Pub Date : 2021-08-04DOI: 10.1080/15324982.2021.1957038
M. Javed, M. Ashraf, M. Iqbal, M. Farooq, Z. Zafar, H. Athar
Abstract Efficient selection for salt tolerance using the choice of physiological traits is of great importance. In the present study, seven ecotypes of Panicum antidotale (four from the Cholistan Desert and three from the non-Cholistani area) were evaluated after three weeks of salt stress. Results showed that shoot fresh biomass decreased by 74 and 83% respectively in Cholistani, and non-Cholistani ecotypes under salt-stressed conditions compared to control. Ecotypes from the Cholistan were more salt-tolerant (average dry biomass, 4.02 g) than non-Cholistani ones (average dry biomass, 3.14 g). Averaged across the Cholistani and non-Cholistani ecotypes, Cholistani ecotypes accumulated lower Na+ (72%) and/or higher K+ (179%) concentrations in their leaves than non-Cholistani ecotypes. However, parallels between the degree of salt sensitivity and relative water content, leaf water potential, leaf osmotic potential, and leaf turgor potential could not be generalized. In Cholistani ecotypes under salt stress, the total soluble protein on average was higher (11.51%) compared to non-Cholistani ecotypes (8.5%). Chlorophyll a decreased (0–20%) in all populations due to salt stress and it was positively associated with solar energy absorption and electron transport but could not be used to discriminate the populations. Chlorophyll fluorescence data indicated that salt stress damaged PSII functionality and electron transport further than QA −. The effective quantum yield of PSII, performance index, antenna size, energy flux for electron transport, rate of PSII reaction center closure positively correlated with salt tolerance of P. antidotale.
{"title":"Chlorophyll fluorescence, ion uptake, and osmoregulation are potential indicators for detecting ecotypic variation in salt tolerance of Panicum antidotale Retz*","authors":"M. Javed, M. Ashraf, M. Iqbal, M. Farooq, Z. Zafar, H. Athar","doi":"10.1080/15324982.2021.1957038","DOIUrl":"https://doi.org/10.1080/15324982.2021.1957038","url":null,"abstract":"Abstract Efficient selection for salt tolerance using the choice of physiological traits is of great importance. In the present study, seven ecotypes of Panicum antidotale (four from the Cholistan Desert and three from the non-Cholistani area) were evaluated after three weeks of salt stress. Results showed that shoot fresh biomass decreased by 74 and 83% respectively in Cholistani, and non-Cholistani ecotypes under salt-stressed conditions compared to control. Ecotypes from the Cholistan were more salt-tolerant (average dry biomass, 4.02 g) than non-Cholistani ones (average dry biomass, 3.14 g). Averaged across the Cholistani and non-Cholistani ecotypes, Cholistani ecotypes accumulated lower Na+ (72%) and/or higher K+ (179%) concentrations in their leaves than non-Cholistani ecotypes. However, parallels between the degree of salt sensitivity and relative water content, leaf water potential, leaf osmotic potential, and leaf turgor potential could not be generalized. In Cholistani ecotypes under salt stress, the total soluble protein on average was higher (11.51%) compared to non-Cholistani ecotypes (8.5%). Chlorophyll a decreased (0–20%) in all populations due to salt stress and it was positively associated with solar energy absorption and electron transport but could not be used to discriminate the populations. Chlorophyll fluorescence data indicated that salt stress damaged PSII functionality and electron transport further than QA −. The effective quantum yield of PSII, performance index, antenna size, energy flux for electron transport, rate of PSII reaction center closure positively correlated with salt tolerance of P. antidotale.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"39 1","pages":"84 - 108"},"PeriodicalIF":1.4,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80163263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-22DOI: 10.1080/15324982.2021.1952660
H. Throop, S. Munson, Nicole J. Hornslein, M. McClaran
Abstract Dryland (arid and semi-arid) ecosystems globally provide more than half of livestock production and store roughly one-third of soil organic carbon (SOC). Biogeochemical pools are changing due to shrub encroachment, livestock grazing, and climate change. We assessed how vegetation microsite, grazing, and precipitation interacted to affect SOC and total nitrogen (TN) at a site with long-term grazing manipulations and well-described patterns of shrub encroachment across elevation and mean annual precipitation (MAP) gradients. We analyzed SOC and TN in the context of vegetation cover at ungrazed locations within livestock exclosures, high-intensity grazing locations near water sources, and moderate-intensity grazing locations away from water. SOC was enhanced by MAP (p < 0.0001), but grazing intensity had little effect regardless of MAP (p = 0.12). Shrubs enhanced SOC (300–1279 g C m−2) and TN (27–122 g N m−2), except at high MAP where the contribution or stabilization of shrub inputs relative to grassland inputs was likely diminished. Cover of perennial herbaceous plants and litter were significant predictors of SOC (r 2 = 0.63 and 0.34, respectively) and TN (r 2 = 0.64 and 0.30, respectively). Our results suggest that continued shrub encroachment in drylands can increase SOC storage when grass production remains high, although this response may saturate with higher MAP. In contrast, grazing – at least at the intensities of our sites – has a lesser effect. These effects underscore the need to understand how future climate and grazing may interact to influence dryland biogeochemical cycling.
全球旱地(干旱和半干旱)生态系统提供了一半以上的畜牧业生产，储存了大约三分之一的土壤有机碳(SOC)。生物地球化学库因灌木侵蚀、牲畜放牧和气候变化而发生变化。研究了植被微场、放牧和降水对土壤有机碳(SOC)和总氮(TN)的影响，并对不同海拔和年平均降水(MAP)梯度上的灌木入侵模式进行了描述。我们分析了家畜放养区未放牧区、靠近水源的高强度放牧区和远离水源的中等强度放牧区植被覆盖情况下的有机碳和全氮。放牧强度对土壤有机碳的影响不大(p = 0.12)，而放牧强度对土壤有机碳的影响较小(p < 0.0001)。灌木增加了土壤有机碳(300-1279 g C m−2)和总氮(27-122 g N m−2)，但在高MAP水平，灌木投入相对于草地投入的贡献或稳定性可能降低。多年生草本植物和凋落物盖度是土壤有机碳(r 2分别= 0.63和0.34)和全氮(r 2分别= 0.64和0.30)的显著预测因子。我们的研究结果表明，当草产量保持高时，旱地持续的灌木入侵可以增加有机碳储量，尽管这种响应可能随着MAP的增加而饱和。相比之下，放牧——至少在我们的地点的强度下——的影响较小。这些影响强调了了解未来气候和放牧如何相互作用影响旱地生物地球化学循环的必要性。
{"title":"Shrub influence on soil carbon and nitrogen in a semi-arid grassland is mediated by precipitation and largely insensitive to livestock grazing","authors":"H. Throop, S. Munson, Nicole J. Hornslein, M. McClaran","doi":"10.1080/15324982.2021.1952660","DOIUrl":"https://doi.org/10.1080/15324982.2021.1952660","url":null,"abstract":"Abstract Dryland (arid and semi-arid) ecosystems globally provide more than half of livestock production and store roughly one-third of soil organic carbon (SOC). Biogeochemical pools are changing due to shrub encroachment, livestock grazing, and climate change. We assessed how vegetation microsite, grazing, and precipitation interacted to affect SOC and total nitrogen (TN) at a site with long-term grazing manipulations and well-described patterns of shrub encroachment across elevation and mean annual precipitation (MAP) gradients. We analyzed SOC and TN in the context of vegetation cover at ungrazed locations within livestock exclosures, high-intensity grazing locations near water sources, and moderate-intensity grazing locations away from water. SOC was enhanced by MAP (p < 0.0001), but grazing intensity had little effect regardless of MAP (p = 0.12). Shrubs enhanced SOC (300–1279 g C m−2) and TN (27–122 g N m−2), except at high MAP where the contribution or stabilization of shrub inputs relative to grassland inputs was likely diminished. Cover of perennial herbaceous plants and litter were significant predictors of SOC (r 2 = 0.63 and 0.34, respectively) and TN (r 2 = 0.64 and 0.30, respectively). Our results suggest that continued shrub encroachment in drylands can increase SOC storage when grass production remains high, although this response may saturate with higher MAP. In contrast, grazing – at least at the intensities of our sites – has a lesser effect. These effects underscore the need to understand how future climate and grazing may interact to influence dryland biogeochemical cycling.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"26 1","pages":"27 - 46"},"PeriodicalIF":1.4,"publicationDate":"2021-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90264375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-07DOI: 10.1080/15324982.2021.1946206
S. Cotroneo, E. Jacobo, M. Brassiolo, R. Golluscio
Abstract In semiarid Chaco, wet season grazing exclosures allow a rapid grass recovery in mature and secondary forest patches, but not in the most degraded patches dominated by shrublands. In order to understand the causes of their dissimilar rehabilitation dynamics, we analyzed the effects of the forest-patch type (mature forest = MF, secondary forest = SF, and shrubland = S) and 4-year seasonal exclosures (vs continuous grazing) on biotic and abiotic factors (vegetation structure, incident radiation, grass seed bank, litter and soil traits) that could affect grass recovery. We found that vegetation structure, through determining litter quantity, controlled soil chemical traits. As forest degradation level increased, litter mass (MF = 6260, SF = 5410, S = 1220 kg DM/ha), total soil organic matter (MF = 5.1%, SF = 4.1%, S = 3.5%) and nitrogen (MF = 0.25%, SF = 0.22%, S = 0.18%) decreased, and the incident radiation at soil level rose (MF = 28%, SF = 41%, S = 52%). After 4 years of seasonal grazing rest, we found reduced soil bulk density (from 1.13 to 1.07 and 1.07 to 1 g/cm3) and increased total porosity (from 57 to 60 and 60 to 62%) at 0–10 and 10–30 cm depth, respectively, in all forest patch types. Exclosure also increased soil seed bank density (from 28 to 251 grass seeds/m2) both in the forests (with grass) and in the shrublands (even before grass recovery), which would receive seeds from the adjacent forest patches, which coexist in the same landscape matrix. Our results suggest that the low tree cover, litter, and soil chemical traits related to lower availability of water and nutrient in shrublands, could hamper grass recovery in recently established exclosures. However, improvements in the grass seed bank and soil physical traits related to higher water infiltration could favor its late recovery, which is triggered by an extremely wet cycle after several years of the seasonal exclosure. Exclosure is a promising management strategy for degraded areas involving intermingled patches of forests and shrublands.
在半干旱的查科地区，湿季放牧可以使成熟和次生林斑块的草地迅速恢复，但在以灌丛为主的退化最严重的斑块中则不能。为了了解其不同恢复动态的原因，我们分析了森林斑块类型(成熟林= MF，次生林= SF，灌丛= S)和4年季节性封育(与连续放牧相比)对影响草地恢复的生物和非生物因子(植被结构、辐射、草种子库、凋落物和土壤性状)的影响。植被结构通过控制凋落物数量，控制土壤化学性状。随着森林退化程度的增加，凋落物质量(MF = 6260, SF = 5410, S = 1220 kg DM/ha)、土壤总有机质(MF = 5.1%， SF = 4.1%， S = 3.5%)和氮素(MF = 0.25%， SF = 0.22%， S = 0.18%)减少，土壤入射辐射(MF = 28%， SF = 41%， S = 52%)增加。经过4年的季节性放牧休息，我们发现所有森林斑块类型在0-10 cm和10-30 cm深度的土壤容重分别从1.13降低到1.07和1.07降低到1 g/cm3，总孔隙度分别从57增加到60和60增加到62%。封育还增加了森林(有草)和灌丛(甚至在草地恢复之前)的土壤种子库密度(从28个增加到251个/m2)，这些种子库将从相邻的森林斑块中接收种子，它们共存于同一景观基质中。我们的研究结果表明，低树木覆盖度、凋落物和土壤化学特征与低水分和养分有效性有关，可能阻碍最近建立的封地中草的恢复。然而，高水分入渗对草种子库和土壤物理性状的改善有利于其后期恢复，这是由数年季节性封育后的极湿循环引发的。对于森林和灌丛混杂的退化地区，围封是一种很有前途的管理策略。
{"title":"Forest degradation and short-term seasonal exclosure effects on biotic and abiotic factors linked to rangeland rehabilitation in semiarid Chaco, Argentina","authors":"S. Cotroneo, E. Jacobo, M. Brassiolo, R. Golluscio","doi":"10.1080/15324982.2021.1946206","DOIUrl":"https://doi.org/10.1080/15324982.2021.1946206","url":null,"abstract":"Abstract In semiarid Chaco, wet season grazing exclosures allow a rapid grass recovery in mature and secondary forest patches, but not in the most degraded patches dominated by shrublands. In order to understand the causes of their dissimilar rehabilitation dynamics, we analyzed the effects of the forest-patch type (mature forest = MF, secondary forest = SF, and shrubland = S) and 4-year seasonal exclosures (vs continuous grazing) on biotic and abiotic factors (vegetation structure, incident radiation, grass seed bank, litter and soil traits) that could affect grass recovery. We found that vegetation structure, through determining litter quantity, controlled soil chemical traits. As forest degradation level increased, litter mass (MF = 6260, SF = 5410, S = 1220 kg DM/ha), total soil organic matter (MF = 5.1%, SF = 4.1%, S = 3.5%) and nitrogen (MF = 0.25%, SF = 0.22%, S = 0.18%) decreased, and the incident radiation at soil level rose (MF = 28%, SF = 41%, S = 52%). After 4 years of seasonal grazing rest, we found reduced soil bulk density (from 1.13 to 1.07 and 1.07 to 1 g/cm3) and increased total porosity (from 57 to 60 and 60 to 62%) at 0–10 and 10–30 cm depth, respectively, in all forest patch types. Exclosure also increased soil seed bank density (from 28 to 251 grass seeds/m2) both in the forests (with grass) and in the shrublands (even before grass recovery), which would receive seeds from the adjacent forest patches, which coexist in the same landscape matrix. Our results suggest that the low tree cover, litter, and soil chemical traits related to lower availability of water and nutrient in shrublands, could hamper grass recovery in recently established exclosures. However, improvements in the grass seed bank and soil physical traits related to higher water infiltration could favor its late recovery, which is triggered by an extremely wet cycle after several years of the seasonal exclosure. Exclosure is a promising management strategy for degraded areas involving intermingled patches of forests and shrublands.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"35 1","pages":"47 - 66"},"PeriodicalIF":1.4,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89529841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-25DOI: 10.1080/15324982.2021.1943567
Salman Ahmad, M. Zaheer, H. Ali, K. O. Erinle, S. H. Wani, R. Iqbal, Okon Godwin Okone, A. Raza, M. Waqas, Muhammad Nawaz
Abstract In order to meet the dietary requirements of the rising human population with diminishing water resources, there is the need to adopt techniques that optimize crop yield under reduced water conditions. Therefore, a greenhouse experiment was carried out to determine the effect of mulching and reduced irrigation on wheat production. The experiment included four mulching treatments (un-mulched, black plastic sheet mulch, wheat straw mulch and cotton sticks mulch) and two watering regimes (normal watering and partial root-zone drying irrigation (PRI) technique that involves alternate watering to only one side of root zone only) arranged in a completely randomized design. Wheat growth (leaf area index, plant height), water related parameters (leaf relative water contents (RWC), leaf turgor potential and physiological (chlorophyll contents, stomatal oscillation and photosynthetic rate) parameters and biochemical indicators were significantly higher with mulching than un-mulched for both irrigation levels. However, among the mulching treatments, the use of black plastic mulch gave the best results. Among the mulch treatments, RWC increased by 4.29%, 7.50% and 10.73% with black plastic mulch compared to wheat straw mulch, cotton stick mulch and control treatment, respectively. Between the two irrigation levels, higher wheat growth, physiological and water related parameters were found with full irrigation. Whereas leaf osmotic potential, quality traits and antioxidant enzymatic activities were higher with PRI. This study shows that, particularly with black plastic film, mulching combined with partial root zone drying can be effectively used in conserving soil water, thus increasing crop water use, photosynthetic rate, and yield.
{"title":"Physiological and biochemical properties of wheat (Triticum aestivum L.) under different mulching and water management systems in the semi-arid region of Punjab, Pakistan","authors":"Salman Ahmad, M. Zaheer, H. Ali, K. O. Erinle, S. H. Wani, R. Iqbal, Okon Godwin Okone, A. Raza, M. Waqas, Muhammad Nawaz","doi":"10.1080/15324982.2021.1943567","DOIUrl":"https://doi.org/10.1080/15324982.2021.1943567","url":null,"abstract":"Abstract In order to meet the dietary requirements of the rising human population with diminishing water resources, there is the need to adopt techniques that optimize crop yield under reduced water conditions. Therefore, a greenhouse experiment was carried out to determine the effect of mulching and reduced irrigation on wheat production. The experiment included four mulching treatments (un-mulched, black plastic sheet mulch, wheat straw mulch and cotton sticks mulch) and two watering regimes (normal watering and partial root-zone drying irrigation (PRI) technique that involves alternate watering to only one side of root zone only) arranged in a completely randomized design. Wheat growth (leaf area index, plant height), water related parameters (leaf relative water contents (RWC), leaf turgor potential and physiological (chlorophyll contents, stomatal oscillation and photosynthetic rate) parameters and biochemical indicators were significantly higher with mulching than un-mulched for both irrigation levels. However, among the mulching treatments, the use of black plastic mulch gave the best results. Among the mulch treatments, RWC increased by 4.29%, 7.50% and 10.73% with black plastic mulch compared to wheat straw mulch, cotton stick mulch and control treatment, respectively. Between the two irrigation levels, higher wheat growth, physiological and water related parameters were found with full irrigation. Whereas leaf osmotic potential, quality traits and antioxidant enzymatic activities were higher with PRI. This study shows that, particularly with black plastic film, mulching combined with partial root zone drying can be effectively used in conserving soil water, thus increasing crop water use, photosynthetic rate, and yield.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"26 1","pages":"181 - 196"},"PeriodicalIF":1.4,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77585028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.1080/15324982.2021.1936689
Fariba Rasuli, H. Owliaie, M. Najafi-Ghiri, E. Adhami
Abstract Biochar as an eco-friendly substance, depending on its origin and production conditions, may have significant effects on soil properties, nutrient availability and K dynamics of arid and semi-arid soils. Biochars produced from wheat and corn residues, pyrolyzed at 250, 450 and 650 °C during 2, 4 and 8 h, were applied to four representative calcareous soils. First, 2 g of each biochar was added to 100 g of each soil and incubated under field capacity for 90 days. Then the soil samples were analyzed for soil properties, nutrient availability and K fractions. All biochars increased soil CEC, ECe and available K, P, Fe, Zn, Mn and Cu. The biochars produced at higher temperature had larger effect on soil properties, P and K availability, and smaller effect on Fe, Mn and Zn availability. The used biochars increased the amounts of soluble, exchangeable, non-exchangeable and HNO3-extractable K to 143–348, 316–605, 597–1,064 and 1,056–2,012 mg kg−1, respectively. The wheat biochar had larger effect on soil K than the corn biochar. Potassium saturation percentage increased with biochar application due to the larger effect of biochar on exchangeable K than CEC. The biochars increased the percentage of soluble K due to the limited capacity of exchange sites and clay interlayers for K adsorption. Biochar had different effect on the experimental soils; and the content of soluble K in the coarse-textured soils after biochar application increased more, than other K fractions. It was concluded that biochars, particularly the wheat biochar produced at higher temperature, have potential for improving K management of K depleted soils.
{"title":"Effect of biochar on potassium fractions and plant-available P, Fe, Zn, Mn and Cu concentrations of calcareous soils","authors":"Fariba Rasuli, H. Owliaie, M. Najafi-Ghiri, E. Adhami","doi":"10.1080/15324982.2021.1936689","DOIUrl":"https://doi.org/10.1080/15324982.2021.1936689","url":null,"abstract":"Abstract Biochar as an eco-friendly substance, depending on its origin and production conditions, may have significant effects on soil properties, nutrient availability and K dynamics of arid and semi-arid soils. Biochars produced from wheat and corn residues, pyrolyzed at 250, 450 and 650 °C during 2, 4 and 8 h, were applied to four representative calcareous soils. First, 2 g of each biochar was added to 100 g of each soil and incubated under field capacity for 90 days. Then the soil samples were analyzed for soil properties, nutrient availability and K fractions. All biochars increased soil CEC, ECe and available K, P, Fe, Zn, Mn and Cu. The biochars produced at higher temperature had larger effect on soil properties, P and K availability, and smaller effect on Fe, Mn and Zn availability. The used biochars increased the amounts of soluble, exchangeable, non-exchangeable and HNO3-extractable K to 143–348, 316–605, 597–1,064 and 1,056–2,012 mg kg−1, respectively. The wheat biochar had larger effect on soil K than the corn biochar. Potassium saturation percentage increased with biochar application due to the larger effect of biochar on exchangeable K than CEC. The biochars increased the percentage of soluble K due to the limited capacity of exchange sites and clay interlayers for K adsorption. Biochar had different effect on the experimental soils; and the content of soluble K in the coarse-textured soils after biochar application increased more, than other K fractions. It was concluded that biochars, particularly the wheat biochar produced at higher temperature, have potential for improving K management of K depleted soils.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"1 1","pages":"1 - 26"},"PeriodicalIF":1.4,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89784165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-08DOI: 10.1080/15324982.2021.1933648
Liangyan Yang, Zenghui Sun, Jianfeng Li, Lei Shi, Hui Kong, Yuan-zhou Yang, Tong Li
Abstract The understanding of land-use and land-cover change (LUCC) is crucial for the study of global climate change and the terrestrial ecological environment. Sandy land is an important component of the terrestrial ecosystem. This study applied the land-use transition matrix and change trajectory analysis to examine the spatiotemporal characteristics of LUCC from 1980 to 2018 in the Mu Us Sandy Land, China. The influences of soil, meteorological conditions, and national policy on LUCC in this region were also investigated. The results of land-use classification of five remote sensing images captured between 1980 and 2018 showed that Grassland was the dominant land-use type. The areas of Woodland and Built-up land in the study area continued to increase, whereas those of Water bodies and Unused land continued to decrease. The area of Cropland first increased and then decreased. The areas where LUCC was driven by natural factors and anthropogenic factors were 25,428 km2 and 9,683 km2, representing 27.92% and 10.63% of the total area, respectively. The area that experienced no LUCC was 55,950 km 2 (61.44% of the total area). These data showed that LUCC was driven by natural and anthropogenic factors, with anthropogenic factors dominant in driving changes in Cropland, Woodland, and Built-up land, whereas natural factors dominated reductions in the areas of Water bodies and Unused land. Although natural factors played an important role in LUCC, this study showed that anthropogenic factors determine the direction of LUCC.
{"title":"Spatiotemporal patterns and driving forces of land-use and land-cover change in the Mu Us Sandy Land, China from 1980 to 2018","authors":"Liangyan Yang, Zenghui Sun, Jianfeng Li, Lei Shi, Hui Kong, Yuan-zhou Yang, Tong Li","doi":"10.1080/15324982.2021.1933648","DOIUrl":"https://doi.org/10.1080/15324982.2021.1933648","url":null,"abstract":"Abstract The understanding of land-use and land-cover change (LUCC) is crucial for the study of global climate change and the terrestrial ecological environment. Sandy land is an important component of the terrestrial ecosystem. This study applied the land-use transition matrix and change trajectory analysis to examine the spatiotemporal characteristics of LUCC from 1980 to 2018 in the Mu Us Sandy Land, China. The influences of soil, meteorological conditions, and national policy on LUCC in this region were also investigated. The results of land-use classification of five remote sensing images captured between 1980 and 2018 showed that Grassland was the dominant land-use type. The areas of Woodland and Built-up land in the study area continued to increase, whereas those of Water bodies and Unused land continued to decrease. The area of Cropland first increased and then decreased. The areas where LUCC was driven by natural factors and anthropogenic factors were 25,428 km2 and 9,683 km2, representing 27.92% and 10.63% of the total area, respectively. The area that experienced no LUCC was 55,950 km 2 (61.44% of the total area). These data showed that LUCC was driven by natural and anthropogenic factors, with anthropogenic factors dominant in driving changes in Cropland, Woodland, and Built-up land, whereas natural factors dominated reductions in the areas of Water bodies and Unused land. Although natural factors played an important role in LUCC, this study showed that anthropogenic factors determine the direction of LUCC.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"144 1","pages":"109 - 124"},"PeriodicalIF":1.4,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76916621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-08DOI: 10.1080/15324982.2021.1936289
Slama Inès, O. Talbi, Yousfi Nasreddine, Aida Rouached, Jihed Gharred, Asma Jdey, M. Hanana, C. Abdelly
Abstract This review provides a comprehensive overview of the effects of drought on the growth of medic plants; then, it explores some drought tolerance traits including the morpho-physiological and biochemical parameters. In addition, medic plants were compared to other legumes and to cereals. At the molecular level, the response of Medicago plants to drought was also highlighted. Results of several independent experiments showed that the reduction of plant biomass production of medic plants ranged between 12 and 73% under water deficit stress. Cereals are more tolerant to drought than legumes. Yield reduction in cereals ranged between 25 and 40% versus 20 and 80% in legumes. For cereal species, wheat exhibited the lowest (25%) yield reduction as compared to barley and maize (34 and 40%), respectively. In legumes, reductions were about 20, 40, and 60% in lentils, chickpea, and common bean. Medic drought tolerance was found to be associated with traits like the ability to maintain the photosynthetic activity, the optimization of root development, the water use efficiency, the osmoregulation capacity via the decrease of osmotic potential, accumulation of mineral (K+) or organic solutes (proline), and the modification of carbohydrate metabolism toward the accumulation of soluble sugars. Water deficit stress induces a lipid and protein metabolism adaptation via the accumulation of some amino acids and the decrease in malondialdehyde concentrations. The target traits suggested in medic for breeding and for genetic engineering are related to water relations, such as relative water content, water use efficiency as well as root development.
{"title":"Drought tolerance traits in Medicago species: A review","authors":"Slama Inès, O. Talbi, Yousfi Nasreddine, Aida Rouached, Jihed Gharred, Asma Jdey, M. Hanana, C. Abdelly","doi":"10.1080/15324982.2021.1936289","DOIUrl":"https://doi.org/10.1080/15324982.2021.1936289","url":null,"abstract":"Abstract This review provides a comprehensive overview of the effects of drought on the growth of medic plants; then, it explores some drought tolerance traits including the morpho-physiological and biochemical parameters. In addition, medic plants were compared to other legumes and to cereals. At the molecular level, the response of Medicago plants to drought was also highlighted. Results of several independent experiments showed that the reduction of plant biomass production of medic plants ranged between 12 and 73% under water deficit stress. Cereals are more tolerant to drought than legumes. Yield reduction in cereals ranged between 25 and 40% versus 20 and 80% in legumes. For cereal species, wheat exhibited the lowest (25%) yield reduction as compared to barley and maize (34 and 40%), respectively. In legumes, reductions were about 20, 40, and 60% in lentils, chickpea, and common bean. Medic drought tolerance was found to be associated with traits like the ability to maintain the photosynthetic activity, the optimization of root development, the water use efficiency, the osmoregulation capacity via the decrease of osmotic potential, accumulation of mineral (K+) or organic solutes (proline), and the modification of carbohydrate metabolism toward the accumulation of soluble sugars. Water deficit stress induces a lipid and protein metabolism adaptation via the accumulation of some amino acids and the decrease in malondialdehyde concentrations. The target traits suggested in medic for breeding and for genetic engineering are related to water relations, such as relative water content, water use efficiency as well as root development.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"40 1","pages":"67 - 83"},"PeriodicalIF":1.4,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76718747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Annual total precipitation typically fails to predict litter decomposition rates, especially in semi-arid regions, where precipitation frequency (PF) significantly affects decomposition. We hypothesized that low PF would decrease decomposition rates. We performed a litterbag decomposition experiment with litter of three annual species at three depths (aboveground litter, litter at 0–10 and 10–20 cm below the surface). We used the same total amount (280 mm), but three precipitation frequencies (PF1, 10 mm every 5 days; PF2, 20 mm every 10 days; PF3, 40 mm every 20 days) during the growing season. We measured the remaining mass, carbon (C) content, nitrogen (N) content, C:N ratio, and C and N losses of each species at the three positions. Litter decomposition and the C and N dynamics were influenced by species, depth, and PF. Low PF significantly decreased litter decomposition (mass loss rates of 49.7, 49.1, and 41.2% for PF1, PF2, and PF3, respectively). This effect interacted with placement-depth but not with species. This interaction also existed for C and N dynamics except for the N loss rate. The influence of PF on C loss mainly resulted from its effect on mass loss, whereas N loss was not affected by PF. Our results highlight the importance of PF for litter decomposition in a semi-arid region. The relationship between PF and litter decomposition provides a theoretical basis for regional carbon-cycle models and carbon budget predictions. Our results also suggest that non-graminaceous species showed higher potential than grasses for improving soil carbon in semi-arid sandy grasslands due to faster decomposition rates, especially below ground.
{"title":"Effect of precipitation frequency on litter decomposition of three annual species (Setaria viridis, Artemisia sacrorum, and Chenopodium acuminatum) in a semi-arid sandy grassland of northeastern China","authors":"Yongqing Luo, Jing Zhou, Xiangfei Yue, Ji-Dong Ding","doi":"10.1080/15324982.2021.1921881","DOIUrl":"https://doi.org/10.1080/15324982.2021.1921881","url":null,"abstract":"Abstract Annual total precipitation typically fails to predict litter decomposition rates, especially in semi-arid regions, where precipitation frequency (PF) significantly affects decomposition. We hypothesized that low PF would decrease decomposition rates. We performed a litterbag decomposition experiment with litter of three annual species at three depths (aboveground litter, litter at 0–10 and 10–20 cm below the surface). We used the same total amount (280 mm), but three precipitation frequencies (PF1, 10 mm every 5 days; PF2, 20 mm every 10 days; PF3, 40 mm every 20 days) during the growing season. We measured the remaining mass, carbon (C) content, nitrogen (N) content, C:N ratio, and C and N losses of each species at the three positions. Litter decomposition and the C and N dynamics were influenced by species, depth, and PF. Low PF significantly decreased litter decomposition (mass loss rates of 49.7, 49.1, and 41.2% for PF1, PF2, and PF3, respectively). This effect interacted with placement-depth but not with species. This interaction also existed for C and N dynamics except for the N loss rate. The influence of PF on C loss mainly resulted from its effect on mass loss, whereas N loss was not affected by PF. Our results highlight the importance of PF for litter decomposition in a semi-arid region. The relationship between PF and litter decomposition provides a theoretical basis for regional carbon-cycle models and carbon budget predictions. Our results also suggest that non-graminaceous species showed higher potential than grasses for improving soil carbon in semi-arid sandy grasslands due to faster decomposition rates, especially below ground.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"20 1","pages":"397 - 413"},"PeriodicalIF":1.4,"publicationDate":"2021-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75424952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-05DOI: 10.1080/15324982.2021.1921071
M. Sawalhah, Y. Othman, A. A. Abu Yahya, S. Al-Kofahi, Fatima A. Al-Lataifeh, A. Cibils
Abstract To explore the effect of COVID-19 pandemic lockdown on vegetation cover changes in Northern, Middle, and Eastern Jordan Badia rangelands, Landsat-8 (Operational Land Imager [OLI]) images were downloaded and processed to attain surface reflectance data for March and July 2018–2020. Normalized difference vegetation index (NDVI) was then derived from OLI-images, where the total area covered with water, bare soil, scattered vegetation, dense grasses and shrubs, and dense forests were estimated. Across the study period, 2019 had the highest rainfall (195 mm) and temperature (21.7 °C), while the lowest rainfall was recorded in 2018 (154 mm). The Northern Badia showed a consistently larger area of dense vegetation on average (407.4 km2) compared to the Eastern (149.3km2), and Middle (55.2 km2) Badia. The total area covered with scattered vegetation in 2020 was higher than in 2019 and 2018 across the years and studied area, except in Middle Badia. Vegetation cover classes were inconsistent for Middle Badia in March, scattered vegetation was higher in 2019 compared to 2020. However, the total area covered with vegetation in July was lower than in March across the years and studied area. The curfew allowed the regeneration of shrubs and grasses in the study area, which helped in restoring the rangeland vegetation. COVID-19 lockdown served as a conservation grazing technique and provided a real case of restoring the degraded rangeland cover through managed grazing.
为探讨新冠肺炎疫情对约旦巴迪亚牧场北部、中部和东部植被覆盖变化的影响，下载Landsat-8 (Operational Land Imager [OLI])卫星图像并进行处理，获取2018-2020年3月和7月的地表反射率数据。然后，利用oli影像得到归一化植被指数(NDVI)，估算水体覆盖面积、裸土覆盖面积、植被分散覆盖面积、茂密草丛和灌木覆盖面积以及茂密森林覆盖面积。在整个研究期间，2019年的降雨量最高(195毫米)，气温最高(21.7°C)，而2018年的降雨量最低(154毫米)。巴迪亚北部平均植被密度为407.4 km2，高于东部(149.3km2)和中部(55.2 km2)。除中巴迪亚地区外，各年份和研究区域2020年散乱植被覆盖总面积均高于2019年和2018年。中巴迪亚3月植被覆盖等级不一致，2019年分散植被高于2020年。但各年份和研究区7月植被覆盖总面积均低于3月。宵禁使研究区域的灌木和草得以再生，这有助于恢复牧场植被。COVID-19封锁作为一种保护性放牧技术，提供了通过管理放牧恢复退化牧场覆盖的真实案例。
{"title":"Evaluating the influence of COVID-19 pandemic lockdown on Jordan Badia rangelands","authors":"M. Sawalhah, Y. Othman, A. A. Abu Yahya, S. Al-Kofahi, Fatima A. Al-Lataifeh, A. Cibils","doi":"10.1080/15324982.2021.1921071","DOIUrl":"https://doi.org/10.1080/15324982.2021.1921071","url":null,"abstract":"Abstract To explore the effect of COVID-19 pandemic lockdown on vegetation cover changes in Northern, Middle, and Eastern Jordan Badia rangelands, Landsat-8 (Operational Land Imager [OLI]) images were downloaded and processed to attain surface reflectance data for March and July 2018–2020. Normalized difference vegetation index (NDVI) was then derived from OLI-images, where the total area covered with water, bare soil, scattered vegetation, dense grasses and shrubs, and dense forests were estimated. Across the study period, 2019 had the highest rainfall (195 mm) and temperature (21.7 °C), while the lowest rainfall was recorded in 2018 (154 mm). The Northern Badia showed a consistently larger area of dense vegetation on average (407.4 km2) compared to the Eastern (149.3km2), and Middle (55.2 km2) Badia. The total area covered with scattered vegetation in 2020 was higher than in 2019 and 2018 across the years and studied area, except in Middle Badia. Vegetation cover classes were inconsistent for Middle Badia in March, scattered vegetation was higher in 2019 compared to 2020. However, the total area covered with vegetation in July was lower than in March across the years and studied area. The curfew allowed the regeneration of shrubs and grasses in the study area, which helped in restoring the rangeland vegetation. COVID-19 lockdown served as a conservation grazing technique and provided a real case of restoring the degraded rangeland cover through managed grazing.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"46 1","pages":"483 - 495"},"PeriodicalIF":1.4,"publicationDate":"2021-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75995860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-21DOI: 10.1080/15324982.2021.1905103
M. Waseem, S. Mumtaz, M. Hameed, S. Fatima, M. Ahmad, F. Ahmad, M. Ashraf, I. Ahmad
Abstract Forty-nine accessions were collected from arid and semi-arid areas of Pakistan to explore adaptive components in red-grained wheat (Triticum aestivum L.). Single-line selections of these accessions were grown on an arid and a control site; that is, Uchkera Farm (UF) and Botanical Garden (BG), Faisalabad. The accessions grown at BG exhibited significantly better biomass and grain yield production than those grown at UF. Accession Ck5 from Chakwal produced the maximum grain yield (17.7 g plant−1) at BG and Jm3 (8.1 g plant−1) at UF. Among the eight accessions selected for further anatomical studies, Dg2 showed increased yield per plant at UF, which was related to root modifications like increased cortical region thickness, endodermal cell area, vascular region thickness, metaxylem area, and root hair length. Stem modifications included increased vascular bundle area, phloem area and stomatal density, while leaves showed increased cuticle thickness, bulliform cell thickness, trichome density, and length. Increased stomatal density and area were also found. Accession Jm3 showed a decrease in yield at UF. Root modifications in Jm3 included increased epidermal cell area, sclerenchymatous thickness, endodermal cell area, and root hair length. Stem modifications in this accession included increased stem cellular region thickness and sclerenchymatous cell area. Leaves had increased abaxial epidermal cell area, trichome number and length, and abaxial stomatal density. In conclusion, morpho-anatomical characteristics varied greatly in the red-grained wheat accessions at both experimental sites that have potential for incorporation into breeding efforts for drought tolerance in modern wheat cultivars.
{"title":"Adaptive traits for drought tolerance in red-grained wheat (Triticum aestivum L.) landraces","authors":"M. Waseem, S. Mumtaz, M. Hameed, S. Fatima, M. Ahmad, F. Ahmad, M. Ashraf, I. Ahmad","doi":"10.1080/15324982.2021.1905103","DOIUrl":"https://doi.org/10.1080/15324982.2021.1905103","url":null,"abstract":"Abstract Forty-nine accessions were collected from arid and semi-arid areas of Pakistan to explore adaptive components in red-grained wheat (Triticum aestivum L.). Single-line selections of these accessions were grown on an arid and a control site; that is, Uchkera Farm (UF) and Botanical Garden (BG), Faisalabad. The accessions grown at BG exhibited significantly better biomass and grain yield production than those grown at UF. Accession Ck5 from Chakwal produced the maximum grain yield (17.7 g plant−1) at BG and Jm3 (8.1 g plant−1) at UF. Among the eight accessions selected for further anatomical studies, Dg2 showed increased yield per plant at UF, which was related to root modifications like increased cortical region thickness, endodermal cell area, vascular region thickness, metaxylem area, and root hair length. Stem modifications included increased vascular bundle area, phloem area and stomatal density, while leaves showed increased cuticle thickness, bulliform cell thickness, trichome density, and length. Increased stomatal density and area were also found. Accession Jm3 showed a decrease in yield at UF. Root modifications in Jm3 included increased epidermal cell area, sclerenchymatous thickness, endodermal cell area, and root hair length. Stem modifications in this accession included increased stem cellular region thickness and sclerenchymatous cell area. Leaves had increased abaxial epidermal cell area, trichome number and length, and abaxial stomatal density. In conclusion, morpho-anatomical characteristics varied greatly in the red-grained wheat accessions at both experimental sites that have potential for incorporation into breeding efforts for drought tolerance in modern wheat cultivars.","PeriodicalId":8380,"journal":{"name":"Arid Land Research and Management","volume":"13 1","pages":"414 - 445"},"PeriodicalIF":1.4,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82932379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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