Grasstree (Xanthorrhoea preissii) recovery after fire in two seasons and habitats

2005 ◽  
Vol 53 (6) ◽  
pp. 509 ◽  
Author(s):  
Dylan Korczynskyj ◽  
Byron B. Lamont
Keyword(s):  
Reproductive Success ◽  
Production Rate ◽  
Early Summer ◽  
Growth Patterns ◽  
Late Spring ◽  
Leaf Longevity ◽  
Fire Season ◽  
Leaf Production ◽  
Growing Conditions

To distinguish fire-stimulated growth from the underlying growth patterns imposed by season, we measured leaf production of Xanthorrhoea preissii Endl. (Xanthorrhoeaceae). We compared unburnt with spring- and autumn-burnt sites in forest and woodland habitats. Following fire, X. preissii responded with accelerated leaf production, regardless of season. Rapid leaf production during the initial flush of growth was partly at the expense of starch reserves in the stem, at least after autumn fire. Although this initial flush was relatively short-lived after fire in both seasons (12–32 weeks), the effect of fire on leaf production was sustained for up to 20 months, accompanied by a significant reduction in leaf longevity. Mean maximum leaf production rate was higher for spring-burnt grasstrees (up to 6.1 leaves day–1) than those burnt in autumn (up to 4.5 leaves day–1), associated with seasonally optimal growing conditions in late spring–early summer. Similarly, the timing of autumn burns in relation to declining temperature with the approach of winter appeared to dictate how rapidly grasstrees recovered. The consequences of fire season could have implications for the reproductive success of X. preissii.

scholarly journals MANAGEMENT OF LATE SPRING-EARLY SUMMER PASTURE SURPLUSES IN HILL COUNTRY

1984 ◽  
pp. 199-206 ◽  
Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly
Keyword(s):  
Early Spring ◽  
Early Summer ◽  
Late Spring ◽  
First Year ◽  
Hill Country ◽  
Continuous Grazing ◽  
Summer Pasture ◽  
Animal Performances ◽  
Grazing Policy ◽  
Made In

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control

scholarly journals Seasonal patterns of pasture production in the Bay of Plenty and Waikato

1991 ◽  
pp. 67-72
Author(s):  
J.A. Baars ◽  
G.J. Goold ◽  
M.F. Hawke ◽  
P.J. Kilgarriff ◽  
M.D. Rolm
Keyword(s):  
Growth Rates ◽  
Early Spring ◽  
Early Summer ◽  
Growth Patterns ◽  
Climatic Data ◽  
Large Contribution ◽  
Pasture Production ◽  
Summer Peak ◽  
The Difference

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates

Development of a nutritional strategy for increasing lamb survival in Merino ewes mated in late spring/early summer

1998 ◽  
Vol 52 (3) ◽  
pp. 213-219 ◽  
Author(s):  
M.B Nottle ◽  
D.O Kleemann ◽  
V.M Hocking ◽  
T.I Grosser ◽  
R.F Seamark
Keyword(s):  
Early Summer ◽  
Late Spring ◽  
Nutritional Strategy ◽  
Lamb Survival

scholarly journals Drought impacts on vegetation in the pre- and post-fire events over Iberian Peninsula

2012 ◽  
Vol 12 (10) ◽  
pp. 3123-3137 ◽  
Author(s):  
C. M. Gouveia ◽  
A. Bastos ◽  
R. M. Trigo ◽  
C. C. DaCamara
Keyword(s):  
Iberian Peninsula ◽  
Water Availability ◽  
Vegetation Dynamics ◽  
Early Summer ◽  
Fire Season ◽  
Drought Severity ◽  
Vegetation Density ◽  
Remotely Sensed Data ◽  
Recovery Times ◽  
The Impact

Abstract. The present work aims to study the combined effect of drought and large wildfires in the Iberian Peninsula relying on remotely sensed data of vegetation dynamics and leaf moisture content, in particular monthly NDVI, NDWI and NDDI time series from 1999–2009, derived from VEGETATION dataset. The impact of the exceptional 2004/2005 drought on vegetation was assessed for vegetation recovering from the extraordinary fire season of 2003 and on the conditions that contributed to the onsetting of the fire season of 2005. Drought severity was estimated by the cumulative negative effect on photosynthetic activity (NDVI) and vegetation dryness (NDDI), with about 2/3 of Iberian Peninsula presenting vegetative stress and low water availability conditions, in spring and early summer of 2005. Furthermore, NDDI has shown to be very useful to assess drought, since it combines information on vegetation and water conditions. Moreover, we show that besides looking at the inter-annual variability of NDVI and NDDI, it is useful to evaluate intra-annual changes (δNDVI and δNDDI), as indicators of change in vegetation greenness, allowing a detailed picture of the ability of the different land-cover types to resist to short-term dry conditions. In order to assess drought impact on post-fire regeneration, recovery times were evaluated by a mono-parametric model based on NDVI data and values corresponding to drought months were set to no value. Drought has shown to delay recovery times for several months in all the selected scars from 2003. The analysis of vegetation dynamics and fire selectivity in 2005 suggests that fires tended to occur in pixels presenting lower vegetative and water stress conditions during spring and early summer months. Additionally, pre-fire vegetation dynamics, in particular vegetation density and water availability during spring and early summer, has shown to influence significantly the levels of fire damage. These results stress the role of fuel availability in fire occurrence and impact on the Iberian Peninsula.

scholarly journals Compost and soil moisture effects on seasonal carbon and nitrogen dynamics, greenhouse gas fluxes and global warming potential of semi-arid soils

2019 ◽  
Vol 8 (S1) ◽  
pp. 367-376 ◽  
Author(s):  
Mavis Badu Brempong ◽  
Urszula Norton ◽  
Jay B. Norton
Keyword(s):  
Global Warming ◽  
Soil Moisture ◽  
Global Warming Potential ◽  
Carbon Dioxide Emissions ◽  
Inorganic Nitrogen ◽  
Early Summer ◽  
Late Spring ◽  
Late Winter ◽  
Normal Soil ◽  
Soil Inorganic

Abstract Purpose An 8-week incubation study was conducted to monitor soil inorganic nitrogen (N), dissolved organic carbon (DOC), greenhouse gases (GHG) [CO2, N2O and CH4] and cumulative global warming potential (GWP) in dryland soil. Methods Soil was amended with variable rates of compost (zero, 15, 30 and 45 dry Mg ha−1) and soil moistures [5% (dry), 7% (normal) and 14% (wet) water filled pore space (WFPS)] and experienced biweekly temperature transitions from 5 °C (late winter) to 10 °C (early spring) to 15 °C (late spring) to 25 °C (early summer). Results The addition of 30 and 45 Mg ha−1 compost enhanced N mineralization with 13% more soil inorganic N (7.49 and 7.72 µg Ng−1 day−1, respectively) during early summer compared with lower compost rates. Normal and wet soils had 35% more DOC in the late spring (an average of 34 µg g−1 day−1) compared to the dry WFPS, but transitioning from late spring to early summer, DOC at all soil WFPS levels increased. Highest rates of compost were not significant sources of GHG with normal soil WFPS, compared with lower compost rates. Carbon dioxide emissions increased by 59 and 15%, respectively, as soil WFPS increased from dry to normal and normal to wet. Soils with normal WFPS were the most effective CH4 sink. Conclusion One-time application of high compost rates to dryland soils leads to enhanced N and C mineralization under normal soil moisture and warmer temperature of the summer but will not pose significant global warming dangers to the environment through GHG emissions since soils are rarely wet.

Animal production from pasture with and without conservation for winter feeding

1957 ◽  
Vol 1957 ◽  
pp. 17-31
Author(s):  
D. E. Eyles
Keyword(s):  
Early Summer ◽  
Animal Production ◽  
Late Spring ◽  
Summer Drought ◽  
Constant Number ◽  
Seasonal Growth ◽  
Main Obstacle ◽  
Summer Grazing ◽  
Winter Feeding

The uneven seasonal growth of herbage is the main obstacle to the more efficient utilisation of grassland. There is an abundance of growth in late spring and early summer and a scarcity during a summer drought and in winter. Heavy stocking in spring followed by lighter stocking in summer is a suitable management for fattening sheep and cattle because they can be sold fat from June onwards, but a constant number of livestock has to be maintained throughout the year on many farms which carry breeding or growing animals. On these farms grassland, besides giving summer grazing, is expected to provide the bulk of the fodder for over-wintering. It is doubtful whether the results of grazing experiments which evaluate summer grazing only can be applied to these farms.

The effect of leaf phenology of overstory trees on the reproductive success of an understory shrub, Staphylea bumalda DC

2000 ◽  
Vol 78 (6) ◽  
pp. 781-785 ◽  
Author(s):  
Hanako Maeno ◽  
Tsutom Hiura
Keyword(s):  
Reproductive Success ◽  
Resource Limitation ◽  
Fruit Production ◽  
Early Summer ◽  
Leaf Phenology ◽  
Species Variation ◽  
Broad Leaved Forest ◽  
Leaved Forest ◽  
Leafing Date ◽  
Canopy Species

The effects of the leaf phenology of canopy trees on the reproductive success of an entomophilous, self-incompatible shrub, Staphylea bumalda DC. were examined in a deciduous broad-leaved forest in northern Japan. The amount of light reaching a particular understory shrub from spring to early summer was determined by the leafing date of surrounding canopy species. Variation in leafing date of canopy species affected flower and fruit production by the understory shrub. These results suggest that reproductive success of understory shrubs depends in part on the leaf phenology of canopy trees.Key words: phenology, deciduous broad-leaved forest, fruit set, resource limitation.

Fruit viability on grubbed Nassella trichotoma (Nees) tussocks

2002 ◽  
Vol 42 (8) ◽  
pp. 1057 ◽  
Author(s):  
S. Lamoureaux ◽  
G. Bourdôt
Keyword(s):  
New Zealand ◽  
High Risk ◽  
Developmental Stage ◽  
Root System ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Leaf Sheath ◽  
Early Summer ◽  
Late Spring ◽  
Summer Fruit

An experiment was conducted to determine the influence of time of grubbing in the late spring–early summer, panicle developmental stage at grubbing, and the presence or absence of roots on grubbed plants, on the initial and post-senescent viability of fruits of Nassella trichotoma in North Canterbury, New Zealand. The percentage of fruits viable, following desiccation of panicles removed from plants grubbed in the field, increased from 1% for panicles just beginning to emerge from the leaf sheath, to 49% for panicles fully extended at the time of grubbing. Similarly, as grubbing date was delayed from late November (late spring) until late December (early summer), fruit viability increased from 0.3 to 47%. Overall, 36% of the fruits were viable on panicles at the time of grubbing, increasing slightly to 47 and 44%, respectively, after a period of desiccation with and without the panicles being attached to the grubbed plant's root system. It was concluded that if recruitment of fruits of N. trichotoma to the soil seed bank is to be prevented in North Canterbury, plants must be uprooted before panicle extension. Delaying grubbing to when panicles are fully extended, while possibly enabling a higher percentage of plants to be detected and therefore destroyed, carries with it a high risk of permitting the recruitment of viable fruits to the soil seed bank.

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