Pub Date : 2025-12-22DOI: 10.1016/j.jaridenv.2025.105543
José Laurindo dos Santos Júnior , Guilherme Alcântara Matos , Elizamar Ciríaco da Silva
High temperature is a critical environmental factor that impacts seed bank persistence and limits recruitment, particularly hindering regeneration dynamics in arid and semi-arid ecosystems. Given global climate change, understanding how seeds respond to such conditions is crucial for ecosystem resilience and its capacity for natural regeneration. This study investigated how temporal exposure to high temperatures affects the germination and early growth of Sapindus saponaria L., a species found in the Caatinga ecosystem that contributes to seed bank formation. Seeds were exposed to high temperatures (70 °C) for 15, 45, 60, and 90 min, corresponding to the estimated soil surface temperatures and exposition times recorded during the peak solar irradiance period in semi-arid regions. Seed germination, seedling growth, and vigor were evaluated. Exposure of S. saponaria seeds to high temperatures for moderate durations (45 and 60 min) improved germination and seed vigor. Furthermore, seedlings exhibited greater vigor and vegetative growth. Moderate exposure to high temperatures may optimize germination and early seedling vigor in S. saponaria, potentially enhancing the recruitment of new individuals in warm environments.
{"title":"Inhibition or stimulation: effect of high temperature on the seed germination and vigor, and impacts on seedling growth of Sapindus saponaria L","authors":"José Laurindo dos Santos Júnior , Guilherme Alcântara Matos , Elizamar Ciríaco da Silva","doi":"10.1016/j.jaridenv.2025.105543","DOIUrl":"10.1016/j.jaridenv.2025.105543","url":null,"abstract":"<div><div>High temperature is a critical environmental factor that impacts seed bank persistence and limits recruitment, particularly hindering regeneration dynamics in arid and semi-arid ecosystems. Given global climate change, understanding how seeds respond to such conditions is crucial for ecosystem resilience and its capacity for natural regeneration. This study investigated how temporal exposure to high temperatures affects the germination and early growth of <em>Sapindus saponaria</em> L., a species found in the Caatinga ecosystem that contributes to seed bank formation. Seeds were exposed to high temperatures (70 °C) for 15, 45, 60, and 90 min, corresponding to the estimated soil surface temperatures and exposition times recorded during the peak solar irradiance period in semi-arid regions. Seed germination, seedling growth, and vigor were evaluated. Exposure of <em>S. saponaria</em> seeds to high temperatures for moderate durations (45 and 60 min) improved germination and seed vigor. Furthermore, seedlings exhibited greater vigor and vegetative growth. Moderate exposure to high temperatures may optimize germination and early seedling vigor in <em>S. saponaria</em>, potentially enhancing the recruitment of new individuals in warm environments.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105543"},"PeriodicalIF":2.5,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-22DOI: 10.1016/j.jaridenv.2025.105545
Etinosa Igunbor , Jennie DeMarco , Philip Crossley
Restored wet meadows and sagebrush in the western United States present unique challenges for soil organic carbon (SOC) prediction due to their topographic complexity and ecological heterogeneity. While remote sensing (RS) and machine learning (ML) have shown promise in SOC modeling, the influence of RS temporal averaging and terrain data (TD) on model performance remains poorly understood in these landscapes. This study compares four commonly used SOC prediction models; random forest (RF), generalized additive model (GAM), partial least squares regression (PLSR), and stepwise linear regression (SLR), using averaged RS-derived data alone and in combination with TD and evaluates how different RS averaging periods affect prediction accuracy. These models were applied to RS metrics averaging over 1-day, 3-year, and 5-year periods, in combination with TD covariates (slope, aspect, topographic position index, elevation). The GAM model using NDVI, GSI, and CI performed best (Sapinero 1-day, R2 = 0.44; Wolf Creek 3-year, R2 = 0.29), with accuracy improving when TD was included (Sapinero 5-year, R2 = 0.48; Wolf Creek 1-day, R2 = 0.49). We found that GAMs offer a more robust SOC prediction performance, particularly in complex, restored landscapes, particularly when longer-term averaged RS data is used. Hence, our results highlight that remote sensing can be a low cost and accurate tool for estimating SOC in sagebrush and wet meadow ecosystems within the arid ecosystems.
美国西部恢复的湿草甸和山艾树由于其地形复杂性和生态异质性,对土壤有机碳(SOC)预测提出了独特的挑战。虽然遥感(RS)和机器学习(ML)在SOC建模中显示出前景,但在这些景观中,RS时间平均和地形数据(TD)对模型性能的影响仍然知之甚少。本研究比较了四种常用的有机碳预测模型;随机森林(RF)、广义加性模型(GAM)、偏最小二乘回归(PLSR)和逐步线性回归(SLR),分别使用RS平均数据单独和结合TD,并评估不同RS平均周期对预测精度的影响。这些模型结合TD协变量(坡度、坡向、地形位置指数、高程),应用于1天、3年和5年期间的RS指标均值。采用NDVI、GSI和CI的GAM模型表现最佳(Sapinero 1天,R2 = 0.44; Wolf Creek 3年,R2 = 0.29),当纳入TD时准确性提高(Sapinero 5年,R2 = 0.48; Wolf Creek 1天,R2 = 0.49)。我们发现GAMs提供了更强大的SOC预测性能,特别是在复杂的恢复景观中,特别是当使用长期平均RS数据时。因此,我们的研究结果表明,在干旱生态系统中,遥感可以作为一种低成本和准确的工具来估算山艾树和湿草甸生态系统的有机碳。
{"title":"Remote sensing-based modeling of soil organic carbon in wet meadow and sagebrush ecosystems in semi-arid landscapes","authors":"Etinosa Igunbor , Jennie DeMarco , Philip Crossley","doi":"10.1016/j.jaridenv.2025.105545","DOIUrl":"10.1016/j.jaridenv.2025.105545","url":null,"abstract":"<div><div>Restored wet meadows and sagebrush in the western United States present unique challenges for soil organic carbon (SOC) prediction due to their topographic complexity and ecological heterogeneity. While remote sensing (RS) and machine learning (ML) have shown promise in SOC modeling, the influence of RS temporal averaging and terrain data (TD) on model performance remains poorly understood in these landscapes. This study compares four commonly used SOC prediction models; random forest (RF), generalized additive model (GAM), partial least squares regression (PLSR), and stepwise linear regression (SLR), using averaged RS-derived data alone and in combination with TD and evaluates how different RS averaging periods affect prediction accuracy. These models were applied to RS metrics averaging over 1-day, 3-year, and 5-year periods, in combination with TD covariates (slope, aspect, topographic position index, elevation). The GAM model using NDVI, GSI, and CI performed best (Sapinero 1-day, R<sup>2</sup> = 0.44; Wolf Creek 3-year, R<sup>2</sup> = 0.29), with accuracy improving when TD was included (Sapinero 5-year, R<sup>2</sup> = 0.48; Wolf Creek 1-day, R<sup>2</sup> = 0.49). We found that GAMs offer a more robust SOC prediction performance, particularly in complex, restored landscapes, particularly when longer-term averaged RS data is used. Hence, our results highlight that remote sensing can be a low cost and accurate tool for estimating SOC in sagebrush and wet meadow ecosystems within the arid ecosystems.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105545"},"PeriodicalIF":2.5,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dust storms pose significant environmental and health challenges in arid regions, necessitating accurate modeling for effective mitigation strategies. This study employed thirteen machine learning (MLs) and deep learning (DLs) models to identify dust-prone areas and evaluate the impact of various environmental drivers on dust storms. A set of variables, including evapotranspiration (ET), air temperature, land surface temperature, vegetation indices, mean precipitation (Pr), soil moisture, and six drought indices (Standardized Precipitation Index (SPI), Vegetation Health Index (VHI), Vegetation Condition Index (VCI), Temperature Condition Index (TCI), Soil Vegetation Index (SVI), and Palmer Drought Severity Index (PDSI)), was analyzed using Aerosol Optical Depth (AOD) as the target variable. The analysis revealed that tree-based MLs outperformed DLs in this study area, potentially due to the regional scale and dataset characteristics. Random Forest (RF) emerged as the most outstanding model, achieving exceptional accuracy in both regression (R2 > 0.96, RMSE = 0.01, MAE = 0.01) and classification tasks (Critical Success Index = 0.70, Recall = 0.76), along with a Bias value of 1.038 and 85 % overall accuracy in spatial detection of dust sources. Among DLs, Artificial Neural Network (ANN) showed competitive performance as a reliable alternative. Variable importance analysis identified temperature, precipitation, and ET as the most influential predictors, followed by soil moisture and PDSI. The findings provide a good framework for dust susceptibility mapping and highlight the advantage of tree-based MLs for dust modeling in regional-scale studies.
{"title":"Modeling dust storms using machine learning and deep learning techniques","authors":"Mohammad Kazemi , Marzieh Rezaei , Sedigheh Mousaei , Narges Kariminejad","doi":"10.1016/j.jaridenv.2025.105542","DOIUrl":"10.1016/j.jaridenv.2025.105542","url":null,"abstract":"<div><div>Dust storms pose significant environmental and health challenges in arid regions, necessitating accurate modeling for effective mitigation strategies. This study employed thirteen machine learning (MLs) and deep learning (DLs) models to identify dust-prone areas and evaluate the impact of various environmental drivers on dust storms. A set of variables, including evapotranspiration (ET), air temperature, land surface temperature, vegetation indices, mean precipitation (Pr), soil moisture, and six drought indices (Standardized Precipitation Index (SPI), Vegetation Health Index (VHI), Vegetation Condition Index (VCI), Temperature Condition Index (TCI), Soil Vegetation Index (SVI), and Palmer Drought Severity Index (PDSI)), was analyzed using Aerosol Optical Depth (AOD) as the target variable. The analysis revealed that tree-based MLs outperformed DLs in this study area, potentially due to the regional scale and dataset characteristics. Random Forest (RF) emerged as the most outstanding model, achieving exceptional accuracy in both regression (R<sup>2</sup> > 0.96, RMSE = 0.01, MAE = 0.01) and classification tasks (Critical Success Index = 0.70, Recall = 0.76), along with a Bias value of 1.038 and 85 % overall accuracy in spatial detection of dust sources. Among DLs, Artificial Neural Network (ANN) showed competitive performance as a reliable alternative. Variable importance analysis identified temperature, precipitation, and ET as the most influential predictors, followed by soil moisture and PDSI. The findings provide a good framework for dust susceptibility mapping and highlight the advantage of tree-based MLs for dust modeling in regional-scale studies.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105542"},"PeriodicalIF":2.5,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.jaridenv.2025.105546
Mia Brann , Karen Haubensak , Catherine Gehring , Sara Souther
Dryland managers face a dilemma balancing prescribed fire use with rare species conservation. In semi-arid grasslands and woodlands, managers often avoid burning habitats with threatened plants, though fire may reduce competition from invasive grasses and support native persistence. In the Madrean Sky Islands of southeastern Arizona, drought, altered fire regimes, and non-native species encroachment are transforming lower elevation grasslands and woodlands, home to the endangered forb, Pectis imberbis. These stressors interact in complex ways, yet cumulative effects on rare species like P. imberbis remain poorly understood. We conducted a fully factorial greenhouse experiment to test how fire, drought, and competition affect P. imberbis. Plants were grown from seed with intra- and interspecific competitors, then exposed to fire and drought. After 39 weeks, we measured above- and belowground biomass. Interspecific competition and drought reduced biomass, but burning appeared to ameliorate interspecific competition's negative effects. Pectis imberbis resprouted robustly after fire—even under drought and competition—though drought and intraspecific competition delayed resprouting. Our findings indicate prescribed fire may provide a safe and effective way to manage P. imberbis habitat while supporting broader goals such as invasive species control.
{"title":"Fire resilience and altered competitive dynamics of the endangered forb Pectis imberbis show potential for prescribed fire as a conservation tool","authors":"Mia Brann , Karen Haubensak , Catherine Gehring , Sara Souther","doi":"10.1016/j.jaridenv.2025.105546","DOIUrl":"10.1016/j.jaridenv.2025.105546","url":null,"abstract":"<div><div>Dryland managers face a dilemma balancing prescribed fire use with rare species conservation. In semi-arid grasslands and woodlands, managers often avoid burning habitats with threatened plants, though fire may reduce competition from invasive grasses and support native persistence. In the Madrean Sky Islands of southeastern Arizona, drought, altered fire regimes, and non-native species encroachment are transforming lower elevation grasslands and woodlands, home to the endangered forb, <em>Pectis imberbis</em>. These stressors interact in complex ways, yet cumulative effects on rare species like <em>P. imberbis</em> remain poorly understood. We conducted a fully factorial greenhouse experiment to test how fire, drought, and competition affect <em>P. imberbis</em>. Plants were grown from seed with intra- and interspecific competitors, then exposed to fire and drought. After 39 weeks, we measured above- and belowground biomass. Interspecific competition and drought reduced biomass, but burning appeared to ameliorate interspecific competition's negative effects. <em>Pectis imberbis</em> resprouted robustly after fire—even under drought and competition—though drought and intraspecific competition delayed resprouting. Our findings indicate prescribed fire may provide a safe and effective way to manage <em>P. imberbis</em> habitat while supporting broader goals such as invasive species control.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105546"},"PeriodicalIF":2.5,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1016/j.jaridenv.2025.105544
Thamara Fariñas-Torres , Eliana F. Burgos , Maria A. Chemisquy
The province of La Rioja is one of the most neglected regarding the knowledge of its biological diversity, and particularly the study of the mammals in the Sierra de Velasco has been reduced to a few articles. This paper aims to study the richness and distribution of the small mammals of the Sierra de Velasco and the environmental factors that influence the assemblage in an environmental gradient. Samplings were made with Sherman-like traps for 9330 trap nights. For the analysis of assemblage variation, an environmental gradient was established based on several characteristics, and three types of environments were delimited: Ravines, Shrublands, and Rocky fields. Alpha and beta diversity were calculated using Hills numbers, and species richness correlation with environmental variables associations was evaluated. Small mammal species richness was up to seven and was higher in the shrublands environment decreasing towards the extremes of the gradient, with the lowest richness found in the rocky fields’ environment. The richness was mainly correlated to variations in the average elevation of the sampling sites. This is an initial approach to understanding the relationships between small rodent species and environmental variations present in the arid mountains of the Sierra de Velasco.
{"title":"Small rodent assemblage variation across a mountain gradient in an arid region of northwestern Argentina","authors":"Thamara Fariñas-Torres , Eliana F. Burgos , Maria A. Chemisquy","doi":"10.1016/j.jaridenv.2025.105544","DOIUrl":"10.1016/j.jaridenv.2025.105544","url":null,"abstract":"<div><div>The province of La Rioja is one of the most neglected regarding the knowledge of its biological diversity, and particularly the study of the mammals in the Sierra de Velasco has been reduced to a few articles. This paper aims to study the richness and distribution of the small mammals of the Sierra de Velasco and the environmental factors that influence the assemblage in an environmental gradient. Samplings were made with Sherman-like traps for 9330 trap nights. For the analysis of assemblage variation, an environmental gradient was established based on several characteristics, and three types of environments were delimited: Ravines, Shrublands, and Rocky fields. Alpha and beta diversity were calculated using Hills numbers, and species richness correlation with environmental variables associations was evaluated. Small mammal species richness was up to seven and was higher in the shrublands environment decreasing towards the extremes of the gradient, with the lowest richness found in the rocky fields’ environment. The richness was mainly correlated to variations in the average elevation of the sampling sites. This is an initial approach to understanding the relationships between small rodent species and environmental variations present in the arid mountains of the Sierra de Velasco.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105544"},"PeriodicalIF":2.5,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.jaridenv.2025.105529
Juma Ayoub Tegeje , Msafiri Yusuph Mkonda , Zarah Pattison , Charles Joseph Kilawe
There is a limited information on the effects of Neltuma spp. on herbaceous species. This study assessed the effects of Neltuma spp. on herbaceous species in the drylands of northern Tanzania in 250 sampling quadrats established in the invaded and uninvaded areas. In each quadrat, information on herbaceous species composition, abundance, basal cover, and diversity was collected and compared between the two areas using Generalized Linear Mixed Models. Non-metric Multidimensional Scaling and Indicator Species analyses were applied to visualize patterns in species composition and identify species significantly associated with invaded and uninvaded areas, respectively. Results revealed that herbaceous species abundance, basal cover, and diversity were significantly (p < 0.001) lower in invaded areas compared to uninvaded areas. Soil moisture had a significant (p < 0.05) positive effect on herbaceous species. Species composition differed substantially between invaded and uninvaded areas. Digitaria velutina, Eragrostis superba, Eriochloa fatmensis, Pennisetum mezianum, and Indigofera atriceps were indicators of uninvaded areas, while Tragia insuavis was the indicator of invaded areas. Indicator species from uninvaded areas provide important socio-economic benefits. The continuing spread of Neltuma spp. threatens the sustainability of these benefits, calling for targeted management to curb their spread and preserve ecosystem functions in affected drylands.
{"title":"The invasion by Neltuma spp. changes herbaceous vegetation communities in Northern Tanzania","authors":"Juma Ayoub Tegeje , Msafiri Yusuph Mkonda , Zarah Pattison , Charles Joseph Kilawe","doi":"10.1016/j.jaridenv.2025.105529","DOIUrl":"10.1016/j.jaridenv.2025.105529","url":null,"abstract":"<div><div>There is a limited information on the effects of <em>Neltuma</em> spp. on herbaceous species. This study assessed the effects of <em>Neltuma</em> spp<em>.</em> on herbaceous species in the drylands of northern Tanzania in 250 sampling quadrats established in the invaded and uninvaded areas. In each quadrat, information on herbaceous species composition, abundance, basal cover, and diversity was collected and compared between the two areas using Generalized Linear Mixed Models. Non-metric Multidimensional Scaling and Indicator Species analyses were applied to visualize patterns in species composition and identify species significantly associated with invaded and uninvaded areas, respectively. Results revealed that herbaceous species abundance, basal cover, and diversity were significantly (<em>p</em> < 0.001) lower in invaded areas compared to uninvaded areas. Soil moisture had a significant (<em>p</em> < 0.05) positive effect on herbaceous species. Species composition differed substantially between invaded and uninvaded areas. <em>Digitaria velutina, Eragrostis superba, Eriochloa fatmensis, Pennisetum mezianum</em>, and <em>Indigofera atriceps</em> were indicators of uninvaded areas, while <em>Tragia insuavis</em> was the indicator of invaded areas. Indicator species from uninvaded areas provide important socio-economic benefits. The continuing spread of <em>Neltuma</em> spp. threatens the sustainability of these benefits, calling for targeted management to curb their spread and preserve ecosystem functions in affected drylands.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105529"},"PeriodicalIF":2.5,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-09DOI: 10.1016/j.jaridenv.2025.105541
Fujin Xu , Junchen Long , Changchun Xu
Accurate quantification of ecosystem carbon fixation is essential for carbon accounting and climate governance. However, the limited temporal coverage of remote sensing observations introduces substantial uncertainty in vegetation carbon sink estimates. Identifying errors and their drivers when extrapolating instantaneous to daily gross primary production (GPP) is therefore critical. Here, we used observations from 28 eddy covariance flux sites across major ecosystems in China to estimate instantaneous GPP at six local times (07:30–17:30 at 2 h intervals). Daily GPP was then derived from these instantaneous estimates using a cosine solar zenith angle [cos(SZA)]-based upscaling approach. A hybrid analytical framework combining triple collocation with in situ measurements was applied to evaluate the accuracy of these daily estimates. Results indicate that (1) extrapolation errors exhibit strong diurnal phase dependence, being lowest near noon (R ≈ 0.83, RMSE ≈ 1.26 gC m−2 d−1) but significantly higher during morning and evening (R ≈ 0.61, RMSE ≈ 2.34 gC m−2 d−1), reflecting nonlinear photosynthetic responses to photosynthetically active radiation; (2) grasslands consistently show lower errors than forests and other high-productivity ecosystems, highlighting ecosystem effects on accuracy; and (3) near noon, photosynthetic midday depression causes systematic underestimation (mostly within ±20 %, −356.3 to 52.7 tC km−2 yr−1), whereas morning and evening estimates show both underestimation and overestimation with much larger deviations (up to −1249.8 to 929.9 tC km−2 yr−1, often > ±50 %). In contrast to previous studies that are limited to qualitative analyses of single time periods or ecosystems, this study systematically characterized diurnal- and ecosystem-dependent error patterns in GPP extrapolation, clarifying cos(SZA)-based upscaling limitations. Findings emphasize the importance of scheduling satellite overpasses near solar noon and integrating ecological heterogeneity and stress factors into algorithms to improve accuracy and support reliable carbon sink assessments.
{"title":"Quantifying the accuracy of cos(SZA)-based upscaling from instantaneous to daily GPP: Implications for improving satellite-based SIF and GPP retrievals","authors":"Fujin Xu , Junchen Long , Changchun Xu","doi":"10.1016/j.jaridenv.2025.105541","DOIUrl":"10.1016/j.jaridenv.2025.105541","url":null,"abstract":"<div><div>Accurate quantification of ecosystem carbon fixation is essential for carbon accounting and climate governance. However, the limited temporal coverage of remote sensing observations introduces substantial uncertainty in vegetation carbon sink estimates. Identifying errors and their drivers when extrapolating instantaneous to daily gross primary production (GPP) is therefore critical. Here, we used observations from 28 eddy covariance flux sites across major ecosystems in China to estimate instantaneous GPP at six local times (07:30–17:30 at 2 h intervals). Daily GPP was then derived from these instantaneous estimates using a cosine solar zenith angle [cos(SZA)]-based upscaling approach. A hybrid analytical framework combining triple collocation with in situ measurements was applied to evaluate the accuracy of these daily estimates. Results indicate that (1) extrapolation errors exhibit strong diurnal phase dependence, being lowest near noon (R ≈ 0.83, RMSE ≈ 1.26 gC m<sup>−2</sup> d<sup>−1</sup>) but significantly higher during morning and evening (R ≈ 0.61, RMSE ≈ 2.34 gC m<sup>−2</sup> d<sup>−1</sup>), reflecting nonlinear photosynthetic responses to photosynthetically active radiation; (2) grasslands consistently show lower errors than forests and other high-productivity ecosystems, highlighting ecosystem effects on accuracy; and (3) near noon, photosynthetic midday depression causes systematic underestimation (mostly within ±20 %, −356.3 to 52.7 tC km<sup>−2</sup> yr<sup>−1</sup>), whereas morning and evening estimates show both underestimation and overestimation with much larger deviations (up to −1249.8 to 929.9 tC km<sup>−2</sup> yr<sup>−1</sup>, often > ±50 %). In contrast to previous studies that are limited to qualitative analyses of single time periods or ecosystems, this study systematically characterized diurnal- and ecosystem-dependent error patterns in GPP extrapolation, clarifying cos(SZA)-based upscaling limitations. Findings emphasize the importance of scheduling satellite overpasses near solar noon and integrating ecological heterogeneity and stress factors into algorithms to improve accuracy and support reliable carbon sink assessments.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105541"},"PeriodicalIF":2.5,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-09DOI: 10.1016/j.jaridenv.2025.105540
Paul Juan Jacobs , Daniel William Hart , Jennifer U.M. Jarvis , Nigel Charles Bennett
Cooperative behaviour presents an evolutionary paradox because although dispersal may increase direct fitness, many individuals forego reproduction to assist others. In arid-dwelling subterranean mammals, the high energetic costs of underground foraging, together with scarce and patchily distributed food resources are thought to have favoured the evolution of group living and cooperative breeding. These social systems are believed to enhance foraging efficiency and improve the survival prospects of individuals and groups. Using a longitudinal dataset from a wild population of Damaraland mole-rats (Fukomys damarensis) in arid central Namibia, we examine how group size predicts survival and persistence at both the individual and group levels. Our findings show that larger groups confer significant apparent survival benefits, that is the probability that an individual survives and remains available for recapture or resighting, reflecting both true survival and site fidelity, and also enhance colony persistence relative to solitary animals or pairs. We further demonstrate that these very small social-unit states are inherently unstable as without increases in group size, they are unlikely to persist within the population for extended periods. Larger groups clearly enhance survival, making remaining in the natal colony more beneficial than dispersing in an arid environment where dispersal is highly risky.
{"title":"Strength in numbers: Group size enhances individual survival and colony longevity in Damaraland mole-rats Fukomys damarensis","authors":"Paul Juan Jacobs , Daniel William Hart , Jennifer U.M. Jarvis , Nigel Charles Bennett","doi":"10.1016/j.jaridenv.2025.105540","DOIUrl":"10.1016/j.jaridenv.2025.105540","url":null,"abstract":"<div><div>Cooperative behaviour presents an evolutionary paradox because although dispersal may increase direct fitness, many individuals forego reproduction to assist others. In arid-dwelling subterranean mammals, the high energetic costs of underground foraging, together with scarce and patchily distributed food resources are thought to have favoured the evolution of group living and cooperative breeding. These social systems are believed to enhance foraging efficiency and improve the survival prospects of individuals and groups. Using a longitudinal dataset from a wild population of Damaraland mole-rats (<em>Fukomys damarensis</em>) in arid central Namibia<em>,</em> we examine how group size predicts survival and persistence at both the individual and group levels. Our findings show that larger groups confer significant apparent survival benefits, that is the probability that an individual survives and remains available for recapture or resighting, reflecting both true survival and site fidelity, and also enhance colony persistence relative to solitary animals or pairs. We further demonstrate that these very small social-unit states are inherently unstable as without increases in group size, they are unlikely to persist within the population for extended periods. Larger groups clearly enhance survival, making remaining in the natal colony more beneficial than dispersing in an arid environment where dispersal is highly risky.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105540"},"PeriodicalIF":2.5,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.jaridenv.2025.105528
Arthur Kolling Neto , Rayssa Balieiro Ribeiro , Fernando Falco Pruski
The use of spatial data can enable the estimation of water availability in semi-arid regions with limited monitoring. This study evaluated regionalization models of long-term mean streamflow in the Paraguaçu river basin, Bahia state, using explanatory variables derived from measured data and spatial products of precipitation and actual evapotranspiration from TerraClimate. The potential model was fitted using multiple regression and evaluated through statistical, physical, and risk analyses. Long-term mean streamflow (Qmlt) was estimated by univariate potential regionalization in hydrologically homogeneous sub-basins of the Paraguaçu river, comparing predictors based on drainage area (A), equivalent precipitation (Peq), and water balance (WB = P−AET) derived from observed data and spatial products (TerraClimate). Leave-one-station-out (LOSO) validation and a physical–hydrological verification via runoff coefficient along the river network indicated that A tends to overestimate flows in semiarid sectors; Peq improves the fit but ignores evapotranspiration losses; the spatial WB achieved the best overall performance and greater physical consistency. The model with entirely spatial WB showed the best results and the lowest hydrological risk for extrapolation. The approach, using open data and tools, is reproducible and useful for management in regions with sparse monitoring.
{"title":"Using spatial water balance to regionalize long-term mean streamflow in a data-scarce Brazilian semi-arid basin","authors":"Arthur Kolling Neto , Rayssa Balieiro Ribeiro , Fernando Falco Pruski","doi":"10.1016/j.jaridenv.2025.105528","DOIUrl":"10.1016/j.jaridenv.2025.105528","url":null,"abstract":"<div><div>The use of spatial data can enable the estimation of water availability in semi-arid regions with limited monitoring. This study evaluated regionalization models of long-term mean streamflow in the Paraguaçu river basin, Bahia state, using explanatory variables derived from measured data and spatial products of precipitation and actual evapotranspiration from TerraClimate. The potential model was fitted using multiple regression and evaluated through statistical, physical, and risk analyses. Long-term mean streamflow (Q<sub>mlt</sub>) was estimated by univariate potential regionalization in hydrologically homogeneous sub-basins of the Paraguaçu river, comparing predictors based on drainage area (A), equivalent precipitation (Peq), and water balance (WB = P−AET) derived from observed data and spatial products (TerraClimate). Leave-one-station-out (LOSO) validation and a physical–hydrological verification via runoff coefficient along the river network indicated that A tends to overestimate flows in semiarid sectors; Peq improves the fit but ignores evapotranspiration losses; the spatial WB achieved the best overall performance and greater physical consistency. The model with entirely spatial WB showed the best results and the lowest hydrological risk for extrapolation. The approach, using open data and tools, is reproducible and useful for management in regions with sparse monitoring.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105528"},"PeriodicalIF":2.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1016/j.jaridenv.2025.105532
Daniel Semedo , Diogo C. Pavão , Lurdes Borges Silva , Guilherme Roxo , Roberto Resendes , Maria Romeiras , Mónica Moura , Luís Silva
Neltuma juliflora (syn. Prosopis juliflora) is the dominant woody species in Cabo Verde, introduced through extensive reforestation efforts to combat land degradation. Despite its ecological and socio-economic relevance, little is known about its growth dynamics and climatic sensitivity in this region. This study investigates growth ring formation and climate–growth relationships of N. juliflora on Santiago Island. We sampled 165 trees across 11 blocks, grouped into four bioclimatic zones. Tree-ring widths were measured using standard dendrochronological techniques. Generalised Linear Models (GLMs) were applied to assess the influence of climatic variables, with multicollinearity controlled using the Variance Inflation Factor (VIF). Although false rings were present, distinct growth boundaries were observed. Mean radial growth varied from 1.53 to 2.11 mm/year across bioclimatic zones. The best GLMs suggest that higher precipitation outside of the usual rainy season could negatively affect growth, while mean annual temperature could have a marginally positive effect. Significant differences in tree-ring growth rate were observed between trees sampled at the four bioclimatic areas, likely reflecting the influence of climate and elevation, and of other factors such as soil and tree density. These results highlight the ecological plasticity of N. juliflora and support its potential use in dendroclimatic research in semi-arid tropical regions. These findings have significant implications for ecosystem-based adaptation strategies and sustainable land management practices in Cabo Verde, particularly in the context of climate change and land degradation mitigation. The study underscores the need for longer chronologies and expanded geographic sampling across the archipelago in future work.
{"title":"Climate-growth relationships in the introduced dominant woody tree Neltuma juliflora in Santiago Island, Cabo Verde Archipelago (Eastern Atlantic)","authors":"Daniel Semedo , Diogo C. Pavão , Lurdes Borges Silva , Guilherme Roxo , Roberto Resendes , Maria Romeiras , Mónica Moura , Luís Silva","doi":"10.1016/j.jaridenv.2025.105532","DOIUrl":"10.1016/j.jaridenv.2025.105532","url":null,"abstract":"<div><div><em>Neltuma juliflora</em> (syn. <em>Prosopis juliflora</em>) is the dominant woody species in Cabo Verde, introduced through extensive reforestation efforts to combat land degradation. Despite its ecological and socio-economic relevance, little is known about its growth dynamics and climatic sensitivity in this region. This study investigates growth ring formation and climate–growth relationships of <em>N. juliflora</em> on Santiago Island. We sampled 165 trees across 11 blocks, grouped into four bioclimatic zones. Tree-ring widths were measured using standard dendrochronological techniques. Generalised Linear Models (GLMs) were applied to assess the influence of climatic variables, with multicollinearity controlled using the Variance Inflation Factor (VIF). Although false rings were present, distinct growth boundaries were observed. Mean radial growth varied from 1.53 to 2.11 mm/year across bioclimatic zones. The best GLMs suggest that higher precipitation outside of the usual rainy season could negatively affect growth, while mean annual temperature could have a marginally positive effect. Significant differences in tree-ring growth rate were observed between trees sampled at the four bioclimatic areas, likely reflecting the influence of climate and elevation, and of other factors such as soil and tree density. These results highlight the ecological plasticity of <em>N. juliflora</em> and support its potential use in dendroclimatic research in semi-arid tropical regions. These findings have significant implications for ecosystem-based adaptation strategies and sustainable land management practices in Cabo Verde, particularly in the context of climate change and land degradation mitigation<strong>.</strong> The study underscores the need for longer chronologies and expanded geographic sampling across the archipelago in future work.</div></div>","PeriodicalId":51080,"journal":{"name":"Journal of Arid Environments","volume":"233 ","pages":"Article 105532"},"PeriodicalIF":2.5,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}