Temperature In Grassland Research Articles

A global meta-analysis on the effects of organic and inorganic fertilization on grasslands and croplands.

A central role for nature-based solution is to identify optimal management practices to address environmental challenges, including carbon sequestration and biodiversity conservation. Inorganic fertilization increases plant aboveground biomass but often causes a tradeoff with plant diversity loss. It remains unclear, however, whether organic fertilization, as a potential nature-based solution, could alter this tradeoff by increasing aboveground biomass without plant diversity loss. Here we compile data from 537 experiments on organic and inorganic fertilization across grasslands and croplands worldwide to evaluate the responses of aboveground biomass, plant diversity, and soil organic carbon (SOC). Both organic and inorganic fertilization increase aboveground biomass by 56% and 42% relative to ambient, respectively. However, only inorganic fertilization decreases plant diversity, while organic fertilization increases plant diversity in grasslands with greater soil water content. Moreover, organic fertilization increases SOC in grasslands by 19% and 15% relative to ambient and inorganic fertilization, respectively. The positive effect of organic fertilization on SOC increases with increasing mean annual temperature in grasslands, a pattern not observed in croplands. Collectively, our findings highlight organic fertilization as a potential nature-based solution that can increase two ecosystem services of grasslands, forage production, and soil carbon storage, without a tradeoff in plant diversity loss.

Temperature sensitivity of soil-borne fungal phytopathogens depends on niche breadth and land use types

Soil-borne fungal plant pathogens pose great threats to agricultural productivity and native ecosystems. However, the roles of niche breadth and land-use types in regulating the response of soil-borne fungal plant pathogens to temperature changes largely remain unclear. Here, we surveyed soil pathogens from different valleys where croplands, grasslands, and woodlands scattered in mosaic patterns. We found that pathogen richness increased with increasing temperature in grasslands but not in croplands and woodlands. After classifying the pathogens based on temperature niche, we found that the richness of specialists was sensitive to temperature changes and increased with increasing temperature in grasslands and croplands. By contrast, the richness of neutrals (those taxa not defined as generalists or specialists) did not change with temperature gradients regardless of land-use types. Additionally, pathogens were more abundant and diverse in croplands than those in grasslands and woodlands, and this pattern persisted across the temperature gradient. Our results provide evidence that temperature change and land use types could additively affect the diversity of plant pathogens in soils. This work advances our understanding of how niche breadth affects the response of pathogens to temperature, highlighting the importance of climate change and land use in regulating the abundance and diversity of pathogens.

Climate and vegetation collectively drive soil respiration in montane forest-grassland landscapes of the southern Western Ghats, India

Abstract CO2 release rates from soils via soil respiration play an important role in the carbon budget of terrestrial ecosystems. Though the roles of soil temperature and moisture on soil respiration are well recognised, less is known about how their effects vary across different land-cover types. This study looked at the interactive effects of land-cover change and microclimate on temporal patterns of soil respiration in a montane forest-grassland-plantation mosaic in a highly diverse but climatically sensitive ecosystem in the tropical Western Ghats of India. Across all vegetation types, soil respiration rates were highest during south-west monsoon (June–October), when root growth, litter decomposition and microbial activity are relatively high and were lowest during the summer. Among vegetation types, soil respiration rates were higher in grasslands compared to non-native pine plantations, whereas that of forest and invasive wattle (Acacia mearnsii) plantations were intermediate between grasslands and pine plantations. The decline in respiration rates following conversion from grasslands to pine plantations could be due to relatively lower microbial activity, soil temperatures and, subsequently, slower litter decomposition. In addition, the sensitivity of soil respiration to changes in temperature and moisture differed between different vegetation types. Across all vegetation types, respiration was largely insensitive to changes in soil temperature when moisture levels were low. However, when soil moisture levels were high, respiration increased with temperature in grassland and wattle patches, decreased in the case of pine plantations and remained largely unchanged in shola forests. Our results suggest that changes in aboveground vegetation type can significantly affect soil C cycling even in the absence of any underlying differences in soil type.

Vegetation dynamics and their responses to climate factors in the Qinghai-Tibet plateau: insights from the terrestrial ecosystems

This study examined the structural changes of vegetation ecosystems, multi-scale cyclical variations of normalized difference vegetation index (NDVI), as well as their responses to climate factors in the QTP during 2001–2018. Results showed the annual increment of NDVI in forest ecosystem was the largest, followed by grassland, and the increment of NDVI in desert ecosystem was the smallest. Vegetation activities showed a steady upward trend in forest, grassland and desert ecosystems, a fluctuating upward trend in the wetland ecosystem, and a slow downward trend in the farmland ecosystem. The intra-annual cycles of vegetation activities in these ecosystems were between 28 and 42 days, and only the forest ecosystem had a clear inter-annual cycle of 2.1 years. The responses of NDVI to precipitation and temperature in grassland, wetland, and farmland ecosystems all had a lag time of 16 days, while those in desert and forest ecosystems were weak.

PHENOLOGY OF BUSH-FORAGE SPECIES ESTABLISHED IN A SILVOPASTORAL SYSTEM IN TWO SOIL TYPES IN YUCATAN, MEXICO

Silvopastoral systems represent a sustainable alternative for livestock production. Such systems are part of agroforestry and represent an agroecosystem which can be designed chronological and topological by an arboreal and herbaceous component. It has been demonstrated that silvopastoral systems can improve the forage production, add firewood and reduce temperature in grassland what generating animal wellness. However, to obtain the benefits of a silvopastoral system, it is important to know the phenology of forage bushes in a multi-associated system. The objective of this work was to evaluate a multi-associated silvopastoral system accord of the phenological behavior of four bushes with forage potential in two types of soil (Leptosol and Lithosol). The study was carried out in a plot of 130 x 25 m. Around the plot was intercalated Hibiscus rosa-sinensis(Tulipan)species at 25 cm between plant, Gliricidiasepium(Cocoite)and Guazumaulmifolia(Pixoy)at 2 m, and inside of the plot Leucaenaleucocephala(Huaxin) at 50 cmbetween plants and3 m between rows. Evaluated treatments were Leptosol or Lithosol soils, the variables measured were plant height, basal diameter, diameter at 35 cm, branches number, flowering date and pods number, growth rate and surviving. The analysis of variance and Duncan test were carried out to detect differences between treatments in plant age. The 100% of surviving was observed in Huaxin, Pixoy and Tulipan species in both soil types at 10,7 and 10 months of age respectively, furthermore, Cocoite showed 69 and 81 % of surviving in Leptosol and Lithosol soil respectively at the 6 months of transplant. Plant height of Huaxin at ten months of age was (P<0.05) 145.5±38.70 cm with growth rate (GR) of 0.66±0.19 cm d-1 in Leptosol soil and 138.2±46.71 cm for Lithosol with GR of 0.62±0.16 cm d-1. Flowering was in winter at 5 age months. Pods productions differences (P<0.05) were observed in Leptosol with 56.3±49.41 pods and in Lithosol with 45±43.74 pods. The growth rate of Pixoy at seven months of age was (P<0.05) 133.0±29.00 cm in Leptosol with 0.68±14 cm d-1 and 101.0±27.33 cm in Lithosol soil with 0.52±138 cm d-1. The highest Tulipan plants at ten mons age were (P<0.05) 163±36.10 cm with 0.68±0.12 cm d-1 of GR in Leptosol soil and 147.7±20.38 cm with 0.62±0.07 cm d-1 of GR in Lithosol soil. For all variables in soil treatment were detected differences (P<0.05), in which, Leptosol showed be the best soil for growth. Furthermore, this type soil showed positive influence in forage bushes growth due to plants showed the best growth, except Cocoite which the surviving rate was higher in Lithosol soil.

Daily temperature trend and sensitivity to grassland and cropland in eastern China during the past 32 years

In order to detect daily temperature trend in eastern China, observed daily temperature data spanning over 32 years (1979–2010) including daily maximum temperature (Tmax), minimum temperature (Tmin) and mean temperature (Tavg) were analysed. Besides, land cover conversions in grassland/cropland around 102 meteorological stations were also investigated to explore the sensitivity of temperature to grassland/cropland. Increasing trends were detected in observed Tmax and Tmin, with distinct connection to the distribution of grassland/cropland. Tmax changed greatly in grassland and Tmin in cropland. Besides, unique seasonal and spatial variability was discovered in Tmax and Tmin, respectively. Finally, percentile-based temperature indices derived from observed daily temperature data were further involved to demonstrate the sensitivity of temperature extremes to grassland/cropland, which showed that the annual occurrences of warm day, summer heat wave and winter warm night events were increasing, while those of cold night were decreasing. Analysis of thresholds that distinguished summer heat wave and winter warm night events suggested higher temperature in grassland.

Soil carbon accumulation after open-cast coal and oil shale mining in Northern Hemisphere: a quantitative review

Meta-analysis and other statistical methods were used to evaluate how changes in soil organic carbon (SOC) content in post-mining soils are related to different factors; the data were obtained from 17 studies covering 93 temperate post-mining sites in the Northern Hemisphere that had been revegetated by forest or grassland either by reclamation or natural succession. Because many studies have failed to report any measures of variance, only part of the data were used for meta-analysis. According to the meta-analysis, the rate of SOC accumulation was unrelated to vegetation type. In a separate analysis that included all available data and in which rates of SOC accumulation at each site were used as individual entries, the rate of SOC accumulation differed depending on the age of the site and vegetation type. Under deciduous forests, the rate reached a maximum after 5–10 years and then decreased. Under coniferous forests, the initial SOC values were lower than under deciduous forests, but slowly increased with age and reached a maximum after 30–40 years. No significant temporal trend was found in grasslands, probably because the data set included only relatively young grassland sites. Based on data from sites younger than 30 years, sites with grasslands and deciduous forests accumulated SOC faster than sites with coniferous forests. The rate of accumulation was negatively correlated with temperature under coniferous forests, but positively correlated with temperature in grasslands. This suggests that carbon sequestration is favored by cold climates in coniferous forests, but by warm climates in grasslands. Deciduous forests were intermediate. Compared to conifers, deciduous trees may support SOC sequestration deeper in the soil profile, which may enhance SOC stability. A large proportion of post-mining sites reach the pre-mining SOC stock within 20 years or less after reclamation.