Cymbopogon citratus (lemongrass).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Chromosome Number ◽  
Life Span ◽  
Clay Soils ◽  
Annual Rainfall ◽  
Saline Soils ◽  
Cymbopogon Citratus ◽  
Mean Annual Rainfall ◽  
Flora Of China ◽  
Environmental Requirements

Abstract Genetics: The chromosome number reported for C. citratus is 2n = 40 (Flora of China, 2016). Reproductive biologyIn most places Cymbopogon citratus flowers very rarely or not at all. It mostly reproduces vegetatively (Oyen, 1999). Physiology and phenology: In China, C. citratus has been recorded flowering and fruiting during summer (Flora of China, 2016). Longevity: Cymbopogon citratus has a life-span of 4-6 years (Oyen, 1999). Environmental requirements: Cymbopogon citratus grows best under sunny, warm and humid conditions at elevations below 750 m, with mean annual temperatures ranging from 23°C to 30°C and mean annual rainfall between 2500-3000 mm. It is adapted to grow on a wide variety of soils types, but prefers well-drained soils with pH ranging from 5.5 to 7.5. However, this species has been recorded growing in Australia on clay soils with pH=9.6. It does not tolerate saline soils or frosty conditions (Oyen, 1999).

scholarly journals Quantification of southwest China rainfall during the 8.2 ka BP event with response to North Atlantic cooling

2016 ◽  
Vol 12 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
Yuhui Liu ◽  
Chaoyong Hu
Keyword(s):  
High Resolution ◽  
Southwest China ◽  
East Asian Monsoon ◽  
Moving Average ◽  
Ice Core ◽  
Scale Model ◽  
Annual Rainfall ◽  
Transport Pathway ◽  
Mean Annual Rainfall ◽  
Monsoon Area

Abstract. The 8.2 ka BP event could provide important information for predicting abrupt climate change in the future. Although published records show that the East Asian monsoon area responded to the 8.2 ka BP event, there is no high-resolution quantitative reconstructed climate record in this area. In this study, a reconstructed 10-year moving average annual rainfall record in southwest China during the 8.2 ka BP event is presented by comparing two high-resolution stalagmite δ18O records from Dongge cave and Heshang cave. This decade-scale rainfall reconstruction is based on a central-scale model and is confirmed by inter-annual monitoring records, which show a significant positive correlation between the regional mean annual rainfall and the drip water annual average δ18O difference from two caves along the same monsoon moisture transport pathway from May 2011 to April 2014. Similar trends between the reconstructed rainfall and the stalagmite Mg ∕ Ca record, another proxy of rainfall, during the 8.2 ka BP period further increase the confidence of the quantification of the rainfall record. The reconstructed record shows that the mean annual rainfall in southwest China during the central 8.2 ka BP event is less than that of present (1950–1990) by  ∼  200 mm and decreased by  ∼  350 mm in  ∼  70 years experiencing an extreme drying period lasting for  ∼  50 years. Comparison of the reconstructed rainfall record in southwest China with Greenland ice core δ18O and δ15N records suggests that the reduced rainfall in southwest China during the 8.2 ka BP period was coupled with Greenland cooling with a possible response rate of 110 ± 30 mm °C−1.

scholarly journals Modelling monthly runoff generation processes following land use changes: groundwater–surface runoff interactions

2004 ◽  
Vol 8 (5) ◽  
pp. 903-922 ◽  
Author(s):  
M. Bari ◽  
K. R. J. Smettem
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Surface Runoff ◽  
Land Use Changes ◽  
Annual Rainfall ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Mean Annual Rainfall ◽  
Monthly Runoff ◽  
Stream Bed

Abstract. A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall–runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, "Ernies" (control, fully forested) and "Lemon" (54% cleared) are in a zone of mean annual rainfall of 725 mm, while "Salmon" (control, fully forested) and "Wights" (100% cleared) are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall–runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i) an upper zone unsaturated store, (ii) a transient stream zone store, (ii) a lower zone unsaturated store and (iv) a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and predicted monthly hydrographs. The observed and predicted monthly runoff for all catchments matched well with coefficients of determination (R2) ranging from 0.68 to 0.87. Predictions were relatively poor for: (i) the Ernies catchment (lowest rainfall, forested), and (ii) months with very high flows. Overall, the predicted mean annual streamflow was within ±8% of the observed values. Keywords: monthly streamflow, land use change, conceptual model, data-based approach, groundwater

scholarly journals Precipitation as driver of carbon fluxes in 11 African ecosystems

2008 ◽  
Vol 5 (5) ◽  
pp. 4071-4105 ◽  
Author(s):  
L. Merbold ◽  
J. Ardö ◽  
A. Arneth ◽  
R. J. Scholes ◽  
Y. Nouvellon ◽  
...  
Keyword(s):  
Land Surface ◽  
Ecosystem Respiration ◽  
Carbon Assimilation ◽  
Vapour Pressure Deficit ◽  
Sub Saharan Africa ◽  
Annual Rainfall ◽  
C3 Plants ◽  
Water Vapour Pressure ◽  
Mean Annual Rainfall ◽  
Sub Saharan

Abstract. This study reports carbon and water fluxes between the land surface and atmosphere in eleven different ecosystems types in Sub-Saharan Africa, as measured using eddy covariance (EC) technology in the first two years of the CarboAfrica network operation. The ecosystems for which data were available ranged in mean annual rainfall from 320 mm (Sudan) to 1150 mm (The Republic of Congo) and include a spectrum of vegetation types (or land cover) (open savannas, woodlands, croplands and grasslands). Given the shortness of the record, the EC data were analysed across the network rather than longitudinally at sites, in order to understand the driving factors for ecosystem respiration and carbon assimilation, and to reveal the different water use strategies in these highly seasonal environments. Values for maximum net carbon assimilation rates (photosynthesis) ranged from 12 μmol CO2 m−2 s−1 in a dry, open Acacia savanna (C3-plants) up to 40 μmol CO2 m−2 s−1 for a tropical moist grassland. Maximum carbon assimilation rates were highly correlated with mean annual rainfall (R2=0.89). Maximum photosynthetic uptake rates were positively related to satellite-derived fAPAR. Ecosystem respiration was dependent on temperature at all sites, and was additionally dependent on soil water content at sites receiving less than 1000 mm of rain per year. All included ecosystems, except the Congolese grassland, showed a strong decrease in 30-min assimilation rates with increasing water vapour pressure deficit above 2.0 kPa.

Geo-statistical modeling of mean annual rainfall over the Iran using ECMWF database

2017 ◽  
Vol 25 (2) ◽  
pp. 219-227 ◽  
Author(s):  
Robab Razmi ◽  
Saeed Balyani ◽  
Mohammad Reza Mansouri Daneshvar
Keyword(s):  
Statistical Modeling ◽  
Annual Rainfall ◽  
Mean Annual Rainfall

LATE HOLOCENE FIRE AND AGRICULTURE IN THE COPAN VALLEY, HONDURAS

2002 ◽  
Vol 13 (2) ◽  
pp. 267-272 ◽  
Author(s):  
David Rue ◽  
David Webster ◽  
Alfred Traverse
Keyword(s):  
Forest Fires ◽  
Late Holocene ◽  
Fire History ◽  
Annual Rainfall ◽  
Charcoal Analysis ◽  
Maya Lowlands ◽  
The Core ◽  
Mean Annual Rainfall ◽  
Copan Valley ◽  
Agricultural Trends

Pollen and charcoal analysis of a 5.3-m sediment core from Aguada Petapilla, a peat bog, provides evidence of late Holocene vegetation and fire history in the Copan Valley, Honduras. Low concentration and preservation problems characterized the pollen flora, but there are taxa present indicative of major agricultural trends, including Zea mays. Microscopic charcoal fragments are well represented and record continued burning in the region since the lowest level of the core (5700 B.P. [3750 B.C.]). Presence of Zea indicates that maize farming was initiated by as early as 2300 B.C. Three peaks in charcoal-fragment frequencies occur in periods centered approximately at 900 B.C., 400 B.C., and A.D. 600. Fires in this relatively dry region of the southern Maya Lowlands (whose mean annual rainfall is about 1,400 mm) could have resulted from natural forest fires or human agricultural clearing at any time in the Holocene. This contrasts with wetter areas of tropical Central and South America (mean annual rainfall of about 2,500–4,000 mm) where significant climatic drying is required to ignite primary tropical forest.

A Practical Method for Estimating Rainfall Rate Frequencies Directly from Climatic Data

1958 ◽  
Vol 39 (9) ◽  
pp. 469-472 ◽  
Author(s):  
S. L. Russak ◽  
J. W. Easley
Keyword(s):  
Signal Transmission ◽  
General Relation ◽  
Practical Method ◽  
Rainfall Rate ◽  
Annual Rainfall ◽  
Climatic Data ◽  
Mean Annual Rainfall ◽  
Hourly Rainfall ◽  
The Mean ◽  
Complete Frequency

In evaluating the environmental limitations on microwave signal transmission, it was necessary to determine the occurrence of rainfall rates for a number of regions in different parts of the world. Clock-hourly precipitation data were used where available. Where these data were not available, a known empirical technique was employed which correlates clock-hourly rainfall at individual rates to a climatological index. This index uses parameters which are almost universally obtainable—namely, mean annual rainfall and number of days with measurable rain. In the course of this work, the authors found a more general relation between clock-hourly rainfall rate frequencies and the climatological index. Using this relation, rainfall frequencies at any rate are obtained directly from a linear equation and two nomograms. It is also possible to synthesize the complete frequency distribution of rainfall rates and obtain, as a check, the mean annual rainfall. Examples, supplemented by illustrations, are given in the development of this technique and its utilization.

Parent material and climate affect soil organic carbon fractions under pastures in south-eastern Australia

Soil Research ◽  
2017 ◽  
Vol 55 (8) ◽  
pp. 799 ◽  
Author(s):  
Susan E. Orgill ◽  
Jason R. Condon ◽  
Mark K. Conyers ◽  
Stephen G. Morris ◽  
Brian W. Murphy ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Parent Material ◽  
Climatic Zone ◽  
Annual Rainfall ◽  
Carbon Fractions ◽  
South Eastern ◽  
Mean Annual Rainfall ◽  
Eastern Australia ◽  
South Eastern Australia

In the present field survey, 72 sites were sampled to assess the effect of climate (Monaro, Boorowa and Coleambally regions) and parent material (Monaro region only; basalt and granite) on soil organic carbon (OC) under perennial pastures. In the higher-rainfall zone (Monaro and Boorowa; >500mm mean annual rainfall), OC stocks under introduced and native perennial pastures were compared, whereas in the lower-rainfall zone (Coleambally; <500mm mean annual rainfall) OC stocks under crops and pastures were compared. Carbon fractions included total OC (TOC), particulate OC (POC), resistant OC (ROC) and humic OC (HUM). Higher OC stocks were associated with higher spring and summer rainfall and lower annual temperatures. Within a climatic zone, parent material affected the stock of OC fractions in the 0–30cm soil layer. Within a climatic zone, when grouped by parent material, there was no difference in OC stock with vegetation type. There were significant correlations between soil factors associated with parent material and OC concentration, including negative correlations between SiO2 and HUM (P<0.05) and positive correlations between cation exchange capacity and TOC, POC and ROC (P<0.01). TOC was also positively correlated with total nitrogen (N) and available sulfur (S; P<0.05), indicating organic matter in soil is important for N and S supply for plant production in the studied regions, and vice versa. Although ensuring adequate available S may increase OC stocks in south-eastern Australia, the large stock of OC in the soil under perennial pastures, and the dominating effect of climate and parent material on this stock, may mean that modest increases in soil OC due to management factors go undetected.

A review of the use of phosphate rocks as fertilizers for direct application in Australia and New Zealand.

1990 ◽  
Vol 30 (2) ◽  
pp. 297 ◽  
Author(s):  
NS Bolan ◽  
RE White ◽  
MJ Hedley
Keyword(s):  
North Carolina ◽  
New Zealand ◽  
Soil Ph ◽  
Western Australia ◽  
Chemical Reactivity ◽  
Field Trials ◽  
Annual Rainfall ◽  
Phosphate Rocks ◽  
Mean Annual Rainfall ◽  
Suitable Area

Field trials in New Zealand have shown that reactive phosphate rocks (RPRs) can be as effective as soluble P fertilisers, per kg of P applied, on permanent pastures that have a soil pH<6.0 (in water) and a mean annual rainfall >800 mm. Whereas RPRs such as North Carolina, Sechura, Gafsa and Chatham Rise have been evaluated on permanent pastures in New Zealand, most Australian field trials have examined unreactive PRs such as Christmas Island A and C grade, Nauru and Duchess, using annual plant species. Only in recent experiments has an RPR, North Carolina, been examined. Except on the highly leached sands in southern and south-western Australia, both reactive and unreactive PRs have shown a low effectiveness relative to superphosphate. In addition to chemical reactivity, other factors may contribute to the difference in the observed agronomic effectiveness of PRs in Australia and New Zealand. Generally, PRs have been evaluated on soils of lower pH, higher pH buffering capacity (as measured by titratable acidity) and higher P status in New Zealand than in Australia. Rainfall is more evenly distributed throughout the year on New Zealand pastures than in Australia where the soil surface dries out between rainfall events. Dry conditions reduce the rate at which soil acid diffuses to a PR granule and dissolution products diffuse away. Even when pH and soil moisture are favourable, the release of P from PR is slow and more suited to permanent pasture (i.e. the conditions usually used to evaluate PRs in New Zealand) than to the annual pastures or crops used in most Australian trials. Based on the criteria of soil pH<6.0 and mean annual rainfall >800 mm, it is estimated that the potentially suitable area for RPRs on pasture in New Zealand is about 8 million ha. Extending this analysis to Australia, but excluding the seasonal rainfall areas of northern and south-western Australia, the potentially suitable area is about 13 million ha. In New Zealand, many of the soils in the North and South Islands satisfy both the pH and rainfall criteria. However, suitable areas in Australia are confined mainly to the coastal and tableland areas of New South Wales and eastern Victoria, and within these areas the actual effectiveness of RPR will depend markedly on soil management and the distribution of annual rainfall. Further research on RPR use should be focused on these areas.

THE MEAN ANNUAL RAINFALL OF MOUNT KENYA

Weather ◽  
1966 ◽  
Vol 21 (2) ◽  
pp. 48-49 ◽  
Author(s):  
B. W. Thompson
Keyword(s):  
Annual Rainfall ◽  
Mean Annual Rainfall ◽  
The Mean
Sign in / Sign up

Export Citation Format

Share Document