scholarly journals Themeda quadrivalvis (grader grass).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Dominican Republic ◽  
Seedling Establishment ◽  
Agricultural Land ◽  
New Caledonia ◽  
Indian Subcontinent ◽  
Fire Regimes ◽  
Ecosystem Change ◽  
South East Asia ◽  
Annual Grass ◽  
Disturbed Areas

Abstract Themeda quadrivalvis is an annual grass found as a weed in grasslands, disturbed areas and agricultural land. It is native to the Indian Subcontinent and South East Asia but has been widely introduced to the Americas, Africa and Oceania. It is recorded as invasive in Mexico, Cuba, Dominican Republic, Reunion, Australia, Fiji and New Caledonia. It is spread unintentionally as a contaminant in straw packing, pasture seed and on vehicles and machinery. Once established, it forms dense thickets that prevent seedling establishment; this causes ecosystem change, altered fire regimes and reduced native biodiversity.

Bird assemblages in isolated Ficus trees in Kenyan farmland

2006 ◽  
Vol 22 (6) ◽  
pp. 723-726 ◽  
Author(s):  
G. W. Eshiamwata ◽  
D. G. Berens ◽  
B. Bleher ◽  
W. R. J. Dean ◽  
K. Böhning-Gaese
Keyword(s):  
Tropical Forests ◽  
Forest Fragmentation ◽  
Seedling Establishment ◽  
Agricultural Land ◽  
Agricultural Landscapes ◽  
Forest Patches ◽  
Frugivorous Birds ◽  
Fragmented Forest ◽  
Important Group ◽  
Disturbed Areas

Over the last few decades a rapid and extensive conversion of tropical forests to agricultural land has taken place resulting in mosaics of fragmented forest patches, pastures and farmland. While the effects of forest fragmentation on biodiversity have been intensively studied within the remaining forests, relatively little is known about the biodiversity in tropical farmland (Daily et al. 2001, Pimentel et al. 1992). Frugivorous birds are an important group of species in tropical farmland ecosystems. Frugivorous birds are significant seed dispersers and can play a prominent role in transporting seeds into disturbed areas and setting the stage for the regeneration of these systems. Isolated fleshy-fruited trees in agricultural landscapes have been shown to attract birds, leading to an increased seed rain and seedling establishment under their canopies (Carrière et al. 2002, Duncan & Chapman 1999, Guevara et al. 1986, 2004; Slocum & Horvitz 2000).

scholarly journals Emilia coccinea (scarlet tasselflower).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Dominican Republic ◽  
Environmental Conditions ◽  
New Caledonia ◽  
Forest Edges ◽  
Fast Growing ◽  
Disturbed Areas ◽  
Wide Range ◽  
Agricultural Weed ◽  
New Habitats

Abstract As many other species within the genus Emilia, E. coccinea is herb that behaves as an environmental and agricultural weed. This fast-growing herb has the potential to rapidly colonize disturbed areas, waste grounds, gardens, forest edges, pastures, active and abandoned cultivated lands, roadsides, dry thickets and riverbanks. This species is adapted to grow in a wide range of environmental conditions and has wind-dispersed seeds, which are features that may facilitate its spread into new habitats. It is listed as invasive in Hawaii, Dominican Republic and New Caledonia.

Puccinia cynodontis. [Descriptions of Fungi and Bacteria].

1971 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
South Africa ◽  
New Zealand ◽  
Dominican Republic ◽  
Leaf Rust ◽  
Sierra Leone ◽  
Geographical Distribution ◽  
Cynodon Dactylon ◽  
New Caledonia ◽  
New Guinea ◽  
Bermuda Grass

Abstract A description is provided for Puccinia cynodontis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Aecial stage on species of Plantago. Uredial and telial stages on species of Cynodon, particularly C. dactylon. DISEASE: Leaf rust of Bermuda grass (Cynodon dactylon). GEOGRAPHICAL DISTRIBUTION: Widespread. Africa: Ethiopia, Ghana, Kenya, Libya, Malawi, Mauritius Morocco, Nigeria, Sierra Leone, South Africa, Sudan, Tunisia and Zambia. Americas: Argentina, Barbados, Bermuda, Colombia, Dominica, Dominican Republic, Jamaica, Mexico, Nicaragua, Panama, Puerto Rieo, Salvador, Trinidad, USA (South) and Venezuela. Asia: Cambodia, Ceylon, China, India, Iraq, Pakistan, Turkey and USSR. Australasia & Oceania: Australia, Hawaii, New Caledonia, New Zealand and Papua & New Guinea. Europe: Cyprus, France, Malta and Rumania. TRANSMISSION: No studies appear to have been reported. Since the aecial stage has not been found in USA the urediospores presumably survive during the dormant periods of the tdial host.

New records of Cyanobacterial morphotypes with Leptolyngbya indica sp. nov. from terrestrial biofilms of the Lower Gangetic Plain, India

Phytotaxa ◽  
2017 ◽  
Vol 316 (2) ◽  
pp. 101 ◽  
Author(s):  
MANOJIT DEBNATH ◽  
TARKESHWAR SINGH ◽  
PUNYASLOKE BHADURY
Keyword(s):  
Rice Field ◽  
New Records ◽  
Indian Subcontinent ◽  
Culture Conditions ◽  
South East Asia ◽  
Gangetic Plain ◽  
Gangetic Plains ◽  
Rice Field Soil ◽  
Green Remediation ◽  
Mangrove Soils

Macroscopic cyanobacterial biofilms were collected from alluvial plain soils and estuarine mangrove soils representing the Lower Gangetic Plains of South East Asia (India). The composition of the biofilms was investigated using light microscopy and field emission scanning electron microscopy of collected samples. In this study four simple trichal non-heterocytous morphotypes were found to be unique. Out of four, three morphotypes clearly showed differences with respect to described taxa as based on most recent taxonomic classification and possibly represent new report from the Indian subcontinent. One morphotype was successfully established under culture conditions and described as Leptolyngbya indica sp. nov. isolated from the alluvial arsenic affected rice field soil. This study provides vital information on morphotypic diversity of Cyanobacteria from specific biotopes which can contribute key information on their biogeography and potential application in green remediation.

Fire, people and ecosystem change in Pleistocene Australia

2016 ◽  
Vol 64 (8) ◽  
pp. 643 ◽  
Author(s):  
Christopher N. Johnson
Keyword(s):  
Fire Regimes ◽  
Ecosystem Change ◽  
Future Research ◽  
Cascading Effects ◽  
Continental Scale ◽  
The Past ◽  
The 1960S ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

Since the 1960s, Australian scientists have speculated on the impact of human arrival on fire regimes in Australia, and on the relationship of landscape fire to extinction of the Pleistocene megafauna of Australia. These speculations have produced a series of contrasting hypotheses that can now be tested using evidence collected over the past two decades. In the present paper, I summarise those hypotheses and review that evidence. The main conclusions of this are that (1) the effects of people on fire regimes in the Pleistocene were modest at the continental scale, and difficult to distinguish from climatic controls on fire, (2) the arrival of people triggered extinction of Australia’s megafauna, but fire had little or no role in the extinction of those animals, which was probably due primarily to hunting and (3) megafaunal extinction is likely to have caused a cascade of changes that included increased fire, but only in some environments. We do not yet understand what environmental factors controlled the strength and nature of cascading effects of megafaunal extinction. This is an important topic for future research.

scholarly journals 9-year spatial and temporal evolution of desert dust aerosols over South-East Asia as revealed by CALIOP

2017 ◽  
Author(s):  
Emmanouil Proestakis ◽  
Vassilis Amiridis ◽  
Eleni Marinou ◽  
Aristeidis K. Georgoulias ◽  
Stavros Solomos ◽  
...  
Keyword(s):  
East Asia ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Indian Subcontinent ◽  
Dust Aerosol ◽  
Observation Data ◽  
South East Asia ◽  
Desert Dust ◽  
Dust Aerosols ◽  
Se Asia

Abstract. We present a 3-D climatology of the desert dust distribution over South-East Asia derived using CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data. To distinguish desert dust from total aerosol load we apply a methodology developed in the framework of EARLINET (European Aerosol Research Lidar Network), the particle linear depolarization ratio and updated lidar ratio values suitable for Asian dust, on multiyear CALIPSO observations (01/2007–12/2015). The resulting dust product provides information on the horizontal and vertical distribution of dust aerosols over SE (South-East) Asia along with the seasonal transition of dust transport pathways. Persistent high D_AOD (Dust Aerosol Optical Depth) values, of the order of 0.6, are present over the arid and semi-arid desert regions. Dust aerosol transport (range, height and intensity) is subject to high seasonality, with highest values observed during spring for northern China (Taklimakan/Gobi deserts) and during summer over the Indian subcontinent (Thar Desert). Additionally we decompose the CALIPSO AOD (Aerosol Optical Depth) into dust and non-dust aerosol components to reveal the non-dust AOD over the highly industrialized and densely populated regions of SE Asia, where the non-dust aerosols yield AOD values of the order of 0.5. Furthermore, the CALIPSO-based short-term AOD and D_AOD time series and trends between 01/2007 and 12/2015 are calculated over SE Asia and over selected sub-regions. Positive trends are observed over northwest and east China and the Indian subcontinent, whereas over southeast China are mostly negative. The calculated AOD trends agree well with the trends derived from Aqua/MODIS (Moderate Resolution Imaging Spectroradiometer), although significant differences are observed over specific regions.

What was the vegetation in northwest Australia during the Paleogene, 66–23million years ago?

2018 ◽  
Vol 66 (7) ◽  
pp. 556 ◽  
Author(s):  
Michael K. Macphail ◽  
Robert S. Hill
Keyword(s):  
East Asia ◽  
National Park ◽  
Pacific Islands ◽  
New Caledonia ◽  
New Guinea ◽  
First Record ◽  
South East Asia ◽  
North West ◽  
The North ◽  
Dry Conditions

Fossil pollen and spores preserved in drillcore from both the upper South Alligator River (SARV) in the Kakadu National Park, Northern Territory and the North-West Shelf, Western Australia provide the first record of plants and plant communities occupying the coast and adjacent hinterland in north-west Australia during the Paleogene 66 to 23million years ago. The palynologically-dominant woody taxon is Casuarinaceae, a family now comprising four genera of evergreen scleromorphic shrubs and trees native to Australia, New Guinea, South-east Asia and Pacific Islands. Rare taxa include genera now mostly restricted to temperate rainforest in New Guinea, New Caledonia, New Zealand, South-East Asia and/or Tasmania, e.g. Dacrydium, Phyllocladus and the Nothofagus subgenera Brassospora and Fuscospora. These appear to have existed in moist gorges on the Arnhem Land Plateau, Kakadu National Park. No evidence for Laurasian rainforest elements was found. The few taxa that have modern tropical affinities occur in Eocene or older sediments in Australia, e.g. Lygodium, Anacolosa, Elaeagnus, Malpighiaceae and Strasburgeriaceae. We conclude the wind-pollinated Oligocene to possibly Early Miocene vegetation in the upper SARV was Casuarinaceae sclerophyll forest or woodland growing under seasonally dry conditions and related to modern Allocasuarina/Casuarina formations. There are, however, strong floristic links to coastal communities growing under warm to hot, and seasonally to uniformly wet climates in north-west Australia during the Paleocene-Eocene.

scholarly journals Foeniculum vulgare (fennel).

2020 ◽  
Author(s):  
Marianne Jennifer Datiles ◽  
Ian Popay
Keyword(s):  
New Zealand ◽  
Agricultural Land ◽  
Fire Regimes ◽  
Foeniculum Vulgare ◽  
Natural Habitats ◽  
Invasive Weed ◽  
Editorial Committee ◽  
Native Flora ◽  
The Usa ◽  
Environmental Weed

Abstract Foeniculum vulgare, also known as sweet fennel, is a common kitchen herb used around the world - but it is also a highly invasive weed that can severely damage ecosystems. A risk assessment prepared for Hawaii gave the species a high risk score of 19 (PIER, 2015). F. vulgare is known to alter fire regimes and create dense stands, outcompeting native flora for nutrients and space (DiTomaso et al., 2013; Cal-IPC, 2015). It was listed in the Global Compendium of Weeds as an "agricultural weed, casual alien, cultivation escape, environmental weed, garden thug, naturalised, noxious weed, weed" (Randall, 2012), and is known to be invasive (mostly in natural habitats rather than agricultural land) in California, New Zealand, significant parts of Australia and a number of locations in the Pacific. (PIER, 2015). The species is a principal weed in Mexico and New Zealand, a common weed in Argentina, Australia, Hawaii, and Spain, weedy in Chile, Morocco, Uruguay, the USA, and Venezuela, and it is known to be adventive in China, Colombia (Holm et al., 1979; Flora of China Editorial Committee, 2015; PIER, 2015; Vascular Plants of Antioquia, 2015). It is also reported as invasive in Ethiopia and Kenya. It can regenerate by both seeds and roots, which often makes physical control methods ineffective and chemical control necessary once a population is established.

Ganoderma philippii (red root rot).

2020 ◽  
Author(s):  
R. R. M. Paterson
Keyword(s):  
East Asia ◽  
Root Rot ◽  
Woody Plant ◽  
New Caledonia ◽  
South East Asia ◽  
Root Pathogen ◽  
Tropical Plantations ◽  
Combat Climate Change ◽  
Plantation Crops ◽  
Significant Disease

Abstract G. philippii was described as a root pathogen that is particularly destructive to tropical plantation crops, especially rubber (Steyaert, 1975a). It occurs on many woody and non-woody plant hosts in South-East Asia through Indonesia to Papua New Guinea and New Caledonia (UK CAB International, 1993). Acacia trees are considered as invasive species and as an economic crop (Koutika and Richardson, 2019) and the significance of the disease is from both aspects. A similar situation exists for other trees such as Eucalyptus (Deus et al., 2019). These trees are being considered to combat climate change by absorbing carbon dioxide and consequently disease is extremely important. Red root rot is a significant disease of tropical plantations in South-East Asia. In severely infected areas in Malaysia, root rot caused more than 40% mortality of Acacia trees aged between 9 and 14 years. In Indonesia, the disease can kill up to 28% of trees in second-rotation A. mangium plantations in Sumatra and Kalimantan. Second rotation A. mangium and A. crassicarpa plantations trees as young as 6 months old may be killed by red root disease (Gafur et al., 2015).

Dispersal and establishment of slender thistle, Carduus pycnocephalus L. as affected by ground cover

1985 ◽  
Vol 36 (6) ◽  
pp. 791 ◽  
Author(s):  
AR Harradine
Keyword(s):  
Seed Dispersal ◽  
Seedling Establishment ◽  
Ground Cover ◽  
The Other ◽  
Grass Species ◽  
First Year ◽  
Parent Plant ◽  
Annual Grass

After 3 years of spread from sown infestations, slender thistle density in spring was 0.12 and 4.67 plants m-2 for plots in which the ground cover was dominated by cocksfoot and annual grass species, respectively. On plots maintained free of plants other than slender thistle ('bare plots'), the corresponding density was 47.31 plants m-2. Slender thistle seed was dispersed at least 10 m from the parent plant in the first year of seeding and plants were evenly spread over the bare plots after 2 years. After 3 years, slender thistle ingress was still occurring on the other plots. The results indicate the importance of ground cover, either of living plants or of litter, in reducing seedling establishment and seed dispersal of slender thistle.

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