| 1. |
- Broberg, Malin, 1989, et al.
(författare)
-
Effects of ozone, drought and heat stress on wheat yield and grain quality
- 2023
-
Ingår i: Agriculture, Ecosystems & Environment. - 0167-8809. ; 352:15
-
Tidskriftsartikel (refereegranskat)abstract
- Tropospheric ozone (O3) is a gaseous phytotoxic plant stressor known to reduce wheat (Triticum aestivum) crop yields at current concentrations. O3 is predicted to increase in many crop-growing regions, together with higher frequencies of heatwaves and droughts. In this study, wheat crops were exposed to two levels of O3 (ambient and ~70 ppb) in combination with ambient or elevated temperature (+8 ◦C) and two watering regimes (well-watered and 50% reduced water supply) during the grain-filling period. With this experimental setup, we assessed the interactive effects between O3, temperature and water supply on wheat yield and grain quality, and measured leaf gas exchange to explore the underlying mechanisms. Overall, O3, warming and drought all decreased grain yield and average grain mass but increased grain concentration of N and other nutrient elements. Increasing daytime O3 from 25 to 73 ppb resulted in a 25% yield reduction in treatments with ambient temperature and well-watered soil. Drought reduced the impact of O3 on light-saturated photosynthesis, grain mass, total aboveground biomass and grain concentrations of K, Ca, Mg, Mo. In contrast, concentrations of K and Ca increased to a larger extent when O3 stress was combined with elevated temperature. Grain concentrations of N, Ca and Zn were closely and negatively related to grain yield regardless of O3, heat and drought stress, likely explained by the reduction in grain filling period, with starch accumulation reduced to a larger extent than that of these elements. P, K, Mg, Mn, Mo concentrations were weakly related to grain yield, but were clearly altered by environmental stress. The modifying effect of water availability is crucial to include in assessments of O3 impacts on global food production in relation to climate change, considering effects on wheat yield variables and grain nutrient concentrations.
|
|
| 2. |
- Harmens, Harry, et al.
(författare)
-
Temporal trends (1990-2000) in the concentration of cadmium, lead and mercury in mosses across Europe
- 2008
-
Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 151:2, s. 368-376
-
Tidskriftsartikel (refereegranskat)abstract
- The European heavy metals in mosses survey provides data on the concentration of 10 heavy metals in naturally growing mosses. The survey has been repeated at five-yearly intervals and in this paper we report on the temporal trends in the concentration of cadmium, lead and mercury between 1990 and 2000. Metal- and country-specific temporal trends were observed. In general, the concentration of lead and cadmium in mosses decreased between 1990 and 2000; the decline was higher for lead than cadmium. For mercury not enough data were available to establish temporal trends between 1990 and 1995, but between 1995 and 2000 the mercury concentration in mosses did not change across Europe. The observed temporal trends for the concentrations in mosses were similar to the trends reported for the modelled total deposition of cadmium, lead and mercury in Europe. (c) 2007 Elsevier Ltd. All rights reserved.
|
|
| 3. |
- Harmens, Harry, et al.
(författare)
-
Temporal trends in the concentration of arsenic, chromium, copper, iron, nickel, vanadium and zinc in mosses across Europe
- 2007
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 41:31, s. 6673-6687
-
Tidskriftsartikel (refereegranskat)abstract
- The European heavy metals in mosses biomonitoring network provides data on the concentration of 10 heavy metals in naturally growing mosses and is currently coordinated by the UNECE ICP Vegetation (United Nations Economic Commission for Europe International Co-operative Programme on Effects of Air Pollution on Natural Vegetation and Crops). The technique of moss analysis provides a surrogate, time-integrated measure of metal deposition from the atmosphere to terrestrial systems. It is easier and cheaper, less prone to contamination and allows a much higher sampling density than conventional precipitation analysis. Moss surveys have been repeated at five-yearly intervals and in this paper we report on the temporal trends in the concentration of arsenic, chromium, copper, iron, nickel, vanadium and zinc between 1990 and 2000. Maps were produced of the metal concentration in mosses for 1990, 1995 and 2000, showing the mean concentration per metal per 50 km x 50 km EMEP grid square. Metal- and country-specific temporal trends were observed. Although the metal concentration in mosses generally decreased with time for all metals, only the decreases for arsenic, copper, vanadium and zinc were statistically significant. The observed temporal trends were compared with emission trends for Europe reported by EMEP (Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutant in Europe).
|
|
| 4. |
- Komatsu, Kimberly J., et al.
(författare)
-
Global change effects on plant communities are magnified by time and the number of global change factors imposed
- 2019
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:36, s. 17867-17873
-
Tidskriftsartikel (refereegranskat)abstract
- Accurate prediction of community responses to global change drivers (GCDs) is critical given the effects of biodiversity on ecosystem services. There is consensus that human activities are driving species extinctions at the global scale, but debate remains over whether GCDs are systematically altering local communities worldwide. Across 105 experiments that included over 400 experimental manipulations, we found evidence for a lagged response of herbaceous plant communities to GCDs caused by shifts in the identities and relative abundances of species, often without a corresponding difference in species richness. These results provide evidence that community responses are pervasive across a wide variety of GCDs on long-term temporal scales and that these responses increase in strength when multiple GCDs are simultaneously imposed.Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.
|
|
| 5. |
- Mills, Gina, et al.
(författare)
-
Evidence of widespread effects of ozone on crops and (semi-)natural vegetation in Europe (1990 - 2006) in relation to AOT40 - and flux-based risk maps
- 2010
-
Ingår i: Global Change Biology. - : Wiley. - 1365-2486 .- 1354-1013. ; 17:1, s. 592-613
-
Tidskriftsartikel (refereegranskat)abstract
- Records of effects of ambient ozone pollution on vegetation have been compiled for Europe for the years 1990–2006. Sources include scientific papers, conference proceedings, reports to research funders, records of confirmed ozone injury symptoms and an international biomonitoring experiment coordinated by the ICP Vegetation. The latter involved ozone-sensitive (NC-S) and ozone-resistant (NC-R) biotypes of white clover (Trifolium repens L.) grown according to a common protocol and monitored for ozone injury and biomass differences in 17 European countries, from 1996 to 2006. Effects were separated into visible injury or growth/yield reduction. Of the 644 records of visible injury, 39% were for crops (27 species), 38.1% were for (semi-) natural vegetation (95 species) and 22.9% were for shrubs (49 species). Owing to inconsistencies in reporting effort from year to year it was not possible to determine geographical or temporal trends in the data. Nevertheless, this study has shown effects in ambient air in 18 European countries from Sweden in the north to Greece in the south. These effects data were superimposed on AOT40 (accumulated ozone concentrations over 40 ppb) and POD3gen (modelled accumulated stomatal flux over a threshold of 3 nmol m−2 s−1) maps generated by the EMEP Eulerian model (50 km × 50 km grid) that were parameterized for a generic crop based on wheat and NC-S/NC-R white clover. Many effects were found in areas where the AOT40 (crops) was below the critical level of 3 ppm h. In contrast, the majority of effects were detected in grid squares where POD3gen (crops) were in the mid-high range (>12 mmol m−2). Overall, maps based on POD3gen provided better fit to the effects data than those based on AOT40, with the POD3gen model for clover fitting the clover effects data better than that for a generic crop.
|
|
