Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems

Impatti, adattamento e vulnerabilita Le cause e le responsabilita dei cambiamenti climatici sono state trattate sul numero di ottobre della rivista Cda. Approfondiamo l’argomento presentando il documento: “Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita” votato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamenti Climatici (Intergovernmental Panel on Climate Change). Si tratta del secondo di tre documenti che compongono il quarto rapporto sui cambiamenti climatici.

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Climate Change 2007: Impacts, Adaptation and Vulnerability.

Plant traits – the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs – determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from species richness to ecosystem functional diversity. Trait data thus represent the raw material for a wide range of research from evolutionary biology, community and functional ecology to biogeography. Here we present the global database initiative named TRY, which has united a wide range of the plant trait research community worldwide and gained an unprecedented buy-in of trait data: so far 93 trait databases have been contributed. The data repository currently contains almost three million trait entries for 69 000 out of the world's 300 000 plant species, with a focus on 52 groups of traits characterizing the vegetative and regeneration stages of the plant life cycle, including growth, dispersal, establishment and persistence. A first data analysis shows that most plant traits are approximately log-normally distributed, with widely differing ranges of variation across traits. Most trait variation is between species (interspecific), but significant intraspecific variation is also documented, up to 40% of the overall variation. Plant functional types (PFTs), as commonly used in vegetation models, capture a substantial fraction of the observed variation – but for several traits most variation occurs within PFTs, up to 75% of the overall variation. In the context of vegetation models these traits would better be represented by state variables rather than fixed parameter values. The improved availability of plant trait data in the unified global database is expected to support a paradigm shift from species to trait-based ecology, offer new opportunities for synthetic plant trait research and enable a more realistic and empirically grounded representation of terrestrial vegetation in Earth system models.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1365-2486.2011.02451.x

TRY - a global database of plant traits

Data on bulk nitrogen deposition, plant foliar nitrogen and crop nitrogen uptake in China between ad 1980 and ad 2010 show that the average annual bulk deposition of nitrogen increased by approximately 8 kilograms of nitrogen per hectare during that period and that nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s. Atmospheric nitrogen emissions have increased substantially since the beginning of the industrial revolution, and the resulting deposition of nitrogen can have detrimental effects on human and ecosystem health. But little is known about the magnitude and environmental consequences of nitrogen deposition in today's fastest growing economy, China. This paper reports that average annual bulk deposition of nitrogen increased by 8 kg of nitrogen per hectare from the 1980s to the 2000s. Ammonium is the dominant form of nitrogen in bulk deposition, whereas the rate of increase is largest for nitrate deposition. Nitrogen deposition has also increased plant foliar nitrogen concentrations in semi-natural ecosystems and has elevated crop nitrogen uptake in long-term unfertilized croplands. China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen1,2. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity1,3,4,5. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s6, before the introduction of mitigation measures7,8. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3−), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

http://www.sainonline.org/pages/downloads/中英可持续集约化农业养分管理和水资源保护项目/Related%20publications/Liu%20XJ,Zhang%20FS-natureEnhanced%20nitrogen%20deposition%20over%20China.pdf

Enhanced nitrogen deposition over China

The authors found that the key elements of plant form and function, analysed at global scale, are largely concentrated into a two-dimensional plane indexed by the size of whole plants and organs on the one hand, and the construction costs for photosynthetic leaf area, on the other.

The global spectrum of plant form and function

Thlaspi caerulescens is commonly known as a zinc (Zn) and cadmium (Cd) hyperaccumulator, which can be used to clean up the Zn- and/or Cd-contaminated soil. However, it is unclear whether high soil Zn concentrations will stimulate undue accumulations of other elements to such an extent as to cause the nutrient unbalance in the soil. To address this question, the inductively coupled plasma-atomic emission spectrometry (ICP-AES) was employed to investigate the effect of Zn on the stoichiometry of Zn, Cd, K, P, Mg, Ca, Fe, Mn and Cu in T. caerulescens (Ganges ecotype) exposed to low, middle and high Zn concentrations (5, 50 and 500 micromol x L(-1), respectively) in a hydroponic experiment. The results showed that there were no significant variations in contents of Cd, K, P, Mg, Ca, Fe, Mn and Cu in the shoot of T. caerulescens, however, the Zn content in the shoot and root with 500 mciromol x L(-1) Zn treatment increased as much as 13 times higher than that with low Zn exposure, indicating that the plant is capable of Zn hyperaccumulating. The authors' study suggests that it is improbable to induce soil nutrient unbalance when T. caerulescensis (Ganges) is used for phytoremediation of Zn-contaminated soil, in that over-uptake of nutrient elements from the soil other than Zn was not observed, at least for the elements K, P, Mg, Ca, Fe, Mn and Cu.

[Stoichiometry of multi-elements in the zinc-cadmium hyperaccumulator Thlaspi caerulescens grown hydroponically under different zinc concentrations determined by ICP-AES].

Inactivation of a pathogenic NDM-1-positive Escherichia coli strain and the resistance gene blaNDM-1 by TiO2/UVA photocatalysis.

Review on the mechanism models of allometric scaling laws: 3/4 vs. 2/3 power

Nitrogen (N) addition has profound impacts on litter-mediated nutrient cycling. Numerous studies have reported different effects of N addition on litter decomposition, exhibiting positive, negative, or neutral effects. Previous meta-analysis of litter decomposition under N addition was mainly based on a small number of samples to allow comparisons among ecosystem types. This study presents the results of a meta-analysis incorporating data from 53 published studies (including 617 observations) across forests, grasslands, wetlands, and croplands in China, to investigate how environmental and experimental factors impact the effects of N addition on litter decomposition. Averaged across all of the studies, N addition significantly slows litter decomposition by 7.02%. Considering ecosystem types, N addition significantly accelerates litter decomposition by 3.70% and 11.22% in grasslands and wetlands, respectively, clearly inhibits litter decomposition by 14.53% in forests, and has no significant effects on litter decomposition in croplands. Regarding the accelerated litter decomposition rate in grasslands due to N addition, litter decomposition rate increases slightly with increasing rates of N addition. However, N addition slows litter decomposition in forests, but litter decomposition is at a significantly increasing rate with increasing amounts of N addition. The responses of litter decomposition to N addition are also influenced by the forms of N addition, experiential duration of N addition, humidity index, litter quality, and soil pH. In summary, N addition alters litter decomposition rate, but the direction and magnitude of the response are affected by the forms of N addition, the rate of N addition, ambient N deposition, experimental duration, and climate factors. Our study highlights the contrasting effects of N addition on litter decomposition in forests and grasslands. This finding could be used in biogeochemical models to better evaluate ecosystem carbon cycling under increasing N deposition due to the differential responses of litter decomposition to N addition rates and ecosystem types.

Wenxuan Han

Papers

[Stoichiometry of multi-elements in the zinc-cadmium hyperaccumulator Thlaspi caerulescens grown hydroponically under different zinc concentrations determined by ICP-AES].

Inactivation of a pathogenic NDM-1-positive Escherichia coli strain and the resistance gene blaNDM-1 by TiO2/UVA photocatalysis.

Review on the mechanism models of allometric scaling laws: 3/4 vs. 2/3 power

Contrasting effects of nitrogen addition on litter decomposition in forests and grasslands in China

Decoupling of N and P aggravated upward along food chains in an urban river ecosystem.