Journal articles: 'Semi-arid zone'

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Jawad, Thaer K., Osama T. Al-Taai, and Yaseen K. Al-timimi. "Evaluation of Drought Characteristics in Iraq using SC-PDSI." Science Journal of University of Zakho 6, no. 3 (September 30, 2018): 94–99. http://dx.doi.org/10.25271/sjuoz.2018.6.3.511.

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Evaluation of drought characteristics in Iraq by analysis annual growing season of Self-Calibrating Palmer Drought Severity Index (SC-PDSI) for three climatic zones using run theory method. The efficiency of SC-PDSI for drought monitoring was examined from compared with Rainfall Departure from the mean (RD) for three zones (Arid and Semi-Arid, Steppes and Desert) for the period 1981-2015, were derived from Climatic Research Unit (CRU). The spatial interpolation techniques in ArcGIS package has been used, to cover the whole extent of country and extracting the zones. Statistical methods were applied to compute the probability of drought events at every zone. The results showed the years 1999, 2000, 2008 and 2009 experienced droughts in all zones except the desert zone where was experienced severe drought in 2012, while the years 1982 and 1988 experienced received precipitation above-average in all zones. The values of standard deviation of precipitation were compared with precipitation anomalies for each zone, the drier seasons are (2007-2008) and (1998-1999) in all Zones. The wetter seasons are (1987-1988) in Arid and Semi-Arid and Steppes zone, (1994-1995) and (1997-1998) are wetter seasons in Desert zone. Using run theory, the steppes zone have experienced more severe droughts than other zones evaluated in this study and the most susceptible areas to dry spell are steppes and Arid and Semi-Arid Zones during study period. While the desert zone experienced less droughts.

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Jawad, Thaer K., Osama T. Al-Taai, and Yaseen K. Al-Timimi. "Evaluation of Drought Characteristics in Iraq using SC-PDSI." Science Journal of University of Zakho 6, no. 4 (December 30, 2018): 177–82. http://dx.doi.org/10.25271/sjuoz.2018.6.4.547.

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Evaluation of drought characteristics in Iraq by analysis annual growing season of Self-Calibrating Palmer Drought Severity Index (SC-PDSI) for three climatic zones using run theory method. The efficiency of SC-PDSI for drought monitoring was examined from compared with Rainfall Departure from the mean (RD) for three zones (Arid and Semi-Arid, Steppes and Desert) for the period 1981-2015, were derived from Climatic Research Unit (CRU). The spatial interpolation techniques in ArcGIS package has been used, to cover the whole extent of country and extracting the zones. Statistical methods were applied to compute the probability of drought events at every zone. The results showed the years 1999, 2000, 2008 and 2009 experienced droughts in all zones except the desert zone where was experienced severe drought in 2012, while the years 1982 and 1988 experienced received precipitation above-average in all zones. The values of standard deviation of precipitation were compared with precipitation anomalies for each zone, the drier seasons are (2007-2008) and (1998-1999) in all Zones. The wetter seasons are (1987-1988) in Arid and Semi-Arid and Steppes zone, (1994-1995) and (1997-1998) are wetter seasons in Desert zone. Using run theory, the steppes zone have experienced more severe droughts than other zones evaluated in this study and the most susceptible areas to dry spell are steppes and Arid and Semi-Arid Zones during study period. While the desert zone experienced less droughts.

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KOBATAKE, Shigeki, and M. O. NYADAWA. "Runoff Characteristics in semi-Arid Zone." PROCEEDINGS OF HYDRAULIC ENGINEERING 41 (1997): 215–20. http://dx.doi.org/10.2208/prohe.41.215.

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Paul, Ranjit Kumar, and P. S. Birthal. "Investigating rainfall trend over India using the wavelet technique." Journal of Water and Climate Change 7, no. 2 (November 4, 2015): 353–64. http://dx.doi.org/10.2166/wcc.2015.079.

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In this paper, using the wavelet technique we analysed rainfall behaviour in the country across different agro-climatic zones over a century. Findings indicate that at the national level there is no significant trend in rainfall in the long run, but there are pockets of change in the rainfall pattern. There was a significant increase in the rainfall in the arid zone, whereas in the humid, semi-arid tropics and semi-arid temperate zones the trend was downward but insignificant. The behaviour of rainfall was different during this period. Except in the arid zone, we find a similar trend in other zones – increasing initially, tapering off in the middle and then declining but with some difference in time intervals. In the arid zone, the behaviour of rainfall had been erratic. In the short run, the direction of change in trend remains the same as in the long run but the change is statistically significant.

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Musa, Abuelgasim I. I., Mitsuru Tsubo, Shaoxiu Ma, Yasunori Kurosaki, Yasuomi Ibaraki, and Imad-Eldin A. Ali-Babiker. "Evaluation of WRF Cumulus Parameterization Schemes for the Hot Climate of Sudan Emphasizing Crop Growing Seasons." Atmosphere 13, no. 4 (April 2, 2022): 572. http://dx.doi.org/10.3390/atmos13040572.

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High spatiotemporal resolution climate data are essential for climate-related impact studies. The Weather Research and Forecasting (WRF) model is widely used to downscale climate data for different regions with regional-specific physics configurations. This study aimed to identify robust configurations of the WRF model, especially cumulus parameterization schemes, for different climatic zones of Sudan. We focused on wet season (June–September) rainfall and dry season (November–February) temperature, which are determinants of summer crop and irrigated wheat yields, respectively. Downscaling experiments were carried out to compare the following schemes: Betts–Miller–Janjic (BMJ), improved Kain–Fritch (KFT), modified Tiedtke (TDK), and Grell–Freitas (GF). Results revealed that the BMJ performed better for wet season rainfall in the hyper-arid and arid zones; KFT performed better for rainfall in July and August in the semi-arid zone where most summer crops are cultivated. For dry season temperature, the BMJ and TDK outperformed the other schemes in all three zones, except that the GF performed best for the minimum temperature in December and January in the arid zone, where irrigated wheat is produced, and in the semi-arid zone. Specific parameterization schemes therefore need to be selected for specific seasons and climatic zones of Sudan.

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Palmer, Carol. "Ethnobotanical investigation of semi-arid zone crop husbandry." Levant 23, no. 1 (January 1, 1991): 3. http://dx.doi.org/10.1179/007589191790212360.

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de la Paix Mupenzi, Jean, Lanhai Li, Jiwen Ge, Jean Ngamije, Verenyam Achal, Gabriel Habiyaremye, and Jean de Dieu Habumugisha. "Water losses in arid and semi-arid zone: Evaporation, evapotranspiration and seepage." Journal of Mountain Science 9, no. 2 (March 21, 2012): 256–61. http://dx.doi.org/10.1007/s11629-012-2186-z.

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H. HAFTOM, A. HAFTU, K. GOITOM, and H. MESERET. "Agroclimatic zonation of Tigray region of Ethiopia based on aridity index and traditional agro-climatic zones." Journal of Agrometeorology 21, no. 2 (November 10, 2021): 176–81. http://dx.doi.org/10.54386/jam.v21i2.229.

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The aim of this study was to identify the agroclimatic zones of Tigray region based on aridity index and traditional agroclimatic zone using 37-year (1981-2017) spatial climate data downloaded for Tigray region from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) for rainfall and from Enhancing National Climate Services (ENACTS) data for temperature. Arc map 10.3 was used for mapping of all climatic variables and zonation of agro-climatic zones. Potential evapotranspiration (PET) was computed based on Hargreaves formula and the aridity index was computed. Besides, the digital elevation model was downloaded from ASTER data. The aridity map of Tigray divided into three index zones (0.03-0.2, 0.2–0.5 and 0.5–0.65) and five traditional agro-climate zones (<1500,1500-2000,2000- 2500, 2500-3000, >3000 m.a.s.l.) were overlaid, which divided entire region of Tigray into fifteen agroclimatic zones. Hot semi-arid, warm semi-arid, tepid semi-arid and hot arid were the dominant zones in the region.

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Zhu, Ping, Wei Cao, Lin Huang, Tong Xiao, and Jun Zhai. "The Impacts of Human Activities on Ecosystems within China’s Nature Reserves." Sustainability 11, no. 23 (November 23, 2019): 6629. http://dx.doi.org/10.3390/su11236629.

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Protected areas (PAs) provide refuges for threatened species and are considered to be the most important approach to biodiversity conservation. Besides climate change, increasing human population is the biggest threat to biodiversity and habitats in PAs. In this paper, the temporal and spatial variations of land cover changes (LCC), vegetation fraction (VFC), and net primary productivity (NPP) were studied to present the ecosystem dynamics of habitats in 6 different types of national nature reserves (NNRs) in 8 climate zones in China. Furthermore, we used Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light datasets and the human disturbance (HD) index estimated from LCC to quantify the living and developing human pressures within the NNRs in the period 2000–2013. The results showed that (1) the living human activities of NNRs increased apparently in the humid warm-temperate zone, Qinghai-Tibet Plateau, mid-temperate semi-arid zone, and mid-temperate humid zone, with the highest increase of nighttime light observed in inland wetlands; (2) the developing human activities in NNRs indicated by the HD index were higher in the humid warm-temperate zone and mid-temperate semi-arid zone as a result of increasing areas of agricultural and built activities, and lower in the sub-tropics due to improved conservation of forest ecosystems; (3) the relationship between HD and VFC suggests that ecosystems in most NNRs of south-subtropics, mid-temperate arid zone and Qinghai-Tibet Plateau were predominantly impacted by climate change. However, HDs were the prevalent factor of ecosystem dynamics in most NNRs of north-subtropics, mid-temperate semi-arid and humid zones.

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MONDAL, S. S. "Moisture availability and its application in evaluating agriculture potential in semi-arid region." MAUSAM 42, no. 1 (February 28, 2022): 65–70. http://dx.doi.org/10.54302/mausam.v42i1.2845.

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The States of Punjab and. Haryana generally belong to part of arid and semi-arid regions of India. An Index known as Moisture Availability Index (MAI) has been used to demarcate it into different agroclimatic zones. The four zones Identified were named Very Low Potential (VLP) Low Potential (LP) Moderate Potential (MP) and High Potential (HP) zones. The zone V.LP had the lowest crop potential area where crops are possible in only 20.30% of the years A short duration rainfed crop of 10-12 weeks duration may be grown from zone LP while in area MP the crop growing potential is slightly more. From agricultural point of view area HP appears best suited with minimum risk. Crop prospects at one station In each zone at various risk levels have also been discussed.

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Brown, Dominic, John Taylor, and Martin Bell. "The demography of desert Australia." Rangeland Journal 30, no. 1 (2008): 29. http://dx.doi.org/10.1071/rj07043.

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In recent years, with the formation of organisations such as the Desert Knowledge Cooperative Research Centre, social science interest in the Australian desert has re-surfaced with a research emphasis that is focused on creating sustainable futures for the region. One consequence of this is a demand for detailed demographic information to allow an assessment of different quanta of need in social and economic policy, and for assessment of the impact of these in environmental policy. However, demographic analysis on human populations in the desert to date has attracted very little research attention. In this paper we begin to address this lack of analysis by focusing on the populations, both aboriginal and non-aboriginal, of the arid and semi-arid zones of Australia. We extend earlier analysis by including for the first time demographic information on the semi-arid as well as the arid zone to establish the spatial pattern of population growth within the whole desert area drawing attention to the resulting settlement structure as an outcome of prevailing social, cultural and economic conditions. By examining population structure and demographic components of population change we also present for the first time population projections for the semi-arid zone and, therefore, in combination with the arid zone, for the entire Australian desert. All of this provides a basis for considering social and economic policy implications and the nature of underlying processes that drive change in this region.

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Kehal, Lamia, Mohamed Zouidi, Dounia Keddari, Salah Hadjout, and Amine Habib Borsali. "Comparative analysis of forest soil properties from sub-humid and semi-arid areas of Djebel El Ouahch biological reserve in Algeria." South Asian Journal of Experimental Biology 12, no. 3 (May 28, 2022): 349–56. http://dx.doi.org/10.38150/sajeb.12(3).p349-356.

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The forest plays a vital role in the biological, ecological and economic balance in our country. It is the result of millenary interactions between the climate, the diversity of geological and edaphic contexts. The objective of this study was to determine and evaluate the physicochemical parameters of forest soils in two zones of the Djebel El Ouahch (Constantine) national park, which were exposed to two bioclimatic stages (sub-humid and semi-arid). The samples were taken at a depth between 0 and 20 cm in each zone on sampling stations of 400 m2. Our results showed that the bioclimatic stage affected the physico-chemical properties of the soils by increasing the percentage of humidity, the rate of carbon, nitrogen and organic matter in the sub-humid zone, on the other hand in the semi-arid zone are vulnerable and fragile due to their texture, a low water retention capacity, the rate of degradation of organic matter and a high rate of total limestone. The intense drying and the vulnerability of the soils in the semi-arid zone could reduce the long-term physico-chemical fertility with the consequence of a regression of the vegetation and the alteration of the biodiversity.

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Allam, Ayoub, Amine Habib Borsali, Abdelkrim Kefifa, Mohamed Zouidi, and Raphael Gros. "Effect of Fires on Certain Properties of Forest Soils in Western Algeria." Acta Technologica Agriculturae 23, no. 3 (September 1, 2020): 111–17. http://dx.doi.org/10.2478/ata-2020-0018.

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AbstractNatural disturbances, such as forest fires, cause significant changes in the structure and functioning of semi-arid ecosystems. After such disturbances, the impact on the soil ecosystem in its entirety is misunderstood. In this study, two years after the last fire, changes in the physicochemical and biological properties of Aleppo pine forest soils in the semi-arid zone were observed. Among all physical properties analysed, only the soil moisture remained significantly lower in the burnt zone in contrast to control zone. Considering the chemical properties, the only negatively affected parameter is the rate of organic matter. In terms of biological properties, results showed that the fire caused a significant decrease in soil microorganisms by decreasing basal respiration and microbial biomass. Conversely, the metabolic quotient recorded higher values in the fire zone than in the control zone. These results indicate that microbial communities in semi-arid soils, already stressed by climatic hazards, are very sensitive to the passage of even low-intensity fires.

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Bello, Abdulrahman. "Rabbit Production in Semi Arid Zone of Sokoto State." American Journal of Biomedical Science & Research 7, no. 3 (February 18, 2020): 224–32. http://dx.doi.org/10.34297/ajbsr.2020.07.001147.

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Fenetahun, Yeneayehu, and Tihunie Fentahun. "Socio-economic profile of arid and semi-arid agropastoral region of Borana rangeland Southern, Ethiopia." MOJ Ecology & Environmental Sciences 5, no. 3 (June 3, 2020): 113–22. http://dx.doi.org/10.15406/mojes.2020.05.00183.

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Ethiopia is believed to have the largest livestock population in Africa. This livestock sector has been contributing considerable portion to the economy of the country and Borana zone is the major contributor for this. The main objectives of the study were to make basic information regarding natural features and socio-economic conditions of the zone that serve or stepping ground for planning policy making and research. This data is crucial for designing proper development plan for research activities and decision making. Specifically, the 2019 socio -economic profile was conducted to provide basic information for the 2020 national election purpose and for 2021 population and housing census as preliminary document regarding socio-economic condition of the zone. And also, this socio-economic profile is used to enhance tourism and economic development, identifying under used services (or opportunities for shared services, forecasting problem areas, developing local community profiles and better land use planning. In organizing this document, the serious problems were the absence of reliable data and up to date data and information. The document being the first of its kind gives a general clue about the zone and accordingly could be used as a bench mark for further study about the zone.

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Yan, Zhongwei, and Nicole Petit-Maire. "The last 140 ka in the Afro-Asian arid/semi-arid transitional zone." Palaeogeography, Palaeoclimatology, Palaeoecology 110, no. 3-4 (August 1994): 217–33. http://dx.doi.org/10.1016/0031-0182(94)90085-x.

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Nemati, Ahmad, Seyed Hossein Ghoreishi Najafabadi, Gholamreza Joodaki, and S. Saeid Mousavi Nadoushani. "Monitoring and Analysis of Drought Using Gravity Recovery and Climate Experiment (GRACE)." Hydrology 6, no. 3 (August 25, 2019): 75. http://dx.doi.org/10.3390/hydrology6030075.

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Drought monitoring needs comprehensive and integrated meteorological and hydrologic data. However, such data are generally not available in extensive catchments. The present study aimed to analyze drought in the central plateau catchment of Iran using the terrestrial water storage deficit index (TSDI). In this arid catchment, the meteorological and hydrologic observed data are scarce. First, the time series of terrestrial water storage changes (TWSC) obtained from the gravity recovery and climate experiment (GRACE) was calculated and validated by the water budget output. Then, the studied area was divided into semi-arid, arid, and hyper-arid zones and the common drought indices of SPI and RDIe within a timescale of 3, 6, and 12 months were calculated to compare the results obtained from the TSDI by using the meteorological data of 105 synoptic stations. Based on the results, the study area experienced a drought with extreme severity and expansion during 2007–2008. The drought spatial distribution map obtained from three indices indicated good conformity. Based on the maps, the severity, duration, and frequency of drought in the semi-arid zone were greater than that in other zones, while no significant drought occurred in the hyper-arid zone. Furthermore, the temporal distribution of drought in all three zones indicated that the TSDI could detect all short- and long-term droughts. The study results showed that the TSDI is a reliable, integrated, and comprehensive index. Using this index in arid areas with little field data led to some valuable results for planning and water resource management.

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SINGH, HARKANWALJOT, P. K. KINGRA, R. K. PAL, and SOMPAL SINGH. "Improving heat use efficiency of wheat (Triticumaestivum L.) under abiotic stresses in semi-arid and arid agroclimatic conditions of Punjab." MAUSAM 72, no. 3 (October 22, 2021): 673–80. http://dx.doi.org/10.54302/mausam.v72i3.1319.

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A field experiment was conducted in two agroclimatic zones of the Punjab (viz., Ludhiana representing semi-arid and Bathinda representing arid zone) to study the phenologicalbehaviour and heat use efficiency of wheat under abiotic stresses. The wheat variety HD-2967 was evaluated under five thermal environments (D1- 20th October, D2-5th November, D3- 20th November, D4- 5th December and D5- 20th December) to expose the crop to different thermal environments and two nitrogen levels (N1- Recommended dose of N and N2- 25 per cent less than recommended N) in main plots and two irrigation levels (I1 - Optimal (recommended) irrigation (Irrigation at CRI, Jointing, Flowering and Soft dough stage) and I2 - Sub-optimal irrigation (one irrigation less than recommended) (Irrigation at CRI, Flag leaf emergence and Soft dough stage) in sub-plots during two consecutive rabi seasons of 2017-18 and 2018-19. It was found that the wheat crop sown in semi-arid zone i.e., Ludhiana took more number of days to reach physiological maturity. The number of days required to attain different phenological stages decreased with delayed sowing at both the locations. The crop utilized heat more efficiently in the arid zone i.e., Bathinda. At Ludhiana, highest HUE was observed in the crop sown on 20th November (3.08 kg/ha/°C/day) and 5th November (3.18 kg/ha/°C/day) during 2017-18 and 2018-19, respectively; whereas at Bathinda, HUE was highest in the crop sown on 5th November (3.31 and 3.32 kg/ha/°C/day) during both the years. Recommended dose of nitrogen and optimal irrigation also produced significantly higher HUE at both the locations during both the years. The study concluded that timely sowing of the crop along with recommended nitrogen and optimal irrigation can significantly improve efficiency of heat utilisation both in semi-arid and arid agroclimatic conditions.

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Turner, Dorothy, Megan Lewis, and Bertram Ostendorf. "Spatial indicators of fire risk in the arid and semi-arid zone of Australia." Ecological Indicators 11, no. 1 (January 2011): 149–67. http://dx.doi.org/10.1016/j.ecolind.2009.09.001.

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Barrow, Lauren, Catherine L. Parr, and James L. Kohen. "Biogeography and diversity of ants in Purnululu (Bungle Bungle) National Park and Conservation Reserve, Western Australia." Australian Journal of Zoology 54, no. 2 (2006): 123. http://dx.doi.org/10.1071/zo06009.

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We describe the diversity, composition, functional group organisation and biogeography of ants in Purnululu National Park (128°19′E, 17°19′S) in Western Australia’s Kimberley region, located at a semi-arid/tropical zone boundary. Pitfall trapping collected a representative sample of ants from three main habitats within the park: spinifex, sandplain and gorges. In total, 154 species from 25 genera were collected. The richest genera were Melophorus, Iridomyrmex and Monomorium. Iridomyrmex was the most abundant genus, accounting for 80% of all individuals recorded in traps. Functional group composition was dominated by Dominant Dolichoderinae (41% of individuals collected) and Hot Climate Specialists (26%). Biogeographical composition was typical of semi-arid zone assemblages located on the overlap between Eyrean and Torresian zones: 50% of the species recorded represented Eyrean taxa, followed by 33% with Torresian affinities, and 10% Widespread. Differences in ant species richness, abundance and assemblage composition between the three habitat types were attributed to a combination of variation in vegetation structure and microhabitat composition. This paper provides baseline data on local ant communities in the semi-arid Kimberley, enabling a greater understanding of the conservation value of reserves within the Kimberley, one of Australia’s least studied bioregions.

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Gupta, Rajiv, and Gaurav Kumar. "Scenario planning for water resource management in semi arid zone." Physics and Chemistry of the Earth, Parts A/B/C 105 (June 2018): 290–99. http://dx.doi.org/10.1016/j.pce.2017.12.004.

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Na, Risu, Li Na, Haibo Du, Hong S. He, Yin Shan, Shengwei Zong, Lirong Huang, Yue Yang, and Zhengfang Wu. "Vegetation Greenness Variations and Response to Climate Change in the Arid and Semi-Arid Transition Zone of the Mongo-Lian Plateau during 1982–2015." Remote Sensing 13, no. 20 (October 12, 2021): 4066. http://dx.doi.org/10.3390/rs13204066.

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Vegetation greenness dynamics in arid and semi-arid regions are sensitive to climate change, which is an important phenomenon in global climate change research. However, the driving mechanism, particularly for the longitudinal and latitudinal changes in vegetation greenness related to climate change, has been less studied and remains poorly understood in arid and semi-arid areas. In this study, we investigated changes in vegetation greenness and the vegetation greenness line (the mean growing season normalized difference vegetation index (NDVI) = 0.1 contour line) and its response to climate change based on AVHRR-GIMMS NDVI3g and the fifth and latest global climate reanalysis dataset from 1982 to 2015 in the arid and semi-arid transition zone of the Mongolian Plateau (ASTZMP). The results showed that the mean growing season NDVI increased from the central west to east, northeast, and southeast in ASTZMP. The vegetation greenness line migrated to the desert during 1982–1994, to the grassland during 1994–2005, and then to the desert during 2005–2015. Vegetation greenness was positively correlated with precipitation and negatively correlated with temperature. The latitudinal variation of the vegetation greenness line was mainly affected by the combination of precipitation and temperature, while the longitudinal variation was mainly affected by precipitation. In summary, precipitation was a key climatic factor driving rapid changes in vegetation greenness during the growing season of the transition zone. These results can provide meaningful information for research on vegetation coverage changes in arid and semi-arid regions.

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S.K. JALOTA and B.B. VASHISHT. "Adapting cropping systems to future climate change scenario in three agro-climatic zones of Punjab, India." Journal of Agrometeorology 18, no. 1 (June 1, 2016): 48–56. http://dx.doi.org/10.54386/jam.v18i1.899.

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The present study focuses on (1) projections of future climate data (for the years of 2020, 2050 and 2080) from three general circulation models (HadCM3, CCCMA-CGCM2 and CSIRO-MK2) for two scenarios (A2 and B2) for three agro-climatic zones of the Indian Punjab (ii) assessment of climate change impact on productivity of maize-wheat cropping system in moist to dry sub-humid, rice-wheat in hot dry semiarid and cotton-wheat in hot arid zones and (iii) evaluation of shifting planting dates as an adaptation measure to sustain crop yields. The results indicate that in future the magnitude of climate change and variability would vary with agro-climatic zone, model and scenario. Maximum temperature, minimum temperature and rainfall would be higher in moist to dry sub-humid zone than hot arid. Simulations with cropping system model anticipated reduction in yields of all the three cropping systems for future years; however, cotton crop was more vulnerable than maize and rice. Delaying trans/planting of maize by 7 days in sub humid zone, rice by 7-15 days in semi arid and cotton by 21 days in arid zone in future emerged as doable adaptation measure to minimize yield reduction in future.

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BIDINGER, F. R., O. P. YADAV, and E. WELTZIEN RATTUNDE. "GENETIC IMPROVEMENT OF PEARL MILLET FOR THE ARID ZONE OF NORTHWESTERN INDIA: LESSONS FROM TWO DECADES OF COLLABORATIVE ICRISAT-ICAR RESEARCH." Experimental Agriculture 45, no. 1 (January 2009): 107–15. http://dx.doi.org/10.1017/s0014479708007059.

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SUMMARYThe arid zone of northwestern India is a unique adaptation zone for crop plants because of its pervasive severe moisture stress and high temperatures. Pearl millet (Pennisetum glaucum) is a major cereal in this zone as it represents approximately 25% of the total acreage of the crop in the country. Pearl millet hybrid cultivars, which have gained widespread acceptance from farmers elsewhere in the country, have not been adopted in the arid zone. Farmers continue to sow their traditional landraces because the yield advantage of current hybrids is not expressed in this zone, and the risk of failure in poor years with the hybrids is unacceptably high. The International Crops Research Institute for the Semi-Arid Tropics and the Indian Council of Agricultural Research have been collaborating to understand the unique nature of pearl millet in the arid zone since the late 1980s. This collaboration has produced a better understanding of how arid zone farmers manage their germplasm, of the unique features of this invaluable resource and of a range of ways of using this germplasm to produce well-adapted new varieties and hybrids that will meet the requirements of the farmers of the arid zone. It has been shown that new cultivars for the arid zone need to be based on parental materials, including traditional landraces that are specifically adapted to the arid zone. This paper summarizes the main lessons of nearly 20 years of this collaborative research.

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Schaller, Mirjam, and Todd A. Ehlers. "Comparison of soil production, chemical weathering, and physical erosion rates along a climate and ecological gradient (Chile) to global observations." Earth Surface Dynamics 10, no. 1 (February 15, 2022): 131–50. http://dx.doi.org/10.5194/esurf-10-131-2022.

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Abstract. Weathering of bedrock to produce regolith is essential for sustaining life on Earth and global biogeochemical cycles. The rate of this process is influenced not only by tectonics, but also by climate and biota. We present new data on soil production, chemical weathering, and physical erosion rates from the large climate and ecological gradient of the Chilean Coastal Cordillera (26 to 38∘ S). Four Chilean study areas are investigated and span (from north to south) arid (Pan de Azúcar), semi-arid (Santa Gracia), Mediterranean (La Campana), and temperate humid (Nahuelbuta) climate zones. Observed soil production rates in granitoid soil-mantled hillslopes range from ∼7 to 290 t km−2 yr−1 and are lowest in the sparsely vegetated and arid north and highest in the Mediterranean setting. Calculated chemical weathering rates range from zero in the arid north to a high of 211 t km−2 yr−1 in the Mediterranean zone. Chemical weathering rates are moderate in the semi-arid and temperate humid zones (∼20 to 50 t km−2 yr−1). Similarly, physical erosion rates are lowest in the arid zone (∼11 t km−2 yr−1) and highest in the Mediterranean climate zone (∼91 t km−2 yr−1). The contribution of chemical weathering to total denudation rates is lower in the arid north than further south. However, due to heterogeneities in lithologies and Zr concentrations, reported chemical weathering rates and chemical depletion fractions are affected by large uncertainties. Comparison of Chilean results to published global data collected from hillslope settings underlain by granitoid lithologies documents similar patterns in soil production, chemical weathering, and total denudation rates for varying mean annual precipitation and vegetation cover amounts. We discuss the Chilean and global data in the light of contending model frameworks in the literature and find that observed variations in soil production rates bear the closest resemblance to models explicitly accounting for variations in soil thickness and biomass.

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Noble, JC, RSB Greene, and WJ Muller. "Herbage Production Following Rainfall Redistribution in a Semi-Arid Mulga (Acacia Aneura) Woodland in Western New South Wales." Rangeland Journal 20, no. 2 (1998): 206. http://dx.doi.org/10.1071/rj9980206.

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The effects of stocking rate (nominally ranging from 0.3 up to 0.8 dry sheep equivalents per ha) on rainfall redistribution, soil-water storage and herbage production were studied in three contiguous geomorphic zones (run-off, interception and run-on zones) in a semi-arid mulga (Acacia aneura) woodland in western New South Wales. The amount of rainfall redistribution increased directly with rainfall but there was no significant effect of stocking rate on the amount of soil-water stored in various zones. while soil-water storage differed little between zones following a minor rainfall event (11.9 mm), it was significantly higher (P < 0.001) in the run-on zone following a major rainfall event (42.7 mm). The interception zone was by far the most productive herbage zone contributing a significantly (P < 0.01) disproportionate amount of forage (c. 90% of total paddock production at low stocking rates) despite this zone only occupying a relatively small proportion (c. 12%) of landscape catenae. Herbage in the interception zone principally comprised palatable C3 perennial grasses such as Thyridolepis mitchelliana (mulga grass) and Monachather paradoxa (bandicoot grass). Experimental manipulation confirmed the fundamental importance of rainfall redistribution as a landscape process mediating herbage production in these semi-arid plant communities. Dry matter production by Eragrostis eriopoda (woollybutt) was significantly enhanced (P < 0.05) in the run-off zone when incident rainfall was retained in situ by metal barriers. Conversely, production by Thyridolepis mitchelliana in the lower interception zone was significantly depressed (P < 0.01) where similar barriers prevented access by overland flow. The results are discussed in the context of developing conservative management strategies designed to maintain effective landscape processes in these extensive ecosystems.

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Mokgehle, Salmina, Nadia Araya, Motiki Mofokeng, Manaka Makgato, Stephen Amoo, Khomotso Maboka, Christian du Plooy, and Hintsa Araya. "Regrowth Response and Nutritional Composition of Moringa oleifera to Cutting Back in Three Agro-Ecological Zones in South Africa." Horticulturae 8, no. 10 (October 18, 2022): 963. http://dx.doi.org/10.3390/horticulturae8100963.

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Moringa (Moringa oleifera Lam.) is a fast-growing tree that can reach a height of 3 m when left to grow naturally. Cutting-back management can enhance lateral branching, water use efficiency, regrowth, and leaf biomass production. Although M. oleifera can thrive in diverse ecological environments, including areas with high temperatures and drought where most crops cannot survive, the prevailing agro-ecological conditions can influence the tree’s response to cut-back and nutritional composition. An observation trial on the re-sprouting of M. oleifera after cutting back was conducted in three agro-ecological zones, including arid, semi-arid, and dry sub-humid regions. The soil analysis from the three agro-ecological zones showed variations, with the soil collected from the arid area recording the highest clay content (24.4%), nitrogen (8.14%), and phosphorus (168.2 mg/kg). The nutritional composition of the M. oleifera leaves in response to the cutting back was assessed. The trees planted in the arid region responded well to the cutting back by producing considerable new vegetative growth in the spring (13.4 sprouts averaging 21.50 cm in length) compared to semi-arid and dry sub-humid regions. The region’s climatic conditions favoured M. oleifera re-sprouting, and the stems did not die after cutting back. During the winter, the stems die back, sprout from the root collar area during more favourable weather conditions, and take longer to reach the harvestable stage. The leaves of M. oleifera harvested from the arid and dry sub-humid regions exhibited increased total fat, magnesium, sodium, phosphorus, potassium, and zinc content when compared to the semi-arid agro-ecological zone. In contrast, the calcium content of the leaves was higher in the semi-arid region than in the other agro-ecological zones. The influence of cutting back M. oleifera trees on biomass production and quality in varying agro-ecological zones requires further investigation to ensure that smallholder farmers use appropriate crop management practices in those regions for long-term, economically viable tree production.

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Li, Mingqian, Xiujuan Liang, Changlai Xiao, Yuqing Cao, and Shuya Hu. "Hadrochemical Evolution of Groundwater in a Typical Semi-Arid Groundwater Storage Basin Using a Zoning Model." Water 11, no. 7 (June 28, 2019): 1334. http://dx.doi.org/10.3390/w11071334.

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Groundwater guarantees water resources and ecological environment security in semi-arid areas. Studying the chemical evolution of groundwater in semi-arid areas is of great significance to regional ecological environment protection and water resources management. The water storage basin is not only a space for groundwater storage and movement but also a place for water–rock–gas interaction and elemental migration, dispersion, and enrichment. Due to its unique climate and geological environment, the semi-arid water storage basins have different hydrochemical environments, forming a zonal hydrogeochemical character. In this study, a typical semi-arid water storage basin (west of Jilin Province) is taken as an example, through the cross section of the recharge–runoff–excretion zone. A three-level hydrogeochemical zoning model is constructed to reveal the hydrogeochemical evolution of the area. The model is divided into three layers from bottom to top. The first layer shows the geological and hydrogeological conditions, including the topography, lithology, geological time, and hydrodynamic characteristics of the study area. The second layer represents the hydrogeochemical processes, divided into the recharge zone, runoff zone, and discharge zone in the horizontal direction according to the hydrodynamic environment and hydrochemistry type. The hydrogeochemical action gradually changes from lixiviation to cation exchange, evaporation, and concentration, as the landform plays a key role in hydrochemistry formation in the discharge area. The third layer gives the characteristics of the groundwater chemical components, including chemistry type, total dissolved solids, main anion and cation, and characteristic element F. Qualitative and quantitative characterizations of hydrochemistry evolution by reverse simulation and hydrodynamic, hydrochemical and thermodynamic indicators are given.

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Li, Ming, Fuqiang Cao, Guiwen Wang, Xurong Chai, and Lianzhi Zhang. "Evolutional Characteristics of Regional Meteorological Drought and Their Linkages with Southern Oscillation Index across the Loess Plateau of China during 1962–2017." Sustainability 12, no. 18 (September 4, 2020): 7237. http://dx.doi.org/10.3390/su12187237.

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The Loess Plateau of China (CLP) is located in the transition zone from a semi-humid climate zone to semi-arid and arid climate zones. It is influenced by the westerly circulation, plateau monsoon, and East Asian monsoon circulation, and the drought disasters across the CLP have obvious regional characteristics. In this study, climate regionalization was performed by a spatial hierarchical cluster approach based on the gridded datasets of monthly precipitation across the CLP from 1961 to 2017. Then, the standardized precipitation index (SPI) was used to explore the temporal evolution of regional meteorological droughts. Finally, wavelet methods were used to investigate the drought cycles in each homogeneous subregion and the linkages between SPI and the Southern Oscillation Index (SOI). The results show that: (1) Spatially, the CLP can be divided into four homogeneous regions, namely, Ordos Plateau semi-arid area (Region I), Northern Shanxi hilly semi-humid area (Region II), Longzhong plateau cold-arid area (Region III), and Fenwei Plain and Shaanxi-Shanxi hilly semi-humid area (Region IV). (2) There are apparent differences in the temporal evolution of meteorological droughts in different subregions, but two wet periods from the 1960s to 1980s and 2010s, and a drought period in the 1990s, can be found in each subregion. (3) There is a significant drought cycle of 3–8 years in the four subregions, and the first main cycles of drought variation are not completely consistent. (4) The linkages between SPI and SOI are time- and space-dependent and the phase differences are dominated by in-phase. The strongest correlations between the two time series occur in the 1980s in the four subregions. The results of this research have important implications for the establishment of drought monitoring programs in homogeneous climate regions, and informed decision making in water resource management.

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Gbahabo, Terfa Percy. "Peasant households livelihoods negotiation in the semi-arid zone of Nigeria." International Journal of Sociology and Anthropology 7, no. 7 (July 30, 2015): 158–67. http://dx.doi.org/10.5897/ijsa2014.0570.

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Field, Judith H., John R. Dodson, and Ian P. Prosser. "A Late Pleistocene vegetation history from the Australian semi-arid zone." Quaternary Science Reviews 21, no. 8-9 (April 2002): 1023–37. http://dx.doi.org/10.1016/s0277-3791(01)00057-9.

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Warnock, A. D., M. E. Westbrooke, S. K. Florentine, and C. P. Hurst. "Does Geijera parviflora Lindl. (Rutaceae) facilitate understorey species in semi-arid Australia?" Rangeland Journal 29, no. 2 (2007): 207. http://dx.doi.org/10.1071/rj07032.

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Species composition under tree canopies often differs from that of surrounding micro-environments. In arid and semi-arid zones, trees can be beneficial to understorey vegetation. This study examined zones of vegetation composition and soil physiochemical parameters associated with Geijera parviflora Lindl. The importance of shade, rainfall redistribution, seed bank and soil moisture were examined. Species abundance, soil moisture, seed bank composition, rainfall redistribution and soil nutrient concentration were measured under five randomly selected mature G. parviflora trees in south-western New South Wales, Australia. To complement the findings from this study, artificial shade plots were constructed in a canopy-free area and species abundance measured seven months after shade construction. The study demonstrated that G. parviflora was associated with zonation of understorey vegetation. Two zones of understorey vegetation were found in relation to G. parviflora: (i) under the tree canopy with high species diversity, and (ii) beyond the canopy, this community being dominated by Dissocarpus paradoxus throughout the year with Crassula colorata appearing after rainfall. The zone beyond the canopy also had lower soil nutrient concentrations. Soil moisture, nutrient concentration and the seed bank density were significantly higher under the canopy. However, the canopy reduced precipitation reaching the soil surface. The effects of the canopy on understorey species composition and soil moisture were enhanced after winter rainfall. Artificial shade increased species abundance and richness under a 90%-shading treatment. The results indicated that G. parviflora generated spatial heterogeneity over the broader plant community increasing species richness, abundance and diversity under the canopy. This emphasises the importance of arid zone trees in conserving understorey plant diversity. Shading, soil nutrient concentration and increased seed bank density and soil moisture appeared to be key influences on the plant communities under the canopy.

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Bona, Elisa, Nadia Massa, Omrane Toumatia, Giorgia Novello, Patrizia Cesaro, Valeria Todeschini, Lara Boatti, et al. "Climatic Zone and Soil Properties Determine the Biodiversity of the Soil Bacterial Communities Associated to Native Plants from Desert Areas of North-Central Algeria." Microorganisms 9, no. 7 (June 23, 2021): 1359. http://dx.doi.org/10.3390/microorganisms9071359.

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Algeria is the largest country in Africa characterized by semi-arid and arid sites, located in the North, and hypersaline zones in the center and South of the country. Several autochthonous plants are well known as medicinal plants, having in common tolerance to aridity, drought and salinity. In their natural environment, they live with a great amount of microbial species that altogether are indicated as plant microbiota, while the plants are now viewed as a “holobiont”. In this work, the microbiota of the soil associated to the roots of fourteen economically relevant autochthonous plants from Algeria have been characterized by an innovative metagenomic approach with a dual purpose: (i) to deepen the knowledge of the arid and semi-arid environment and (ii) to characterize the composition of bacterial communities associated with indigenous plants with a strong economic/commercial interest, in order to make possible the improvement of their cultivation. The results presented in this work highlighted specific signatures which are mainly determined by climatic zone and soil properties more than by the plant species.

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Schagen, Micaela, Jason Bosch, Jenny Johnson, Robbert Duker, Pedro Lebre, Alastair J. Potts, and Don A. Cowan. "The soil microbiomics of intact, degraded and partially-restored semi-arid succulent thicket (Albany Subtropical Thicket)." PeerJ 9 (October 6, 2021): e12176. http://dx.doi.org/10.7717/peerj.12176.

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This study examines the soil bacterial diversity in the Portulacaria afra-dominated succulent thicket vegetation of the Albany Subtropical Thicket biome; this biome is endemic to South Africa. The aim of the study was to compare the soil microbiomes between intact and degraded zones in the succulent thicket and identify environmental factors which could explain the community compositions. Bacterial diversity, using 16S amplicon sequencing, and soil physicochemistry were compared across three zones: intact (undisturbed and vegetated), degraded (near complete removal of vegetation due to browsing) and restored (a previously degraded area which was replanted approximately 11 years before sampling). Amplicon Sequence Variant (ASV) richness was similar across the three zones, however, the bacterial community composition and soil physicochemistry differed across the intact and degraded zones. We identified, via correlation, the potential drivers of microbial community composition as soil density, pH and the ratio of Ca to Mg. The restored zone was intermediate between the intact and degraded zones. The differences in the microbial communities appeared to be driven by the presence of plants, with plant-associated taxa more common in the intact zone. The dominant taxa in the degraded zone were cosmopolitan organisms, that have been reported globally in a wide variety of habitats. This study provides baseline information on the changes of the soil bacterial community of a spatially restricted and threatened biome. It also provides a starting point for further studies on community composition and function concerning the restoration of degraded succulent thicket ecosystems.

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35

Ren, Xueyuan, Qiang Zhang, Ping Yue, Jinhu Yang, and Sheng Wang. "Environmental and Biophysical Effects of the Bowen Ratio over Typical Farmland Ecosystems in the Loess Plateau." Remote Sensing 14, no. 8 (April 14, 2022): 1897. http://dx.doi.org/10.3390/rs14081897.

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The Bowen ratio (β) comprehensively reflects physical characteristics of the land-surface climate. In this study, eddy covariance systems installed at Dingxi and Qingyang were used to conduct energy distribution measurements and observations characteristic of semi-arid and semi-humid farmland ecosystems on the China Loess Plateau. We studied mechanisms by which eco-environmental factors influence β. Additionally, we investigated responses of physiological and ecological factors to water and heat exchange under seasonally dry and wet conditions within each farmland ecosystem. Our results showed that sensible heat flux in the semi-arid farmland was the main consumer of available energy. In the semi-humid area, latent heat flux in summer had the dominant role in energy distribution (mean β 0.71). The β in the semi-arid region was 1.5 times higher than that in the semi-humid region during the growing season. β increased with an increase in the vapor pressure deficit (VPD) and ground–air temperature difference (Ts − Ta), and decreased significantly with an increase in effective precipitation and soil moisture. The change in β with environmental factors was more clear-cut in semi-arid areas than in semi-humid areas. The Priestley–Taylor coefficient (α) and β satisfied a power function law in the growing season. There was a strong correlation between them, with the coefficients of determination for semi-humid and semi-arid areas being 0.62 and 0.72, respectively. β decreased with an increase in the normalized difference vegetative index (NDVI), with this phenomenon being more obvious in the semi-humid zone (R2 = 0.40). β responded more rapidly to NDVI in the semi-arid area than in the semi-humid area. There was a negative exponential relationship between canopy stomatal conductance (Gs) and β, which displayed a stronger declining trend with the increase in Gs in the semi-arid area than in the semi-humid area. This study provides an important reference for the determination of land-surface characteristics of semi-arid and semi-humid farmland ecosystems on the Loess Plateau and for improving parameterization of land-surface processes.

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Bao, Yige, Xinying Zhou, Hanbin Liu, Songmei Hu, Keliang Zhao, Pia Atahan, John Dodson, and Xiaoqiang Li. "Evolution of prehistoric dryland agriculture in the arid and semi-arid transition zone in northern China." PLOS ONE 13, no. 8 (August 3, 2018): e0198750. http://dx.doi.org/10.1371/journal.pone.0198750.

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Lv, Qing Feng, Peng Fei Liu, and Yan Xu Zhao. "Finite Element Analysis of Rainfall Infiltration in a Compacted Loess Embankment." Advanced Materials Research 936 (June 2014): 1511–17. http://dx.doi.org/10.4028/www.scientific.net/amr.936.1511.

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Because of evapo-transpiration, compacted loess road embankments were considered to be in a partially saturated state in both arid and semi-arid regions. Based on previous studies and the theory of unsaturated soil mechanics, a numerical analysis of rainfall infiltration in a compacted loess road embankment was conducted. The transient seepage characteristics and moisture migration patterns of the moisture in the embankment were analysed. The results showed that after precipitation, the moisture profile of the compacted loess could be separated into three zones .The data also showed that: under the effect of gravity, the water continued to migrate into the embankment after the rainfall had ended. In time, the saturated zone became partially saturated as the moisture content decreased, whereas the moisture content in the conducting and humid zones increased and the wetting front moved downward. The data also showed that the depth of the conducting and humid zones increased in time, but that the moisture content in the conducting zone increased along a linear gradient with depth, while the moisture content in the humid zone decreased in a similar manner.

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Castellini, Mirko, Simone Di Prima, Ryan Stewart, Marcella Biddoccu, Mehdi Rahmati, and Vincenzo Alagna. "Advances in Ecohydrology for Water Resources Optimization in Arid and Semi-Arid Areas." Water 14, no. 12 (June 7, 2022): 1830. http://dx.doi.org/10.3390/w14121830.

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Conserving water resources is a current challenge that will become increasingly urgent in future due to climate change. The arid and semi-arid areas of the globe are expected to be particularly affected by changes in water availability. Consequently, advances in ecohydrology sciences, i.e., the interplay between ecological and hydrological processes, are necessary to enhance the understanding of the critical zone, optimize water resources’ usage in arid and semi-arid areas, and mitigate climate change. This Special Issue (SI) collected 10 original contributions on sustainable land management and the optimization of water resources in fragile environments that are at elevated risk due to climate change. In this context, the topics mainly concern transpiration, evapotranspiration, groundwater recharge, deep percolation, and related issues. The collection of manuscripts presented in this SI represents knowledge of ecohydrology. It is expected that ecohydrology will have increasing applications in the future. Therefore, it is realistic to assume that efforts to increase environmental sustainability and socio-economic development, with water as a central theme, will have a greater chance of success.

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Matikeev, T., U. Kamchiev, and K. Abdisalam kyzy. "Landscape Features of the Chatkal Sub-sector in the Tian Shan Mountains." Bulletin of Science and Practice, no. 11 (November 15, 2022): 142–50. http://dx.doi.org/10.33619/2414-2948/84/18.

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Research relevance: open zone is a set of zones of isolated-closed side mountains, and therefore the analysis of the formation of landscape features of the high-altitude zones of the Chatkal sector in Tian Shan mountains is relevant. Research objectives: To reveal the role of altitudinal zones in the formation of landscape features. Materials and methods of research: in the Chatkal sub-sectors, it is important to create a theory of mixing altitudinal zones, that is, the theory of the ‘double zone’ and divide them into types (arid, semi-arid, medium humidity, high humidity and excess moisture). Research results: ‘dual frames’ and ‘the theory of mixing frames’ are raised in scientific research for the first time as a natural phenomenon that causes heated debate in the scientific community. Conclusions: the unity of the frame is created by the concentration of isolated and closed frames of the location of the Tian Shan area at different heights and directions.

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D, Bolormaa, Lkhagvasuren D, Gantuya J, Gankhuyag L, and Altanzul R. "Results of pasture monitoring research." Mongolian Journal of Agricultural Sciences 22, no. 03 (May 9, 2018): 41–45. http://dx.doi.org/10.5564/mjas.v22i03.941.

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Rangeland deterioration and restoration management has been one of the prominent issues. The present study focuses on the composition, cover, and yields accumulation of rangeland plant species from different ecological zones and subzones. Pasture yield in Mongolia varies in ecological zones and subzones (p≥0.001), so 39 sheep, during the summer, comfortably graze in one-hectare area in high mountain zone, - 72 in forest steppe, 21 in steppe and 13 in arid steppe area respectively. Whereas types and cover of plant species in high mountain rangelands are more than other areas, yield accumulation is most in forest steppe. The impact of climate change has dramatically increased recent years, considerably affecting on pasture plant cover and yield. During a dry season or period of drought, amount of yield reduces 40% in high mountain zone; 49% in forest steppe, 52% in semi-arid steppe and 55% in arid steppe. Since rangeland productivity varies due to the nature and climate in the ecological zones and subzones, pasture shall be utilized under appropriate policy that regulates this depending on its capacity, resource and natural and climate feature of area.

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Zhang, W. J., X. J. Wang, M. G. Xu, S. M. Huang, H. Liu, and C. Peng. "Soil organic carbon dynamics under long-term fertilizations in arable land of northern China." Biogeosciences 7, no. 2 (February 2, 2010): 409–25. http://dx.doi.org/10.5194/bg-7-409-2010.

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Abstract. Soil carbon sequestration is a complex process influenced by agricultural practices, climate and soil conditions. This paper reports a study of long-term fertilization impacts on soil organic carbon (SOC) dynamic from six long-term experiments. The experiment sites are located from warm-temperate zone with a double-cropping system of corn (Zea mays L.) – wheat (Triticum Aestivium L.) rotation, to mild-temperate zones with mono-cropping systems of continuous corn, or a three-year rotation of corn-wheat-wheat. Mineral fertilizer applications result in an increasing trend in SOC except in the arid and semi-arid areas with the mono-cropping systems. Additional manure application is important to maintain SOC level in the arid and semi-arid areas. Carbon conversion rate is significant lower in the warm-temperate zone with double cropping system (6.8%–7.7%) than that in the mild-temperate areas with mono-cropping systems (15.8%–31.0%). The conversion rate is significantly correlated with annual precipitation and active accumulative temperature, i.e., higher conversion rate under lower precipitation and/or temperature conditions. Moreover, soil high in clay content has higher conversion rate than soils low in clay content. Soil carbon sequestration rate ranges from 0.07 to 1.461 t ha−1 year−1 in the upland of northern China. There is significantly linear correlation between soil carbon sequestration and carbon input at most sites, indicating that these soils are not carbon-saturated thus have potential to migrate more CO2 from atmosphere.

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Jury, Mark R. "Spreading of the semi-arid climate across South Africa." Journal of Water and Climate Change 12, no. 8 (October 1, 2021): 3734–49. http://dx.doi.org/10.2166/wcc.2021.187.

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Abstract The eastward shift of semi-arid climate across South Africa is studied using satellite assimilated cloud cover, vegetation temperature and potential evaporation 1981–2019, and 21st century coupled model projections. Semi-arid thresholds over the plateau have shifted hundreds of kilometers eastward in the Vaal River catchment for potential evaporation, cloud fraction, and vegetation temperature. Coastal cloudiness has also changed due to sea breezes modified by shelf zone sea temperatures. Processes underlying the spread of semi-arid conditions across South Africa are quantified. Desiccation is related to greater westerly airflow, as the atmospheric boundary layer over the Kalahari preferentially links with the upper-level circulation. Warm dry spells and climate change enhance the meridional temperature gradient and accelerate the sub-tropical jet at both short- and long timescales. According to observations and reanalysis, dry westerlies prevail during the afternoon and induce +0.2 °C/year trends in vegetation temperature over the Highveld during the study period. Coupled model projections show that semi-arid conditions expand eastward from Bloemhof (25.5°E) by 50,000 km2, altering future adaptation strategies.

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Friedel, M. H. "Unwelcome guests: a selective history of weed introductions to arid and semi-arid Australia." Australian Journal of Botany 68, no. 2 (2020): 75. http://dx.doi.org/10.1071/bt20030.

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Following European settlement of Australia, numerous plant species were deliberately introduced for use in crops, pastures, gardens and horticulture, and others arrived by chance. Many subsequently escaped and became weedy. Of the 54 weed species of natural environments of arid and semi-arid Australia that are considered here, 27 were apparently accidentally introduced, 20 were intentionally introduced and 7 were probably introduced both accidentally and intentionally. Livestock including camels and their harness, and contaminated seed and hay were the most common vectors for accidental introduction. Amongst intentional introductions, rather more ornamental species appear to have invaded successfully than pasture species, but the former generally occupy niche habitats. Recent new introductions are few due to pre-border, border and post-border protections, but many current arid zone weeds continue to spread. Understanding the history of weed invasions can help to guide current and future management by clarifying pathways for introduction.

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Mohamedalmontasir A. M. Mohamed and Mahmoud H. Mohamed. "Effect of different periods of irrigation on growth and yield of Cenchrus ciliaris at semi-arid zone of North Darfur State, Sudan." World Journal of Advanced Research and Reviews 9, no. 2 (February 28, 2021): 001–4. http://dx.doi.org/10.30574/wjarr.2021.9.2.0014.

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Buffel grass Cenchrus ciliaris L. (Poaceae) is recognized as one of Australia's most serious environmental weeds. This introduced grass has been associated with loss of native species and alteration of fire regimes. However, it is also highly valued as a pasture species for arid and semi-arid zones and its weed status is highly controversial. This study was conducted at the private farm, Southern part of Alfashir Airport, North Darfur State, Sudan. The objective was to evaluate the effect of different periods of irrigation (DPI) on growth and forage yield of Cenchrus ciliaris during years of 2018 and 2019. The experiment was laid-out in a randomized complete block design (RCBD) with four replicates, the plot size was 8x5 m. Data collected included plant density, plant ground cover, plant height and dry matter yield. DPI showed significant effect on plant density, plant ground cover, Plant height and dry matter yield. The study showed that irrigation every 7 days (Ir1) was suitable for buffel grass at semi-arid zone in Sudan. Quantitative studies are needed to determine its ecological effects.

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Mohamedalmontasir A. M. Mohamed and Mahmoud H. Mohamed. "Effect of seeding rate on plant performance of Alycicarpus ovalifolius under rain-fed in Semi-arid zone, Sudan." World Journal of Advanced Research and Reviews 9, no. 1 (January 30, 2021): 203–6. http://dx.doi.org/10.30574/wjarr.2021.9.1.0013.

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This study was conducted at the private farm, Southern part of Alfashir Airport, under the semi-arid condition of North Darfur State, Sudan. The objective was to test the effect of different seed rates (2, 4, 6, and 8 kg/ha) of Alycicarpus ovalifolius on plant growth attributes and forage yield, during two consecutive seasons (2017 and 2018) aiming to find the most suitable seed rate under rainfed condition in semi-arid zones to be used in pasture improvement. The experiment was laid-out in a randomized complete block design with four replicates, the plot size was 8x5 m. Data collected included Plant density, plant ground cover and dry matter yield. There were significant effects of seeding rates on plant density, cover and yield. Seed rate of 8kg/ha had highest plant density, cover and yield. But the seed rate of 6kg/ha had the optimum performance, this seed rate was recommended for sowing Alycicarpus ovalifolius at semi-arid condition for range improvement. Further research work is needed to assess seeding rates across different ecological zones in North Darfur State.

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Alvar-Beltrán, J., A. Gobin, S. Orlandini, A. Dao, and AD Marta. "Climate resilience of irrigated quinoa in semi-arid West Africa." Climate Research 84 (August 12, 2021): 97–111. http://dx.doi.org/10.3354/cr01660.

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Quinoa (Chenopodium quinoa Willd.) is a herbaceous C3 crop that has demonstrated resilience in regions concurrently affected by climate change and food insecurity, such as sub-Saharan Africa (SSA). The photosynthetic rate and productivity of C3 crops are enhanced under increasing CO2 concentrations. We looked at future climate trends in SSA to estimate their impacts on quinoa yields in Burkina Faso. Climate projections show a temperature increase of 1.67-4.90°C under Representative Concentration Pathways (RCP) 4.5 and 8.5, respectively by the end of the century. We demonstrate that any further climate disturbances can either be beneficial or harmful for quinoa, and modulating climate risks will depend on the decisions made at the farm level (e.g. planting date and crop choice). Crop modelling supports the identification of the most suitable transplanting dates based on future climate conditions (RCP 4.5 and 8.5), agroclimatic zones (Sahel, Soudano-Sahelian and Soudanian) and time-horizons (2020, 2025, 2050 and 2075). We show that quinoa yields can improve—when grown under irrigated conditions and transplanted in November—by about 14-20% under RCP 4.5 and by 24-33% under RCP 8.5 by 2075 across the Sahel and Soudanian agroclimatic zones, respectively. For the Soudano-Sahelian zone, the highest yield improvements (19%) are obtained when transplanting is assumed in December under RCP 8.5 by 2075. Overall, the findings of this work encourage policymakers and agricultural extension officers to further promote climate-resilient and highly nutritious crops. Such possibilities are of much interest in SSA, thought to be highly vulnerable to climate change impacts where millions of people are already experiencing food insecurity.

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Ndiaye, Ousmane, Aly Diallo, Stephen A. Wood, and Aliou Guisse. "Structural Diversity of Woody Species in the Senegalese Semi-Arid Zone—Ferlo." American Journal of Plant Sciences 05, no. 03 (2014): 416–26. http://dx.doi.org/10.4236/ajps.2014.53055.

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Dandekar, A. T., D. K. Singh, A. Sarangi, and A. K. Singh. "Modelling Vadose Zone Processes for Assessing Groundwater Recharge in Semi-Arid Region." Current Science 114, no. 03 (February 10, 2018): 608. http://dx.doi.org/10.18520/cs/v114/i03/608-618.

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Westengen, Ola T., Kristoffer H. Ring, Paul R. Berg, and Anne K. Brysting. "Modern maize varieties going local in the semi-arid zone in Tanzania." BMC Evolutionary Biology 14, no. 1 (2014): 1. http://dx.doi.org/10.1186/1471-2148-14-1.

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Yang, Jianping, Yongjian Ding, Rensheng Chen, and Lianyou Liu. "Fluctuations of the Semi-Arid Zone in China, and Consequences for Society." Climatic Change 72, no. 1-2 (September 2005): 171–88. http://dx.doi.org/10.1007/s10584-005-6858-3.

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Journal articles on the topic 'Semi-arid zone'

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