Comparative demography of co-occurring introduced and native tussock grasses: persistence and potential expansion

Oecologia ◽  
1990 ◽  
Vol 82 (4) ◽  
pp. 537-543 ◽  
Author(s):  
David A. Pyke
Keyword(s):  
Comparative Demography ◽  
Tussock Grasses

scholarly journals Comparative demography of the exotic Harmonia axyridis with other aphidophagous coccinellids reared on artificial diet

2014 ◽  
Vol 49 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Julianne Milléo ◽  
Francisco Sales Fernandes ◽  
Wesley Augusto Conde Godoy
Keyword(s):  
Life Table ◽  
Harmonia Axyridis ◽  
Reproductive Rate ◽  
The Other ◽  
Adult Longevity ◽  
Net Reproductive Rate ◽  
Anagasta Kuehniella ◽  
Survival Percentage ◽  
Comparative Demography ◽  
Biological Aspects

The objective of this work was to compare biological aspects and life table parameters of the coccinellids Harmonia axyridis, Cycloneda sanguineaand Hippodamia convergens. Insects were fed eggs of Anagasta kuehniella, and reared at 24.5±1ºC, 70±10% relative humidity, with a 12 hour photophase. Hippodamia convergenstook about 1.6 day to complete development, longer than H. axyridis, and 2.4 day longer than C. sanguinea.At immature stages, H. axyridisexhibited the highest survival percentage (49.2%), in comparison to the other coccinellids. For mean adult longevity, H. convergenswas deficient, in comparison with the other species. Mean period of pre oviposition was the longest in C. sanguinea; the longest oviposition time occurred for H. axyridis; and the post oviposition period was similar between the coccinellids. Considering the reproductive parameters, H. axyridisshowed the best performance in all aspects. For life table, the values of H. convergenswere higher than, although close, to those of H. axyridis. Nevertheless, the high net reproductive rate of H. axyridis showed this species potential to increase population size. The biological characteristics of the exotic H. axyridis favors its invasion and establishment in Brazil, corroborating results noticed in other countries.

Comparative demography of increasing and stable populations of blue grouse (Dendragapus obscurus)

1975 ◽  
Vol 53 (1) ◽  
pp. 1-11 ◽  
Author(s):  
J. A. Redfield
Keyword(s):  
Mortality Rates ◽  
Demographic Characteristics ◽  
Dendragapus Obscurus ◽  
Comparative Demography ◽  
Reproductive Rates ◽  
Stable Populations

The demographic characteristics of an increasing population of blue grouse were studied from 1968 to 1971. Increasing populations of grouse had high reproductive rates and slightly higher than average mortality rates among females as compared to stable populations.

Effect of fire regime on the grass community of the humid savanna of Lamto, Ivory Coast

2018 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Kouamé Fulgence Koffi ◽  
Aya Brigitte N’Dri ◽  
Jean-Christophe Lata ◽  
Souleymane Konaté ◽  
Tharaniya Srikanthasamy ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Ivory Coast ◽  
Fire Regime ◽  
Fire Regimes ◽  
Abundant Species ◽  
Grass Species ◽  
The Third ◽  
Humid Savanna ◽  
The Impact ◽  
Tussock Grasses

AbstractThis study assesses the impact of four fire treatments applied yearly over 3 y, i.e. early fire, mid-season fire, late fire and no fire treatments, on the grass communities of Lamto savanna, Ivory Coast. We describe communities of perennial tussock grasses on three replicated 5 × 5-m or 10 × 5-m plots of each fire treatment. Tussock density did not vary with fire treatment. The relative abundance of grass species, the circumference of grass tussocks and the probability of having a tussock with a central die-back, varied with fire treatment. Mid-season fire had the highest proportion of tussocks with a central die-back while the late fire had the smallest tussocks. Tussock density, circumference, relative abundance and probability of having a central die-back varied with species. Andropogon canaliculatus and Hyparrhenia diplandra were the most abundant of the nine grass species. They had the largest tussocks and the highest proportion of tussock with a central die-back. Loudetia simplex was the third most abundant species but was very rare in no fire plots. The distribution of tussock circumferences was right skewed and dominated by small tussocks. The proportion of the tussocks with a central die-back strongly increased with circumference, which could lead to tussock fragmentation. Taken together, this study suggests that fire regimes impact grass demography and that this impact depends on grass species and tussock size.

scholarly journals Comparative Demography of Skates: Life-History Correlates of Productivity and Implications for Management

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e65000 ◽  
Author(s):  
Lewis A. K. Barnett ◽  
Megan V. Winton ◽  
Shaara M. Ainsley ◽  
Gregor M. Cailliet ◽  
David A. Ebert
Keyword(s):  
Life History ◽  
Comparative Demography

scholarly journals Defoliation Tolerance and Ammonium Uptake Rate in Perennial Tussock Grasses

2004 ◽  
Vol 57 (1) ◽  
pp. 82 ◽  
Author(s):  
Carolina Saint Pierre ◽  
Carlos Alberto Busso ◽  
Oscar Montenegro ◽  
Gustavo D. Rodriguez ◽  
Hugo D. Giorgetti ◽  
...  
Keyword(s):  
Uptake Rate ◽  
Ammonium Uptake ◽  
Tussock Grasses

scholarly journals Night Parrots Pezoporus occidentalis at the Ethel River, Western Australia: Continuing opportunities for conserving habitats around rare permanent springs

2021 ◽  
Vol 38 ◽  
pp. 164-171
Author(s):  
Peter Curry ◽  
Charles Nicholson ◽  
Boyd Wykes
Keyword(s):  
20Th Century ◽  
Western Australia ◽  
Perennial Grasses ◽  
Land Uses ◽  
Protective Measures ◽  
The Future ◽  
Under Construction ◽  
Tussock Grasses

The combined records of two 20th-century observers (Martin Bourgoin and Julian Ford) of Night Parrots Pezoporus occidentalis at permanent springs on the Ethel River amount to more published records of this elusive bird over a longer timespan (1912–1964) than anywhere else in Western Australia. Likely Night Parrot habitats persisting in the Ethel River area in 2019–2020 include extensive areas of mature Limestone Spinifex Triodia wiseana with other native perennial grasses, hard spinifex on sandplains, patchy perennial tussock grasses on minor floodplains and chenopod shrublands including perennial saltbush. We evaluate these habitats for their past uses and likely continuing changes that might have affected Night Parrots. With a mine under construction upstream in the sub-catchment headwaters and indications that the species is not extinct in the district, there is an urgent need to raise awareness of a uniquely important area and to survey the area for the species. Monitoring and coordinating protective measures across intersecting land uses is likely to improve the future of rare permanent springs and sensitive habitats.

scholarly journals At a Microsite Scale, Native Vegetation Determines Spatial Patterns and Survival of Pinus contorta Invasion in Patagonia

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 654 ◽  
Author(s):  
Bárbara Langdon ◽  
Lohengrin A. Cavieres ◽  
Aníbal Pauchard
Keyword(s):  
Plant Species ◽  
Pinus Contorta ◽  
Point Pattern Analysis ◽  
Point Pattern ◽  
Native Vegetation ◽  
Native Plant ◽  
Patagonian Steppe ◽  
Stressful Environment ◽  
Management Actions ◽  
Tussock Grasses

Research Highlights: The invasive species Pinus contorta, has become a new component of the vegetation in the Patagonian Steppe, invading the complex matrix of bare ground, tussock grasses and cushion plants. At a microsite scale, the type of native vegetation is one of the multiple factors determining the establishment of P. contorta and in some cases, increasing its survival, and as a result, the invasion of the species. Background and Objectives: The presence of trees, particularly pines, where they are naturally absent, represents a clear threat to Patagonian steppe ecosystems. Thus, understanding the interaction between pines and native plant species may be the key to understanding the invasion and applying management actions. Pinus contorta is considered one of the most aggressive among the pines species, with recognized impacts on regions in the southern hemisphere and Europe, and it is one of the main invaders in the Patagonian steppe. Our aim in this study is to determine the influence of surrounding vegetation on P. contorta spatial distribution, its establishment and future development in the Chilean Patagonia. Materials and Methods: We used point pattern analysis to determine the existence of spatial associations between P. contorta and the resident vegetation of the Patagonian steppe. Further, a seeding experiment was carried out to assess the influence of the surrounding vegetation during P. contorta establishment and first growing season. Results: We found that young P. contorta individuals are positively associated with the native cushion plant B. magellanica and also to tussock grasses. Seeding experiments showed that P. contorta is influenced by resident plant species during establishment and is able to establish on any ground cover type in the Patagonian steppe, but some resident plant species increase P. contorta survival chances. Conclusions: Pinus contorta is interacting with native vegetation and becoming an active component of the Patagonian steppe mosaic. Although pines can establish in any type of vegetation in the Patagonian steppe mosaics, native cushion and tussock grasses may be facilitating the process and promoting pine survival, allowing it to survive and thrive in this stressful environment.

scholarly journals Comparative demography of commercially important species of coral grouper, Plectropomus leopardus and P. laevis , from Australia's great barrier reef and Coral Sea marine parks

2020 ◽  
Vol 97 (4) ◽  
pp. 1165-1176
Author(s):  
Samuel D. Payet ◽  
Jake R. Lowe ◽  
Bruce D. Mapstone ◽  
Morgan S. Pratchett ◽  
Tane H. Sinclair‐Taylor ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Barrier Reef ◽  
Important Species ◽  
Coral Sea ◽  
Comparative Demography ◽  
Commercially Important ◽  
Plectropomus Leopardus

Comparative demography of a rare species in Florida scrub and road habitats

2007 ◽  
Vol 137 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Pedro F. Quintana-Ascencio ◽  
Carl W. Weekley ◽  
Eric S. Menges
Keyword(s):  
Rare Species ◽  
Florida Scrub ◽  
Comparative Demography
Sign in / Sign up

Export Citation Format

Share Document