Fire, Buried Germinable Seed Banks and Grass Species Establishment in an Urban Eucalypt Forest Reserve

1996 ◽  
Vol 44 (4) ◽  
pp. 413 ◽  
Author(s):  
BM Odgers
Keyword(s):  
Seed Banks ◽  
Grass Species ◽  
Similar Species ◽  
Forest Reserve ◽  
Eucalypt Forest ◽  
Open Forest ◽  
Forest Sites ◽  
Before And After ◽  
Species Establishment ◽  
Germinable Seed

The buried germinable seed banks of two natural contrasting savanna open-forest sites were investigated before and after a wildfire. It was found that while the number of buried germinable grass and sedge seeds remained the same, the number of buried germinable dicotyledon seeds in both sites increased after the fire. It was also found that there were similar species of grasses present in the buried germinable seed banks before and after the fire. When germinating grass seedlings in the burnt and unburnt sites were compared, similar species of grasses were found in the germinating seedlings at both sites; however, more grass seedlings germinated in the burnt site than in the unburnt site.

Seasonal Variation in Buried Germinable Seed Banks of Grass Species in an Urban Eucalypt Forest Reserve

1999 ◽  
Vol 47 (4) ◽  
pp. 623 ◽  
Author(s):  
B. M. Odgers
Keyword(s):  
Seasonal Variation ◽  
Seed Banks ◽  
Grass Species ◽  
Seasonal Patterns ◽  
Forest Reserve ◽  
Native Grass ◽  
Eucalypt Forest ◽  
Disturbed Forest ◽  
Exotic Grass ◽  
Germinable Seed

Grass species in the buried germinable seed banks of selected forest, mown and road-bank sites in the Mt Coot-tha Reserve, south-eastern Queensland were quantified for five consecutive seasons to determine seasonal patterns in the seed banks, and differences in seasonal patterns between native and exotic grass species, and between grasses in natural and disturbed forest areas. Ten types of seed banks were identified. While native and exotic species had similar seed banks most native grass species had transient seed banks whereas most exotic grass species had persistent seed banks.

Seed Banks and Vegetation of Three Contrasting Sites in an Urban Eucalypt Forest Reserve

1994 ◽  
Vol 42 (4) ◽  
pp. 371 ◽  
Author(s):  
BM Odgers
Keyword(s):  
Seed Bank ◽  
Native Species ◽  
Seed Banks ◽  
Species Density ◽  
Grass Species ◽  
Forest Site ◽  
The Road ◽  
Eucalypt Forest ◽  
Exotic Grass ◽  
Germinable Seed

Grass species, sedges and dicotyledons in the vegetation and the buried germinable seed of a natural subtropical eucalypt forest, a mown and a road bank site were identified in four consecutive seasons and the data pooled to give a more precise assessment of taxa present each year. Differences in the relative proportions of taxa, differences in species density, origin and life history of grass species in the seed bank and vegetation, as well as differences in biomass and rate of germination of buried germinable grass seed, in the three sites were investigated. In all three sites, grasses were the dominant taxa of the ground stratum of the vegetation with each site having its own group of mainly perennial grasses. The seed banks were dominated by grasses in the forest site, sedges in the mown site and dicotyledons in the road bank site. There were significant differences in species density of grasses in both the vegetation and buried germinable seed between sites, with the forest site having a significantly lower species density in its seed bank than the mown and road bank sites, and the vegetation of the forest and mown sites having a lower species density than the road bank site. However, there was a high correlation between the grass species of the vegetation and the buried germinable seed in each of the three sites - the species which dominated the vegetation also dominated the biomass of buried germinable seed in each site. The mown and road bank sites had larger numbers and biomass of buried germinable grass seed than the natural forest site. There were no differences in the number of days to first germination and the number of days to 50% germination of the buried germinable seed between any of the sites. Exotic grass species were present in the seed banks of the forest, mown and road bank sites. Exotics were prevalent in the vegetation of the mown and road bank sites but not evident in the vegetation of the forest site. Exotic species with higher buried germinable seed numbers and similar germination rates to the native species are likely to have a competitive advantage over the native species. It appears that the mown and road bank sites, may act as reservoirs for the more competitive exotic grass species, enabling them to invade the seed banks of the forest areas.

Contrasting Diaspore and Vegetation Attributes of Grasses From Natural and Disturbed Habitats in an Urban Eucalypt Forest Reserve

1993 ◽  
Vol 41 (6) ◽  
pp. 637 ◽  
Author(s):  
BM Odgers ◽  
RW Rogers
Keyword(s):  
Grass Species ◽  
Forest Species ◽  
Forest Reserve ◽  
Morphological Attributes ◽  
The Road ◽  
Eucalypt Forest ◽  
Disturbed Areas ◽  
Undisturbed Forest ◽  
Mowing Regime ◽  
Disturbed Habitats

Forty one species of grasses from a eucalypt forest reserve near Brisbane, Australia, were allocated to groups characteristic of undisturbed forest, regularly mown areas, and road banks. Morphological attributes of diaspores, height and growth habit of mature plants, species origin, flowering times and life history were determined for each species. Species characteristic of the mown areas had lighter diaspores than the forest gasses and did not possess awns; if a callus was present it was blunt and did not have antrorse hairs. Species from mown areas also differed from the forest species in being mainly short stoloniferous exotics which flowered for longer than the forest species. Species characteristic of the natural forest and road bank areas had diaspores of similar mass, similar diaspores attributes (awns, callus and antrorse hairs) and species of both habitats were mainly tall and tufted. The road bank species differed from the forest species in being mainly of exotic origin and in flowering for up to 9 months per year longer than the forest species. That grass species of mown areas successfully compete with forest species in mown areas may be because of a mowing regime which selects for short, mainly stoloniferous, species which have longer periods of diaspore production than the forest species. As road banks are not subjected to regular mowing, an extended pattern of flowering which ensures a continuous supply of diaspores may account for road bank species successfully competing with forest species in disturbed areas.

scholarly journals A study of soil seed banks across one complete chronosequence of secondary succession in a karst landscape

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10226
Author(s):  
Xiaole He ◽  
Li Yuan ◽  
Zhen Hong Wang ◽  
Zizong Zhou ◽  
Li Wan
Keyword(s):  
Species Richness ◽  
Seed Germination ◽  
Secondary Succession ◽  
Life Forms ◽  
Seed Banks ◽  
Similar Species ◽  
Seed Density ◽  
Rocky Desertification ◽  
Karst Landscape ◽  
Before And After

Anthropogenic disturbance and distinctive geochemistry have resulted in rocky desertification in many karst regions of the world. Seed banks are crucial to vegetation regeneration in degraded karst ecosystems characterized by a discontinuous distribution of soil and seasonal drought stress. However, the dynamics of seed banks across one complete series of secondary succession and the underlying mechanisms remain unclear. We selected eight typical stages during secondary succession, conducted aboveground vegetation survey and collected 960 soil samples in the Guiyang karst landscape of China. Seed density, species richness and plant life forms in seed banks were determined via the germination method. The results indicated that the seed density in seed banks before and after field seed germination was significantly different among most succession stages. Community succession had impacts on the seed density of seed banks before and after field seed germination. Seed density ranged from 1,042 seedlings.m−2 in evergreen broadleaf forests to 3,755 seedlings.m−2 in the herb community, which was a relatively high density. The seed density and similar species composition between the seed banks and vegetation declined with succession from early to later stages. Species richness in seed banks was highest in middle succession stages and increased with increasing species richness of aboveground vegetation. The species richness of the five life forms in the seed banks showed different variations across these succession stages. The conservation of diverse aboveground vegetation can maintain the diversity of seed banks for restoration.

The germinable soil seedbank of Eucalyptus victrix grassy woodlands at Roy Hill station, Pilbara district, Western Australia

2004 ◽  
Vol 26 (1) ◽  
pp. 17 ◽  
Author(s):  
R. A. Graham ◽  
S. K. Florentine ◽  
J. E. D. Fox ◽  
T. M. Luong
Keyword(s):  
Species Composition ◽  
Western Australia ◽  
Perennial Grass ◽  
Summer Rainfall ◽  
Distribution Patterns ◽  
Grass Species ◽  
Surface Areas ◽  
Hill Station ◽  
Soil Seedbank ◽  
Germinable Seed

The paper reports soil seedbank species composition, of Eucalyptus victrix grassy woodlands, of the upper Fortescue River in the Pilbara District, Western Australia. In this study, our objectives were to investigate germinable soil seedbanks and species composition in response to three simulated seasons, using emergence. Variation in seed density from three depths was tested. Four field sites were sampled. Thirty samples were collected in late spring, after seed rain and before summer rainfall. From each sample spot, three soil depths (surface, 1–5, and 6–10 cm) were segregated from beneath surface areas of 100 cm2. Samples were later incubated in a glasshouse to simulate three different seasonal conditions (autumn, winter and spring). Germinating seedlings were recorded on emergence and grown until identified. Forty-one species germinated, comprising 11 grasses (7 annuals and 4 perennials), 25 annual herbs and 5 perennial herbs. Distribution patterns of germinable seed in both the important annual grass Eragrostis japonica and the perennial Eragrostis setifolia (a preferred cattle fodder species), suggest that seedbank accumulation differs among species and between sites. In part, this may be associated with the absence of grazing. Species with most total germinable seed were E. japonica (Poaceae; 603/m2), and the annual herbs Calotis multicaulis (Asteraceae; 346/m2), and Mimulus gracilis (Scrophulariaceae; 168/m2). Perennial grass seed was sparse. Spring simulation gave most germination (1059), followed by autumn (892) and winter (376) sets. Greatest species diversity was produced from the spring simulation (33 species), followed by autumn (26), and winter (22). Of the total germination, 92% came from 17 species that were represented in all three simulations. Of the 1227 grass seedlings counted, most were recruited from the surface soil (735), followed by the 5 (310) and 10 (182) cm depths. Marginally more grass seedlings germinated from the spring simulation (558) than the autumn set (523). Only 11.9% of grass germinants came from the winter simulation. All grass species recruited from the soil seedbanks had a C4 photosynthetic pathway. Except for Cenchrus ciliaris all grass species are native to Australia. Of the four sites sampled, one fenced to exclude cattle five years earlier had significantly more germination than the three unfenced sites. Seedbank sampling produced several new records for plants in the areas sampled.

scholarly journals Factors influencing early restoration progress of a Eucalyptus tereticornis open forest on former agricultural land.

2012 ◽  
Vol 18 (4) ◽  
pp. 263 ◽  
Author(s):  
Tom Lewis ◽  
David Taylor ◽  
Scott Swift ◽  
Valerie Debuse
Keyword(s):  
Species Richness ◽  
Plant Regeneration ◽  
Woody Plant ◽  
Agricultural Land ◽  
Livestock Grazing ◽  
Grass Species ◽  
Eucalyptus Tereticornis ◽  
Mature Trees ◽  
Litter Biomass ◽  
Open Forest

We monitored an area that was revegetated with the goal of restoring a Eucalyptus tereticornis open forest on former agricultural land in central, eastern Queensland. Revegetation involved: (1) planting 60 ha of previously cleared and heavily grazed land with eight local trees species; and (2) removing cattle grazing to encourage natural regeneration in areas where some mature trees remained. We compared the revegetation site to native pasture that had also been previously cleared, with only scattered paddock trees remaining, and continued to be managed for livestock production (an area similar to the revegetation site, prior to planting) and a remnant forest (reference area). Nine years since revegetation began there was some evidence that the revegetated site was diverging from pasture in terms of understorey plant composition, sapling density and topsoil C and N. There was little divergence in terms of plant species richness (native, introduced, grass, forb and woody plant richness), herbaceous biomass and woody plant regeneration. Some monitoring plots were subject to fire (prescribed fire and or wildfire) over the period of monitoring. With increasing time since fire, the richness of native species, introduced species and grass species (both native and introduced) declined, and forb and grass species richness declined with increasing litter biomass, suggesting that the occurrence of fire and the associated removal of litter biomass has a positive influence on herbaceous diversity in this ecosystem. Woody plant regeneration persisted through lignotubers at the revegetation site and at the pasture, but this regeneration was stunted at the pasture presumably due to livestock grazing. Hence areas of former E. tereticornis forest showed promising regenerative capacity where mature trees remained and where livestock grazing was removed.

Sound Transmission: a Basis for Dialects in Birdsong?

Behaviour ◽  
1993 ◽  
Vol 124 (3-4) ◽  
pp. 291-312 ◽  
Author(s):  
R.E. Lemon ◽  
E.M. Date
Keyword(s):  
Acoustic Features ◽  
Acoustic Environment ◽  
Several Variables ◽  
Open Forest ◽  
Forest Sites ◽  
American Redstarts ◽  
Song Dialects ◽  
Different Types ◽  
Pure Tones ◽  
Better Than

AbstractThe environmental adaptation hypothesis (EAH) regarding birdsong dialects or ncighbourhoods states that song similarities between neighbouring individuals arise because of common influences on their songs exerted by the acoustic environment of their habitat. An assumption of the hypothesis is that sounds are distorted differently by different types of habitat. A prediction of the hypothesis is that some songs or parts of songs transmit better than others, depending on the habitat of their origin. We tested the assumption and prediction by comparing the attenuation and differential attenuation of pure tones, decreases in modal frequencies of computer simulated songs of American redstarts (Setophaga ruticilla), and the decay of redstart songs and white noise at deciduous, coniferous and open forest sites. The songs were representative of those used by redstarts living in thc three habitats. Results supported the assumption of acoustic differences between habitats but did not support the prediction that some songtypes transmit with less distortion in specific habitats than in others. The EAH also predicts that individuals which inhabit similar vegetation should share more song features than individuals which inhabitat dissimilar vegetation. To test this prediciton samples of songs were taken from the three habitats in different years. There were significant associations by habitat in both samples, but only one of several variables measured was significant and the discriminating variable was not the same for the two periods. Considering together the tests of the assumption and the two predictions, we conclude that for American redstarts evidence of the influence of the acoustic features of habitat on the formation of song dialects is mixed and not convincing.

scholarly journals Timing of fire relative to seed development controls availability of non-serotinous aerial seed banks

2012 ◽  
Vol 9 (11) ◽  
pp. 16705-16751 ◽  
Author(s):  
S. T. Michaletz ◽  
E. A. Johnson ◽  
W. E. Mell ◽  
D. F. Greene
Keyword(s):  
Seed Development ◽  
Picea Glauca ◽  
White Spruce ◽  
Fire Regimes ◽  
Seed Banks ◽  
Conduction Model ◽  
Area Burned ◽  
Spread Model ◽  
In Fire ◽  
Germinable Seed

Abstract. The existence of non-serotinous, non-sprouting species in fire regimes where serotiny confers an adaptive advantage is puzzling, particularly when these species recruit poorly from soil seed banks or from burn edges. In this paper, white spruce (Picea glauca (Moench) Voss) was used to show that the timing of fire relative to seed development can control aerial seed bank availability for non-serotinous species. To estimate seed survival in closed cones during crown fires, cone heating was simulated using a one-dimensional conduction model implemented in a computational fluid dynamics (Navier–Stokes) fire spread model. To quantify the area burned when germinable seed would be contained in closed cones, empirical fire occurrence and seed development (germinability and cone opening) data were compared for multiple locations across the white spruce range. Approximately 12% of cones contained viable seed following crown fire simulations (0.072 m s−1 mean spread rate; 9147 kW m−1 mean intensity), and roughly half of the historical area burned resulted from fires that occurred when closed cones would contain germinable seed. Post-fire recruitment from in situ aerial seed banks can occur for non-serotinous species, and may be an important cause of their existence in fire regimes to which they otherwise seem poorly suited.

scholarly journals Recovery within a population of the Critically Endangered citron-crested cockatoo Cacatua sulphurea citrinocristata in Indonesia after 10 years of international trade control

Oryx ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Alexis J. Cahill ◽  
Jonathan S. Walker ◽  
Stuart J. Marsden
Keyword(s):  
International Trade ◽  
Forest Cover ◽  
Population Data ◽  
Small Population ◽  
Forest Patches ◽  
Field Methods ◽  
Forest Patch ◽  
Forest Sites ◽  
Before And After ◽  
Trade Control

Moratoria on international trade are frequently used to protect threatened species but few studies have examined their effectiveness in allowing populations to recover. We present population data collected before and after a moratorium on trade in the citron-crested cockatoo Cacatua sulphurea citrinocristata, a distinctive subspecies of the yellow-crested cockatoo endemic to Sumba, Indonesia. Before legal trade ceased in 1993 numbers of cockatoos leaving Sumba averaged c. 1,600 per year, and the 1992 population, estimated at 3,200, surely could not sustain such a level of trade. We surveyed cockatoos in four forest patches on Sumba in 1992, and then surveyed these same forest patches 10 years later, using the same field methods. Forest cover within the four patches was similar between years. We recorded a statistically significant increase in overall cockatoo density, from c. 2 birds per km2 in 1992 to >4 per km2 in 2002. Group sizes were also larger in 2002 than in 1992. Densities at two forest sites had increased considerably, at another the population was stable, but at one small forest patch a small population in 1992 had probably decreased. While the population has made a modest recovery, densities remain low compared to cockatoo populations elsewhere. Illegal trade is known to persist and its volume should be monitored closely.

Structure and Composition of the Abrupt Rain-Forest Boundary in the Herberton Highland, North Queensland

1989 ◽  
Vol 37 (5) ◽  
pp. 413 ◽  
Author(s):  
GL Unwin
Keyword(s):  
Structural Changes ◽  
Woody Species ◽  
Fire Regimes ◽  
Forest Edge ◽  
Permanent Sample Plots ◽  
Boundary Change ◽  
Eucalypt Forest ◽  
Open Forest ◽  
Closed Forest ◽  
Forest Boundary

Structural and floristic features of the rainforest-eucalypt forest boundary are described for two sites on the seasonally clouded eastern slopes of the Herberton Highland, north Queensland. Permanent sample plots, transects and canopy profiles were used to analyse variations across the narrow ecotone. The forest ecotone was found highly variable, spatially and temporally. Within rainforest, richness of woody species was maintained through to the closed forest edge. However, structural changes were more pronounced towards the boundary than were floristic variations and a fringe of immature rainforest varied in depth from 20-500 m. In the open forest margin, tall trees of Eucalyptus grandls were restricted to a narrow zone between the rainforest edge and the broad expanse of medium height Eucalyptus intermedia. Within this transition, young rainforest trees and some shrubs were observed, during a 12-year interval, to be establishing beneath tall E. grandis, displacing fire-prone grasses in the process. The distribution of old E. grandis within rainforest provides a record of recent boundary change. On evidence presented, the rainforest-eucalypt forest boundary is dynamic and parts of the rainforest are expanding due to favourable contemporary fire regimes.

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