Open woodland tree and shrub dynamics and landscape function in central Queensland after killing the trees with herbicide

2018 ◽  
Vol 40 (5) ◽  
pp. 473 ◽  
Author(s):  
P. Jones ◽  
T. J. Hall ◽  
R. G. Silcock ◽  
P. G. Filet
Keyword(s):  
Seedling Recruitment ◽  
Woody Species ◽  
Soil Surface ◽  
Grazing Pressure ◽  
Landscape Function ◽  
Landscape Functionality ◽  
Native Pastures ◽  
Eucalypt Woodland ◽  
Control Tree ◽  
Open Woodland

Herbicides are used in savanna to control tree and shrub density, primarily to maintain the value of the country for pastoral enterprises. However, the concomitant effects on biodiversity and landscape functioning need to be recognised and better understood. This study monitored tree and shrub dynamics and eventual landscape functionality in response to tree-killing over 7–8 years at two open eucalypt woodland sites in central Queensland. Paddocks denuded of trees using herbicide or not so treated were subject to three differing grazing pressures by cattle. Similarly treated but ungrazed sets of plots were subjected to either regular spring burns or were rarely burnt. Tree and shrub growth and seedling recruitment were slightly affected by grazing pressure but regular spring burns minimised recruitment of minor woodland species and reduced the population of original saplings and seedlings that survived the herbicide. Few eucalypt seedlings emerged from soil surface samples taken each spring in any treatment, despite the presence of flowering trees in half the treatments. Capture and retention of resources, particularly rainfall and nutrients, were slightly improved by killing the trees, and worsened by grazing. We conclude that killing trees with herbicide at these sites did not adversely affect landscape function and that woody species regeneration was almost inevitable on these open eucalypt woodland native pastures.

Grazing Gradients in Central Australian Rangelands: Ground Verification of Remote Sensing-Based Approaches.

1993 ◽  
Vol 15 (2) ◽  
pp. 217 ◽  
Author(s):  
GN Bastin ◽  
AD Sparrow ◽  
G Pearce
Keyword(s):  
Satellite Data ◽  
Vegetation Cover ◽  
Field Data ◽  
Graphical Representation ◽  
Woody Species ◽  
Soil Surface ◽  
Grazing Pressure ◽  
Remotely Sensed Data ◽  
Suitable Technique ◽  
Grazing Behaviour

Remotely-sensed data collected by satellites have been proposed for investigating grazing effects across the large paddocks of arid Australia. These data are used to compute indices of vegetation cover which are then analysed with reference to patterns of grazing behaviour around watering points. Grazing pressure typically increases as water is approached, resulting in a decrease in herbage cover. This pattern of cover change is called a grazing gradient. The change in these gradients from a dry to wet period forms the basis for assessing land degradation as described in an accompanying paper. This study demonstrates that grazing gradients do exist, that they can be detected with field-based methods of data collection, and that there is close correspondence between ground data and indices of vegetation cover obtained from contemporary Landsat Multispectral Scanner satellite data. Field data representing aerial cover of the herbage and woody species layers were collected along transects radiating away from water at two sites grazed by cattle in central Australia. Graphical representation of the litter and herbage components demonstrate that gradients of decreasing cover attributable to increasing grazing pressure occur along all, or sections, of each transect. Highly significant correlations exist between the field data and satellite indices of vegetation cover. Localised shrub increase and patches of recent erosion obscured trends of increasing cover with distance from water on parts of some transects. Soil surface state (describing past erosion) was a significant covariate of cover change at one site. Our ability to characterise gradients of increasing vegetation cover with distance from water using both field and satellite data should mean that the grazing gradient method, when used with satellite data, is a suitable technique for assessing the extent of landscape recovery following good rainfall.

Demography of three perennial grasses in a central Queensland eucalypt woodland

2009 ◽  
Vol 31 (4) ◽  
pp. 427 ◽  
Author(s):  
P. Jones ◽  
P. Filet ◽  
D. M. Orr
Keyword(s):  
Life Span ◽  
Seedling Recruitment ◽  
Negative Impact ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Seasonal Rainfall ◽  
Severe Drought ◽  
Heteropogon Contortus ◽  
Heavy Grazing ◽  
Eucalypt Woodland

The population dynamics of the palatable, perennial grasses Bothriochloa ewartiana (Domin) C.E.Hubb. (desert Mitchell grass), Chrysopogon fallax S.T.Blake (golden beard grass) and Heteropogon contortus (L.) P.Beauv. ex Roem. & Schult. (black speargrass), were studied in an extensive grazing study conducted in a eucalypt woodland within the Aristida–Bothriochloa pasture community in central Queensland between 1994 and 2000. Treatments were three grazing pressures based on light, medium and heavy utilisation of forage available at the end of summer and two timber treatments (trees intact and trees killed). Seasonal rainfall throughout this study was generally favourable for plant growth with no severe drought periods. Grazing pressure had a greater overall impact on plant dynamics than timber treatment, which had minimal impact. Grazing pressure had a large impact on H. contortus dynamics, an intermediate impact on B. ewartiana and no impact on C. fallax. Fluctuations in plant density of both B. ewartiana and C. fallax were small because both species were long lived with low levels of seedling recruitment and plant death, whereas fluctuations in H. contortus density were relatively high because of its relatively short life span and higher levels of both recruitment and death. Heavy grazing pressure increased the recruitment of B. ewartiana and H. contortus in some years but had no impact on that of C. fallax. Heavy grazing pressure reduced the survival of the original plants of both B. ewartiana and H. contortus but not of C. fallax. For H. contortus, the size of the original plants was larger where trees were killed than where trees were left intact and plants of the 1995 seedling cohort were larger in 1998 at heavy compared with those at light and medium grazing pressure. Grazing had a minor negative impact on the soil seed bank of H. contortus. Populations of all three species remained stable throughout this study, although the favourable seasonal rainfall experienced and the short duration of this study relative to the life span of these species may have masked longer term, deleterious impacts of heavy grazing pressure.

scholarly journals Slow-release fertilizers and possibilities of their utilizing in nursery

2004 ◽  
Vol 52 (2) ◽  
pp. 155-164
Author(s):  
Petr Salaš
Keyword(s):  
Slow Release ◽  
Ornamental Plants ◽  
Woody Species ◽  
Soil Surface ◽  
Berberis Thunbergii ◽  
Slow Release Fertilizers ◽  
Picea Omorika ◽  
One Year ◽  
Two Stages

Reserve, slow-release fertilizers (SRF) enable to simplify the whole system of plant nutrition and fertilisation. Tabletted fertilizers of the Silvamix series represent a prospective product of Czech provenience. At our university, these fertilizers have been tested and used since the year 1991. Ornamental woody species grown in containers were investigated in two stages. Experiments with ornamental plants were established using one-year-old cuttings and seedlings of the following deciduous and evergreen woody species:Cotoneaster dammeri Skogholm,Berberis thunbergii,Potentilla fruticosa Snowflake,Ligustrum vulgare AtrovirensandPicea omorika. After planting into containers, fertilizers in the dose of 1 tablet (i.e. 10 g) per litre of substrate were applied either to roots level or on the soil surface in the container. Silvamix in the dose of 5 g.l-1was used as the tested fertilizer in the second stage. It was applied during the planting in the form of tablets and/or a powder. Control plants were fertilized in the course of growing season using a common agricultural fertilizer Cererit Z. The annual plants increments were measured. These experiments demonstrated a long-term optimum effect of this product on woody species and an equal quality and efficiency of its tabletted and powdered forms.

Seasonal variation in soil seed bank size and species composition of selected habitat types in Maputaland, South Africa

Bothalia ◽  
2007 ◽  
Vol 37 (2) ◽  
pp. 249-258 ◽  
Author(s):  
M. J. S. Kellerman ◽  
M. W. Van Rooyen
Keyword(s):  
South Africa ◽  
Seasonal Variation ◽  
Species Composition ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Woody Species ◽  
Forest Edge ◽  
Seed Banks ◽  
Habitat Types ◽  
Open Woodland

Seasonal variation in seed bank size and species composition of five selected habitat types within the Tembe Elephant Park. South Africa, was investigated. At three-month intervals, soil samples were randomly collected from five different habitat types: a, Licuati forest; b, Licuati thicket; c, a bare or sparsely vegetated zone surrounding the forest edge, referred to as the forest/grassland ecotone; d, grassland; and e, open woodland. Most species in the seed bank flora were either grasses, sedges, or forbs, with hardly any evidence of woody species. The Licuati forest and thicket soils produced the lowest seed densities in all seasons.  Licuati forest and grassland seed banks showed a two-fold seasonal variation in size, those of the Licuati thicket and woodland a three-fold variation in size, whereas the forest/grassland ecotone maintained a relatively large seed bank all year round. The woodland seed bank had the highest species richness, whereas the Licuati forest and thicket soils were poor in species. Generally, it was found that the greatest correspondence in species composition was between the Licuati forest and thicket, as well as the forest/grassland ecotone and grassland seed bank floras.

Vegetation History and Water Fluctuations at Lake Leake, South-Eastern South Australia. II. 50 000 B.P. To 10 000 B.P

1975 ◽  
Vol 23 (5) ◽  
pp. 815 ◽  
Author(s):  
JR Dodson
Keyword(s):  
Vegetation History ◽  
South Australia ◽  
Annual Rainfall ◽  
Drill Core ◽  
Radiocarbon Dates ◽  
Last Glaciation ◽  
Annual Minimum Temperature ◽  
Average Annual Rainfall ◽  
Eucalypt Woodland ◽  
Open Woodland

A drill core from Lake Leake contains a sedimentary sequence extending from about 50,000 B.P. until the present. This paper discusses the results of the pollen analyses and six radiocarbon dates which span the period from about 50,000 until about 10,000 B.P. There are core sections which yielded low numbers of pollen and thus there are gaps in the vegetation record. It is suggested that open eucalypt woodland was replaced by eucalypt woodland with heath at about 50,000 B.P. and remained until about 39,000 B.P. Open woodland then returned but was replaced by eucalypt woodland with heath by 38,000 B.P. Some time after 35,000 B.P., open eucalypt woodland conditions returned and persisted until near 10,000 B.P. when Casuarina stricta migrated into the area. Through- out the period in question the climate was drier than it has been in the last 10,000 radiocarbon years. There were wet periods about 50,000 and 39,000 B.P. and from 38,000 to 35,000 B.P. The character of the sediments and the relative amounts of pollen preserved suggest that conditions were relatively dry from 50,000 to 39,000 B.P. and from after 35,000 until near 10,000 B.P. The lake was driest during the period of the last glaciation but the presence of eucalypt pollen is interpreted as indicating that the average annual minimum temperature was above 10�C and the average annual rainfall was above 20-25 cm.

Postfire Regeneration of a Mediterranean Heathland in Southern Spain

1996 ◽  
Vol 6 (4) ◽  
pp. 191 ◽  
Author(s):  
F Ojeda ◽  
T Maranon ◽  
J Arroyo
Keyword(s):  
Woody Species ◽  
Soil Surface ◽  
Calluna Vulgaris ◽  
Community Diversity ◽  
Southern Spain ◽  
Strait Of Gibraltar ◽  
Vegetative Organs ◽  
Wild Fire ◽  
Postfire Regeneration

Fire is a recurrent disturbance in the vegetation of Mediterranean climate regions. Most of the woody species (16 out of 19) in a Mediterranean heathland community, in the Strait of Gibraltar region of southern Spain, sprouted from subterranean vegetative organs after a wild-fire. Dominant sprouters were the prostrated oak Quercus lusitanica, three gorses, Genista tridens, G. tridentata and Stauracanthus boivinii, and a heath, Erica scoparia. About 100 seedlings m-2 of 14 woody species were censused in the first three years after fire. The highest density of seedlings was recorded for heather (Calluna vulgaris), a rockrose (Cistus populifolius subsp. major) and a gorse (Genista triacanthos). Woody vegetation covered up to 85% of the soil surface in the third year after fire. At this stager the community was co-dominated by the sprouters Quercus lusitanica (21%), Genista tridentata (21%) and Stauracanthus boivinii (20%), and the seeder Cistus populifolius subsp. major (20%). A total of 52 herbaceous species, many of them (35) perennials, was recorded, showing a temporal change in species composition. The role of fire influencing community diversity and the consequences for the conservation of heathlands in the Strait of Gibraltar region, are discussed.

Effect of Kochia (Kochia scoparia) Interference on Sunflower (Helianthus annuus) Yield

Weed Science ◽  
2014 ◽  
Vol 62 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Derek W. Lewis ◽  
Robert H. Gulden
Keyword(s):  
Great Plains ◽  
Growth And Development ◽  
Seed Quality ◽  
Seedling Recruitment ◽  
Soil Surface ◽  
Northern Great Plains ◽  
Limited Information ◽  
Leaf Stage ◽  
Action Threshold ◽  
Sunflower Crop

Kochia is a weed found in many sunflower fields across the Northern Great Plains. There is limited information about the ability of sunflower plants to compete with kochia, specifically when the weed grows both in the crop row and in the inter-row space, as in zero tillage systems that rely solely on herbicides to manage weeds. An experiment was conducted over seven site–yr, from 2009 to 2011, to determine the effect of kochia density and relative time of kochia seedling recruitment on sunflower growth and development, yield and seed quality. Kochia seed was broadcast on the soil surface at six densities, into sunflowers planted in 75-cm rows, either at the same time as the sunflower crop was planted (early weed seedling recruitment), or when the sunflowers were at the four-leaf stage (late weed seedling recruitment). When kochia plants emerged at the same time as the sunflowers, yield was reduced by up to 76% and sunflower head diam was reduced in four site–yr, stem diam was reduced in three site–yr, height was reduced in two site–yr and the number of leaves per sunflower plant was reduced in two site–yr The 5% action threshold for early emerging kochia was four kochia plants m−2in the combined site–yr analysis. Additionally, early recruiting kochia seedlings reduced sunflower seed size and seed weight at two and three site–yr, respectively. Kochia plants that emerged after the four-leaf stage of the sunflower crop did not affect sunflower growth and development, yield, or seed quality. To reduce the potential for yield and seed quality losses, sunflower growers should be proactive with respect to managing kochia in sunflowers, particularly when the kochia plants emerge at about the same time as the sunflowers.

Summer Grazing Management of a White Clover-Bahiagrass Pasture: Legume Survival

1986 ◽  
Vol 22 (4) ◽  
pp. 363-371 ◽  
Author(s):  
B. H. Dzowela ◽  
G. O. Mott ◽  
W. R. Ocumpaugh
Keyword(s):  
White Clover ◽  
Seedling Recruitment ◽  
Grazing Pressure ◽  
Grazing Management ◽  
Primary Mechanism ◽  
Heavy Grazing ◽  
Seed Reserves ◽  
Survival Potential ◽  
Summer Grazing ◽  
Pasture Legume

SUMMARYA grazing management study involving the new white clover cultivar Osceola grown in association with Bahiagrass cv. Pensacola was conducted on wet and dry sites with and without pesticide/herbicide treatment. A combination of heavy grazing pressure and a short deferment period before grazing during the summer and autumn resulted in the largest soil seed reserves and seedling recruitment by the white clover component. However, maximum survival of plants was recorded from a combination of a short deferment period and moderate grazing pressure.A slight increase in plant survival and seedling recruitment was shown on the wet site. Survival potential was least in pasture treated with pesticide and herbicide. Heavy grazing pressure and short deferment periods appear essential for the survival of the clover component. Annual seedling recruitment from soil seed reserves was the primary mechanism of white clover survival from spring to spring in pasture associations based on tropical bahiagrass.

Microhabitat availability and seedling recruitment ofLobelia urens: a rare plant species at its geographical limit

2000 ◽  
Vol 10 (4) ◽  
pp. 471-487 ◽  
Author(s):  
J.M. Dinsdale ◽  
M.P. Dale ◽  
M. Kent
Keyword(s):  
Large Scale ◽  
Seedling Recruitment ◽  
Higher Plants ◽  
Plant Cover ◽  
Soil Surface ◽  
Potential Effect ◽  
Plant Litter ◽  
Higher Plant ◽  
Precise Role

AbstractIn Britain,Lobelia urens(L.) (the heath lobelia) occurs in rough grassland, is rare and only found in southern England, where it is at the northern limit of its range. Emergence and survival ofL. urenswas investigated at six locations in two geographically distinct sites experiencing spring, autumn or no grazing in two consecutive years. Four factors were evaluated qualitatively, as a means of characterizing microhabitats for germination and survival: all permutations of higher plant cover, bryophytes, plant litter and surface depressions. The potential effect of adjacent plants on recruitment was also assessed using the nearest neighbour distance (NND). Grazing created depressions, removed plant litter and increased the proportion of sites with higher plant cover. It also resulted in a more open sward with higher NNDs. None of these changes stimulated recruitment. Instead, small increases in the frequency of some rare or very rare microhabitat types were vital in making grazed rough grassland more suitable for emergence. Reduced litter loads and a greater quantity of moss were two key responses. Overall, survival ofL. urenswas less than 1% and was particularly favoured by moss and an increase in NNDs. Shading from higher plants, with or without plant litter, decreased emergence, but the precise role of litter was complex and most probably related to its quantity. In an experimental seed bed, only empty depressions favoured emergence. The microhabitat relationships ofL. urenswere unusually consistent among locations and consecutive years.L. urensrequires high soil surface temperatures but also adequate water for large scale recruitment, and such conditions are encouraged by grazing. The particular problems of experimental design and statistical analysis of data from recruitment experiments are also discussed.

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