Phytogeography and climate analysis of Nothofagus subgenus Brassospora in New Guinea and New Caledonia

2005 ◽  
Vol 53 (4) ◽  
pp. 297 ◽  
Author(s):  
Jennifer Read ◽  
Geoffrey S. Hope ◽  
Robert S. Hill
Keyword(s):  
New Caledonia ◽  
New Guinea ◽  
Niche Differentiation ◽  
Annual Precipitation ◽  
Wet Season ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Extant Species ◽  
Significant Difference ◽  
Climate Analysis

Nothofagus subgenus Brassospora now occurs only in New Guinea and New Caledonia, but is well known from fossil deposits of South America, New Zealand, Antarctica and Australia. It is commonly used for palaeoclimatic interpretation, but the climate characteristics of the extant species have not been described. In this paper we used the climatic estimation software, BIOCLIM, to derive a climate profile of 24 variables for each of the 14 species of Nothofagus native to New Guinea, and lapse rates and isohyet maps to describe the annual mean temperature and rainfall range of the five species native to New Caledonia. The New Guinea species occur at annual mean temperatures ranging from 10.6 to 23.5°C, with annual precipitation of 1762–7733 mm. The first three axes of a principal components analysis explained 85% of the total variation, the first axis comprising temperature variables, the second comprising precipitation range and precipitation of the wet season, and the third axis comprising dry-season precipitation and annual and diurnal temperature range. Some species had distinct combinations of positions along these component axes, indicating clear niche differentiation with respect to climate. The New Caledonian species occur at annual mean temperatures of 14.5–23.5°C, and annual precipitation of c. 1500–3500 mm. Although there was no significant difference in annual mean temperature and precipitation between the New Guinea and New Caledonian species, comparison of median values across species suggests specialisation of most New Caledonian species towards slightly drier conditions than the New Guinea species that occur at similarly high annual mean temperatures. Use of subgenus Brassospora to interpret palaeoclimates should take into account the variation in climate experienced across the range of extant species.

scholarly journals Observed and Projected Changes in Temperature and Precipitation in the Core Crop Region of the Humid Pampa, Argentina

Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 40
Author(s):  
Gabriela V. Müller ◽  
Miguel A. Lovino ◽  
Leandro C. Sgroi
Keyword(s):  
Climate Extremes ◽  
Annual Precipitation ◽  
Climate Conditions ◽  
The Core ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Maximum Temperatures ◽  
Projected Changes ◽  
Precipitation Changes ◽  
Precipitation Events

The core crop region of the Humid Pampa is one of the most productive agricultural lands around the world and depends highly on climate conditions. This study assesses climate variability, climate extremes, and observed and projected climate changes there, using 1911–2019 observations and CMIP5 model simulations. Since 1970, the annual mean temperature has risen by 1 °C and the mean annual minimum and maximum temperatures by 2 and 0.5 °C, respectively. The frequency of warm days and nights increased, and cold days and nights decreased. Heatwaves became longer and more intense, and cold waves decreased with less frost events. Annual precipitation increased by 10% from 1911, mainly in summer, and years with excess precipitation outnumbered those with a deficit. Both intense precipitation events and consecutive dry days grew, suggesting more annual precipitation falling on fewer days. Projections show a warming of 1 °C by 2035, regardless of the scenario. From then on until 2100, mean temperature will increase by 2 and 3–3.5 °C in the RCP4.5 and RCP8.5 scenarios, respectively. Annual precipitation will grow 8 and 16% from current values by 2100 in the RCP4.5 and RCP8.5 scenarios, respectively. No major precipitation changes are projected in the RCP2.6 scenario.

scholarly journals Possible Scenarios of Winter Wheat Yield Reduction of Dryland Qazvin Province, Iran, Based on Prediction of Temperature and Precipitation Till the End of the Century

Climate ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 78 ◽  
Author(s):  
Behnam Mirgol ◽  
Meisam Nazari
Keyword(s):  
Winter Wheat ◽  
Crop Yields ◽  
Wheat Yield ◽  
Annual Precipitation ◽  
Yield Reduction ◽  
Factors Affecting ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Winter Wheat Yield ◽  
Semi Arid

The climate of the Earth is changing. The Earth’s temperature is projected to maintain its upward trend in the next few decades. Temperature and precipitation are two very important factors affecting crop yields, especially in arid and semi-arid regions. There is a need for future climate predictions to protect vulnerable sectors like agriculture in drylands. In this study, the downscaling of two important climatic variables—temperature and precipitation—was done by the CanESM2 and HadCM3 models under five different scenarios for the semi-arid province of Qazvin, located in Iran. The most efficient scenario was selected to predict the dryland winter wheat yield of the province for the three periods: 2010–2039, 2040–2069, and 2070–2099. The results showed that the models are able to satisfactorily predict the daily mean temperature and annual precipitation for the three mentioned periods. Generally, the daily mean temperature and annual precipitation tended to decrease in these periods when compared to the current reference values. However, the scenarios rcp2.6 and B2, respectively, predicted that the precipitation will fall less or even increase in the period 2070–2099. The scenario rcp2.6 seemed to be the most efficient to predict the dryland winter wheat yield of the province for the next few decades. The grain yield is projected to drop considerably over the three periods, especially in the last period, mainly due to the reduction in precipitation in March. This leads us to devise some adaptive strategies to prevent the detrimental impacts of climate change on the dryland winter wheat yield of the province.

scholarly journals Contrasting Evolution Patterns of Endorheic and Exorheic Lakes on the Central Tibetan Plateau and Climate Cause Analysis during 1988–2017

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1962
Author(s):  
Zhilong Zhao ◽  
Yue Zhang ◽  
Zengzeng Hu ◽  
Xuanhua Nie
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Climatic Factors ◽  
Global Climate ◽  
Rapid Expansion ◽  
Annual Precipitation ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Climate Change Research ◽  
Mean Temperature

The alpine lakes on the Tibetan Plateau (TP) are indicators of climate change. The assessment of lake dynamics on the TP is an important component of global climate change research. With a focus on lakes in the 33° N zone of the central TP, this study investigates the temporal evolution patterns of the lake areas of different types of lakes, i.e., non-glacier-fed endorheic lakes and non-glacier-fed exorheic lakes, during 1988–2017, and examines their relationship with changes in climatic factors. From 1988 to 2017, two endorheic lakes (Lake Yagenco and Lake Zhamcomaqiong) in the study area expanded significantly, i.e., by more than 50%. Over the same period, two exorheic lakes within the study area also exhibited spatio-temporal variability: Lake Gaeencuonama increased by 5.48%, and the change in Lake Zhamuco was not significant. The 2000s was a period of rapid expansion of both the closed lakes (endorheic lakes) and open lakes (exorheic lakes) in the study area. However, the endorheic lakes maintained the increase in lake area after the period of rapid expansion, while the exorheic lakes decreased after significant expansion. During 1988–2017, the annual mean temperature significantly increased at a rate of 0.04 °C/a, while the annual precipitation slightly increased at a rate of 2.23 mm/a. Furthermore, the annual precipitation significantly increased at a rate of 14.28 mm/a during 1995–2008. The results of this study demonstrate that the change in precipitation was responsible for the observed changes in the lake areas of the two exorheic lakes within the study area, while the changes in the lake areas of the two endorheic lakes were more sensitive to the annual mean temperature between 1988 and 2017. Given the importance of lakes to the TP, these are not trivial issues, and we now need accelerated research based on long-term and continuous remote sensing data.

scholarly journals Analysis of livestock breeders’ perceptions and their adaptation measures to climate change in Morocco‘s arid rangelands

2020 ◽  
Vol 6 (1) ◽  
pp. 1-25
Author(s):  
Wadii Snaibi
Keyword(s):  
Climate Change ◽  
Local Level ◽  
Small Scale ◽  
Climate Data ◽  
Chi Square ◽  
Adaptation Measures ◽  
Significant Difference ◽  
The Difference ◽  
Eastern Morocco ◽  
Climate Analysis

AbstractThe high plateaus of eastern Morocco are already suffering from the adverse impacts of climate change (CC), as the local populations’ livelihoods depend mainly on extensive sheep farming and therefore on natural resources. This research identifies breeders’ perceptions about CC, examines whether they correspond to the recorded climate data and analyses endogenous adaptation practices taking into account the agroecological characteristics of the studied sites and the difference between breeders’ categories based on the size of owned sheep herd. Data on perceptions and adaptation were analyzed using the Chi-square independence and Kruskal-Wallis tests. Climate data were investigated through Mann-Kendall, Pettitt and Buishand tests.Herders’ perceptions are in line with the climate analysis in term of nature and direction of observed climate variations (downward trend in rainfall and upward in temperature). In addition, there is a significant difference in the adoption frequency of adaptive strategies between the studied agroecological sub-zones (χ2 = 14.525, p <.05) due to their contrasting biophysical and socioeconomic conditions, as well as among breeders’ categories (χ2 = 10.568, p < .05) which attributed mainly to the size of sheep flock. Policy options aimed to enhance local-level adaptation should formulate site-specific adaptation programs and prioritise the small-scale herders.

Dysdercus sidae. [Distribution map].

1970 ◽  
Author(s):  
Keyword(s):  
Geographical Distribution ◽  
Host Plants ◽  
Pacific Islands ◽  
New Caledonia ◽  
Solomon Islands ◽  
New Guinea ◽  
Distribution Map ◽  
Irian Jaya ◽  
New Hebrides ◽  
New Distribution

Abstract A new distribution map is provided for Dysdercus sidae Montr. (D. insular is Stål) (Hemipt., Pyrrhocoridae). Host Plants: Cotton, kapok, Hibiscus spp. Information is given on the geographical distribution in AUSTRALASIA AND PACIFIC ISLANDS, Australia, Fiji, Loyalty Islands, New Caledonia, New Hebrides, Niue, Papua & New Guinea, Samoa, Solomon Islands, Tonga, Wallis Islands, Irian Jaya.

Comparative Analysis or Precipitation Variation Characteristics between Subtropical Monsoon Climate and Temperate Monsoon Climate-Take Changsha and Chengde for Example

2021 ◽  
Vol 7 (5) ◽  
pp. 1113-1122
Author(s):  
Bo Chen ◽  
Shi-jun Xu ◽  
Xin-ping Zhang ◽  
Yi Xie
Keyword(s):  
Climate Change ◽  
Extreme Precipitation ◽  
Precipitation Intensity ◽  
Annual Precipitation ◽  
Wet Season ◽  
Precipitation Frequency ◽  
Extreme Precipitation Events ◽  
Average Precipitation ◽  
Autumn And Winter ◽  
Average Annual Precipitation

Using the methods of literature review, regression analysis and moving average, this paper selects the daily precipitation of Changsha and Chengde from 1951 to 1986 as samples, and analyzes the average precipitation, precipitation frequency, precipitation intensity, extreme precipitation time and other indicators of Changsha and Chengde from the perspective of interannual and seasonal changes Trends. The researches show that: the average precipitation of Changsha in the 36 years is 1151.2mm, spring is the wet season, autumn and winter are the dry seasons, and the maximum average precipitation is in spring; the average annual precipitation, precipitation frequency in spring, summer and winter, annual precipitation frequency, annual precipitation intensity and extreme precipitation events show a decreasing trend. The average annual precipitation of Chengde city is 454.1 mm, wet season in summer and dry season in spring, autumn and winter; the average annual precipitation, precipitation in four seasons, annual precipitation frequency, precipitation frequency in spring, autumn and winter, annual precipitation intensity and extreme precipitation events show a decreasing trend, while the precipitation frequency in summer shows an increasing trend. The study of regional climate change based on the time series data of this stage is of great significance to comprehensively understand the law of regional climate change and predict the future trend of climate change.

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.

The Decolonisation of the Pacific Islands

Itinerario ◽  
2000 ◽  
Vol 24 (3-4) ◽  
pp. 173-191 ◽  
Author(s):  
Robert Aldrich
Keyword(s):  
New Zealand ◽  
Pacific Islands ◽  
New Caledonia ◽  
Solomon Islands ◽  
New Guinea ◽  
The United States ◽  
French Polynesia ◽  
American Samoa ◽  
Caroline Islands ◽  
Foreign Control

At the end of the Second World War, the islands of Polynesia, Melanesia and Micronesia were all under foreign control. The Netherlands retained West New Guinea even while control of the rest of the Dutch East Indies slipped away, while on the other side of the South Pacific, Chile held Easter Island. Pitcairn, the Gilbert and Ellice Islands, Fiji and the Solomon Islands comprised Britain's Oceanic empire, in addition to informal overlordship of Tonga. France claimed New Caledonia, the French Establishments in Oceania (soon renamed French Polynesia) and Wallis and Futuna. The New Hebrides remained an Anglo-French condominium; Britain, Australia and New Zealand jointly administered Nauru. The United States' territories included older possessions – the Hawaiian islands, American Samoa and Guam – and the former Japanese colonies of the Northern Marianas, Mar-shall Islands and Caroline Islands administered as a United Nations trust territory. Australia controlled Papua and New Guinea (PNG), as well as islands in the Torres Strait and Norfolk Island; New Zealand had Western Samoa, the Cook Islands, Niue and Tokelau. No island group in Oceania, other than New Zealand, was independent.

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 Reaction Kinetics of Iron Oxides in Ok Tedi Magnetite Skarn Ore

2020 ◽  
pp. 1-13
Author(s):  
Mary Kama ◽  
Kaul Gena ◽  
Tindi Seje Nuru
Keyword(s):  
Reaction Kinetics ◽  
Papua New Guinea ◽  
Iron Reduction ◽  
New Guinea ◽  
Reaction Rate Constant ◽  
Close Monitoring ◽  
Significant Difference ◽  
Different Temperatures ◽  
C 30 ◽  
Kinetics Of

Magnetic skarn ore (MSO) is one of the major copper bearing ore extracted by the Ok Tedi Copper Mine in Papua New Guinea (PNG). Copper minerals are recovered by flotation while the iron not associated with copper are discarded as tailings. The objective of this investigation was to determine the iron ore reduction kinetics for the Ok Tedi MSO and ascertain if it can be processed to produce sponge iron for a mini steel plant in Papua New Guinea. SEM-EDAX analyses of the Ok Tedi MSO indicated 10.1% C, 30% O, 0.6% Mg, 1.1% Si, 21.1% S, 0.8% Ca and 36.2 % Fe. Most of the iron is in sulfide form. Both naturally occurring and roasted sinters of Ok Tedi MSO samples of different particle sizes were reduced by charcoal carbon at three different temperatures and seven different reduction times. Analyses of the reduced products indicated a metallic iron content of more than 65 wt. % on average. Results showed that there was no significant difference in reduction between fluxed and control materials. Only a slight increase in kinetics with reduced particle size, hence the reaction rate constant (K) did not vary much within the temperatures investigated. Reaction kinetics increases with increasing reduction time at 900°C. Therefore, more iron reduction is observed with particles of 106 µm size. In addition, the results also confirmed that the reduction energy used was higher at 800°C and lower at 1000°C. In conclusion, iron reduction can be improved but close monitoring of temperature and reduction times are essential to determine the reaction kinetics of the Ok Tedi MSO.

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