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AbstractAlthough our observing capabilities of solar‐induced chlorophyll fluorescence (SIF) have been growing rapidly, the quality and consistency of SIF datasets are still in an active stage of research and development. As a result, there are considerable inconsistencies among diverse SIF datasets at all scales and the widespread applications of them have led to contradictory findings. The present review is the second of the two companion reviews, and data oriented. It aims to (1) synthesize the variety, scale, and uncertainty of existing SIF datasets, (2) synthesize the diverse applications in the sector of ecology, agriculture, hydrology, climate, and socioeconomics, and (3) clarify how such data inconsistency superimposed with the theoretical complexities laid out in (Sun et al., 2023) may impact process interpretation of various applications and contribute to inconsistent findings. We emphasize that accurate interpretation of the functional relationships between SIF and other ecological indicators is contingent upon complete understanding of SIF data quality and uncertainty. Biases and uncertainties in SIF observations can significantly confound interpretation of their relationships and how such relationships respond to environmental variations. Built upon our syntheses, we summarize existing gaps and uncertainties in current SIF observations. Further, we offer our perspectives on innovations needed to help improve informing ecosystem structure, function, and service under climate change, including enhancing in‐situ SIF observing capability especially in “data desert” regions, improving cross‐instrument data standardization and network coordination, and advancing applications by fully harnessing theory and data.

Miscanthus (ANDERSSON) is considered a promising perennial industrial crop for providing biomass in a growing bioeconomy. One approach to increasing the biodiversity-enhancing ecosystem services of Miscanthus is the co-cultivation of flower-rich native wild plant species (WPS), for example, the perennial WPS common tansy (Tanacetum vulgare L.) and mugwort (Artemisia vulgaris L.), as well as the biennial WPS wild teasel (Dipsacus fullonum L.) and yellow melilot (Melilotus officinalis L.). This study tested whether these selected WPS would be as suitable for combustion as Miscanthus, in this case the sterile hybrid Miscanthus x giganteus Greef et Deuter, allowing for a mixing of the biomasses. By doing so, no additional value chain (e.g. biogas production) would be necessary to economically exploit the diversification of the agricultural system for bioenergy production. Feedstock samples of Miscanthus and the four above-mentioned WPS from a field trial in southwest Germany were used to investigate the combustion characteristics as well as the higher heating value (HHV). It was found that all WPS exhibited better combustion properties than Miscanthus with respect to ash melting behavior at similar HHVs of 16.3–17.5 MJ kg−1. From an admixture of >30% WPS to the Miscanthus biomass, a significant increase in the ash melting temperature by 20% from 1000 to 1200 °C was shown. Thus, the mixture of WPS and Miscanthus could potentially improve the combustion quality, leading to reduced costs in the incineration plant operation process. However, the reduced costs of incineration should be greater than the loss in productivity due to the lower biomass yields from the WPS. This is highly dependent on the particular site conditions and the establishment success of the WPS and needs to be investigated in long-term studies.

Alternative Food Networks (AFNs) are challenging the traditional food system by leveraging concepts such as self-organisation and self-management aiming to shorten the food supply chain and give cu...

While clonal integration can improve the performance of rhizomatous plants, it remains unclear whether their clonal integration strategy changes under contrasting clipping and saline-alkali homogeneous and heterogeneous environments. Leymus chinensis is a clonal grass native to the Songnen grassland where heavy grazing and patchy saline-alkali stress are serious environmental and ecological problems. We hypothesized that L. chinensis overcomes these stresses through clonal integration, in particular the transfer of nitrogen and carbohydrates.A pot experiment was carried out with 15N isotope soil labeling method to study clonal integration strategy in the connected mother and daughter ramets of L. chinensis. The connected ramet pairs were grown in homogeneous (both connected ramets were treated) and heterogeneous (only daughter ramets were treated) environments with four treatments: control, clipping (60% aboveground biomass removal), saline-alkali (3.45 g of NaCl, NaHCO3, and Na2CO3 per pot), and clipping × saline-alkali.A significant amount (22.5%) of 15N was transferred from mother to daughter ramets under non-stressed conditions. When homogeneously stressing both mother and daughter ramets, N transfer was significantly reduced to 8.5--14.6%, independent of the nature of the stress. When only daughters were stressed (heterogeneous stress), saline-alkali stress led to a division of labor where daughters had enhanced photosynthesis, and mother ramets had increased 15N uptake and growth. Clipping only daughters reduced biomass and 15N uptake of both daughter and mother ramets.Our results demonstrated that clonal integration also occurs in homogeneous favorable environments but is reduced under homogeneous stress. In heterogeneous environments, clonal integration is used to translocate resource after clipping and a division of labor is established to overcome saline-alkali stress. Clonal integration continued even when daughters were severely stressed by the combined treatments. Our findings suggest that these mechanisms are key to the success of L. chinensis in the Songnen grassland.

AbstractMountain treelines are thought to be sensitive to climate change. However, how climate impacts mountain treelines is not yet fully understood as treelines may also be affected by other human activities. Here, we focus on “closed‐loop” mountain treelines (CLMT) that completely encircle a mountain and are less likely to have been influenced by human land‐use change. We detect a total length of ~916,425 km of CLMT across 243 mountain ranges globally and reveal a bimodal latitudinal distribution of treeline elevations with higher treeline elevations occurring at greater distances from the coast. Spatially, we find that temperature is the main climatic driver of treeline elevation in boreal and tropical regions, whereas precipitation drives CLMT position in temperate zones. Temporally, we show that 70% of CLMT have moved upward, with a mean shift rate of 1.2 m/year over the first decade of the 21st century. CLMT are shifting fastest in the tropics (mean of 3.1 m/year), but with greater variability. Our work provides a new mountain treeline database that isolates climate impacts from other anthropogenic pressures, and has important implications for biodiversity, natural resources, and ecosystem adaptation in a changing climate.

The combustion quality of three perennial wild plant species Tanacetum vulgare L., Centaurea nigra L. and Artemisia vulgaris L. was investigated in comparison to the energy yield obtained from anaerobic digestions of these biomasses. Combustion resulted in 1.5-2.8 times higher energy yield compared to anaerobic digestion. All wild plants showed a similar higher heating value to Miscanthus × giganteus Greef et Deuter and Panicum virgatum L. (16.0-17.0 MJ kg-1). The ash-melting behavior of all wild plants was like Sida hermaphrodita L. Rusby, since the ash did not sinter at 1200 °C. However, Artemisia vulgaris L. had highest ash content (5.2-5.7% of dry matter) with a low ash melting behavior (1000 °C) attributed to a high potassium content and calculated phase composition. Therefore, careful consideration should be given to select the wild plants to meet the requirements for their use as solid biofuels in residential and commercial applications.

PurposeThe purpose of this paper is to explore the potential impact of food sharing platform business models and to identify the limits and barriers in measuring the impact. Using the “theory of change” (ToC) approach, this paper develops a theoretical framework that captures the activities, outputs and outcomes of food sharing platforms and links them to indicators.Design/methodology/approachThe study employs a two-step methodology, which includes a website content analysis followed by two focus groups. The purpose of the website content analysis was to list a set of activities that are performed by food sharing platforms. The focus groups allow to design the ToC and to discuss limits and barriers in measuring the impact of food sharing platforms.FindingsThe study provides an overview of the main areas of impact of food sharing platforms (environmental, social, economic and political) and identifies the related outcomes. Furthermore, the paper highlights the need for the platform to manage the multifaceted tensions of food waste recovery vs prevention and the benefits of food recovery to helping hungry people vs the actual need to eradicate poverty by addressing social injustices and inequalities.Research limitations/implicationsThe selected sample involved in the focus group comprised a wide but not comprehensive set of stakeholders. Indeed, the obtained information cannot be generalized. In addition, the ToC approach requires a certain discretion of the facilitator and introduces the potential for partiality in conducting the analysis.Practical implicationsThe framework helps to unbundle the complex challenge of measuring the impact of food sharing platforms and it provides managers, practitioners and policy makers with a practical tool to direct their activities toward a better impact.Originality/valueFrom a theoretical perspective the study advances the literature on (food) sharing platforms and contributes to research on the sustainability in the food sector. It indicates the impacts a novel actor relying on digital technology can have in the food sector and points out the tensions between food recovery and prevention and the impact on poverty. The proposed framework could be a useful tool to support practitioners in understanding the trade-offs among the outcomes they aim to attain, and to identify the proper strategies to manage them.