmental change than another, our results suggest that vascular plants cannot be used as a surrogate for bryophytes in terms of predicting the nature and magnitude of responses to warming. In sites that experienced the same environmental changes, we found that communities of bryophytes and vascular plants did not predictably change in the same ways. Thus, to assess overall biodiversity responses to global change, data from different taxonomical groups and community properties need to be synthesized.

scholarly journals Are Distribution Patterns Correlated with Plant Traits?

2021 ◽  
Author(s):  
◽  
Benjamin Magana-Rodriguez
Keyword(s):  
Life History ◽  
Leaf Area ◽  
Spatial Patterns ◽  
Life History Traits ◽  
Multiple Scales ◽  
Spatial Scales ◽  
Regional Scale ◽  
Distribution Patterns ◽  
Spatial Arrangement ◽  
Scaling Relationship

<p>The current crisis in loss of biodiversity requires rapid action. Knowledge of species' distribution patterns across scales is of high importance in determining their current status. However, species display many different distribution patterns on multiple scales. A positive relationship between regional (broad-scale) distribution and local abundance (fine-scale) of species is almost a constant pattern in macroecology. Nevertheless interspecific relationships typically contain much scatter. For example, species that possess high local abundance and narrow ranges, or species that are widespread, but locally rare. One way to describe these spatial features of distribution patterns is by analysing the scaling properties of occupancy (e.g., aggregation) in combination with knowledge of the processes that are generating the specific spatial pattern (e.g., reproduction, dispersal, and colonisation). The main goal of my research was to investigate if distribution patterns correlate with plant life-history traits across multiple scales. First, I compared the performance of five empirical models for their ability to describe the scaling relationship of occupancy in two datasets from Molesworth Station, New Zealand. Secondly, I analysed the association between spatial patterns and life history traits at two spatial scales in an assemblage of 46 grassland species in Molesworth Station. The spatial arrangement was quantified using the parameter k from the Negative Binomial Distribution (NBD). Finally, I investigated the same association between spatial patterns and life-history traits across local, regional and national scales, focusing in one of the most diverse families of plant species in New Zealand, the Veronica sect. Hebe (Plantaginaceae). The spatial arrangement was investigated using the mass fractal dimension. Cross-species correlations and phylogenetically independent contrasts were used to investigate the relationships between plant life-history traits and spatial patterns on both data bases. There was no superior occupancy-area model overall for describing the scaling relationship, however the results showed that a variety of occupancy-area models can be fit to different data sets at diverse spatial scales using nonlinear regression. Additionally, here I showed that it is possible to deduce and extrapolate information on occupancy at fine scales from coarse-scale data. For the 46 plantassemblage in Molesworth Station, Specific leaf area (SLA) exhibits a positive association with aggregation in cross-species analysis, while leaf area showed a negative association, and dispersule mass a positive correlation with degree of aggregation in phylogenetic contrast analysis at a local-scale (20 × 20 m resolution). Plant height was the only life-history trait that was associated with degree of aggregation at a regional-scale (100 × 60 mresolution). For the Veronica sect. Hebe dataset, leaf area showed a positive correlation with aggregation while specific leaf area showed a negative correlation with aggregation at a fine local-scale (2.5-60 m resolution). Inflorescence length, breeding system and leaf area showed a negative correlation with degree of aggregation at a regional-scale (2.5-20 km resolution). Height was positively associated with aggregation at national-scale (20-100 km resolution). Although life-history traits showed low predictive ability in explaining aggregation throughout this thesis, there was a general pattern about which processes and traits were important at different scales. At local scales traits related to dispersal and completion such as SLA , leaf area, dispersule mass and the presence of structures in seeds for dispersal, were important; while at regional scales traits related to reproduction such as breeding system, inflorescence length and traits related to dispersal (seed mass) were significant. At national scales only plant height was important in predicting aggregation. Here, it was illustrated how the parameters of these scaling models capture an important aspect of spatial pattern that can be related to other macroecological relationships and the life-history traits of species. This study shows that when several scales of analysis are considered, we can improve our understanding about the factors that are related to species' distribution patterns.</p>

Takhtajan's floristic regions and foliicolous lichen biogeography: a compatibility analysis

2003 ◽  
Vol 35 (1) ◽  
pp. 33-53 ◽  
Author(s):  
Robert Lücking
Keyword(s):  
Large Scale ◽  
New Caledonia ◽  
Vascular Plant ◽  
Distribution Patterns ◽  
Plant Distribution ◽  
Sufficient Information ◽  
East African ◽  
Foliicolous Lichens ◽  
North East ◽  
Compatibility Analysis

AbstractTakhtajan's floristic regions of the world, based on vascular plant distribution, were used for a comparative analysis of foliicolous lichen biogeography. Of the 35 regions distinguished by that author, 23 feature foliicolous lichens. The South-East African, Fijian, Polynesian and Hawaiian regions lack sufficient information and were excluded from further analysis. Using multi-dimensional scaling and cluster and cladistic analyses, the remaining 19 regions were grouped into six lichenogeographical regions: (1) Neotropics, (2) African Paleotropics (including Madagascar, Réunion and Seychelles), (3) Eastern Paleotropics (including North-East Australia and New Caledonia), (4) Valdivian region (temperate rainforest in southern South America), (5) Tethyan region (subtropical areas of Macaronesia, Mediterranean, and Western Irano-Turanian) and (6) Neozealandic-Tasmanian region (temperate rainforests of New Zealand and Tasmania). Affinities between these six large scale regions, with 57–77% shared species, are still stronger than those between the 35 smaller scale regions denned by Takhtajan [(20−)40–60(−75)% shared species]. Based on presence/absence within each of the six regions, 22 potential distribution patterns were defined for foliicolous lichens. Many species are widely distributed; 21% are cosmopolitan or pantropical, while 19% are disjunct on at least two continents, and only 60% are restricted to one of the three major tropical areas (nearly 100% in vascular plants). Most of the latter are found in the Neotropics, while the African Paleotropics are poor in endemics. Most genera deviate significantly from overall distribution patterns; for example, Strigula and Calopadia have higher proportions of widely distributed species, while Porina displays a concentration of Eastern Paleotropical endemics. Species diversity and composition of the six regions indicate that the three extra-tropical foliicolous lichen biotas (Valdivian, Tethyan, Neozealandic-Tasmanian) are the result of partly separate evolutionary histories. On the other hand, there is a strong affinity between the Neotropics and the African Paleotropics, suggesting a shared Western Gondwanan element in the foliicolous lichen biotas of these two regions.

Species Richness of Sclerophyll (Heathy) Plant Communities in Australia ̵2 the Influence of Overstorey Cover

1989 ◽  
Vol 37 (4) ◽  
pp. 337 ◽  
Author(s):  
RL Specht ◽  
A Specht
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Communities ◽  
Unit Area ◽  
Vascular Plant ◽  
Biotic Factor ◽  
Rate Of Development ◽  
South West ◽  
Open Forest ◽  
Simultaneous Decrease

The species richness (number of vascular-plant species per unit area) of sclerophyll (heathy) plant communities is examined from south-east Queensland to south-west Western Australia. The species richness of communities of heathy open forest, heathy open scrub, dry heathland and wet heathland is consist- ently similar throughout southern Australia and decreases from dry heathland (on laterite, coastal and inland localities) to heathy open forest, heathy open scrub and wet heathland. Investigation of related microcommunities at Cooloola, Stradbroke Island, Ku-ring-gai Chase and Wilsons Promontory indicates that species richness decreases linearly as overstorey cover increases. In post-fire succession on Stradbroke Island heathy woodland and Dark Island heathland, species richness declines linearly as overstorey cover increases during the regeneration of the community. The appli- cation of limiting fertiliser to Stradbroke Island heathy woodland and Dark Island heathland increases the rate of development of overstorey cover, with a simultaneous decrease in species richness. Species richness of the understorey strata of plant communities appears to be inversely related to the rate of development of foliage projective cover in the overstorey. If an environmental or biotic factor inhibits or retards the development of overstorey cover, the understorey increases in species richness. Conversely, if any environmental or biotic factor accelerates the development of overstorey cover, the understorey species show a reduction in species richness.

Soil CO2 efflux and root respiration at three sites in a mixed pine and spruce forest: seasonal and diurnal variation

2001 ◽  
Vol 31 (5) ◽  
pp. 786-796 ◽  
Author(s):  
Britta Widén ◽  
Hooshang Majdi
Keyword(s):  
Diurnal Variation ◽  
Temperature Sensitivity ◽  
Root Respiration ◽  
Fine Root ◽  
Mixed Forest ◽  
Distribution Patterns ◽  
Co2 Efflux ◽  
Root Temperature ◽  
Coarse Root ◽  
N Concentration

Soil CO2 efflux and respiration of excised roots were measured with a LI-COR 6200 at three sites in a mixed forest (60°05'N, 17°3'E), from May to October 1999, both day and night. Fine-root (<5 mm in diameter) respiration was measured at ambient root temperature and soil CO2 partial pressure, and the roots were analysed for nitrogen (N) concentration. Root-density data obtained from soil cores were used to estimate fine-root biomass. Coarse-root respiration was estimated using stand data, literature data, and allometric relationships. Soil CO2 efflux, 3.0–7.0 µmol·m–2·s–1, differed between sites but showed no diurnal variation. Maximum values were obtained in July through August. Fine-root respiration, 0.3–4.7 nmol·g–1·s–1, decreased after peaking in early July and showed no diurnal variation. The seasonal mean was lowest at the South site, where also root distribution patterns were different and root N concentrations were lower. Fine-root respiration increased with root N concentration; however, the relationship was very weak, since the variation in root N concentration between sites and times of year was small. Both soil CO2 efflux and fine-root respiration increased exponentially with soil and root temperature, respectively, although fine-root respiration was twice as sensitive. The percentage of soil CO2 efflux emanating from roots was 33–62% in May, thereafter decreasing to 12–16% in October. This, in combination with larger temperature sensitivity for fine-root respiration, is suggested to cause the temperature sensitivity of soil CO2 efflux to diminish over the season.

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