Biodiversity Assessment of Value Chains: State of the Art and Emerging Challenges

Toward Better Biodiversity Impact Assessment of Agricultural Land Management through Life Cycle Assessment: A Systematic Review

Agricultural intensification has driven global biodiversity loss through land management change. However, there is no consensus on assessing the biodiversity impacts of changes in land management practices and intensity levels using life cycle assessment (LCA). This study reviews 7 expert scoring-based (ESB) and 19 biodiversity indicator-based (BIB) LCA methods used to assess biodiversity impacts, aiming to evaluate their quality and identify research needs for incorporating land management change in LCA. Overall, BIB methods outperformed ESB methods across general criteria, especially in robustness (95% higher). BIB methods assess biodiversity impacts based on land management intensity levels, whereas ESB methods emphasize specific land management practices. Neither approach fully captures biodiversity impacts across supply chains. For future studies, it is advisable to (1) model the direct (on-farm) impacts of land management change at the midpoint level; (2) establish cause-effect relationships between key land management practices and biodiversity indicators, while distinguishing between direct (on-site) and indirect (off-site) biodiversity impacts resulting from land management change; (3) characterize land-use intensity levels with specific land management practices and include the positive impacts from agroecological practices. This Review examines LCA methods for biodiversity concerning land management practices and discusses improvements to better account for the biodiversity impacts of agricultural land management.

Environmental trade-offs of meeting nutritional requirements with a lower share of animal protein for adult subpopulations

Decreasing the share of protein contributed by animal-based foods is recommended to move towards more sustainable and healthier diets. This study aimed to assess the potential environmental impacts of diets with a lower share of animal protein. The diets were modeled to include the minimum share of animal protein in total protein that met nutrient requirements and did not increase costs. The new diets also minimized the difference in the quantity of food from those of observed (OBS) diets. They were modeled for five adult subpopulations (defined by sex and age) using mathematical optimization. The model was created by combining the INCA2 database (to model OBS diets in the French population) and a database of 207 food items to adjust nutritional and price parameters. All modeled diets satisfied nutritional and cost constraints. A low-animal-protein (LAP) diet was identified for each subpopulation by progressively decreasing the share of animal protein by steps of 5% until the recommended quantity of protein and/or consumption constraints were no longer satisfied. Potential environmental impacts of the LAP diets in eight impact categories were calculated using life cycle assessment and life cycle inventories from Agribalyse® 3.0. A LAP diet for the entire population was calculated as a weighted mean of the subpopulations' LAP diets. The share of animal protein decreased from 70% in the OBS diet to 50% in the LAP diet. Compared to the OBS diet, the LAP diet decreased five environmental impacts: climate change (greenhouse gas emissions), acidification (emissions of acidifying compounds) and land occupation (all by more than 30%), cumulative energy demand (by 23%) and marine eutrophication (by 13%). Conversely, it increased three environmental impacts: freshwater eutrophication and water use (both by ca. 40%) and biodiversity damage potential (potential loss of species associated with land use) (by 66%). These results suggest that decreasing the share of animal protein to 50% is compatible with nutritional requirements, affordability and consumption constraints, but would have mixed effects on the environment.

Food environmental footprint: Evolution of the countryside species-area relationship (SAR) with new methodologies

The species-area relationship (SAR) is one of the oldest in ecology, linking the increase in species richness in sampling area. Later, new parameters were incorporated into its equation, such as taxon-specific responses, habitats use by species and species adapted to human-modified habitats, originating the Countryside SAR, a version intended to integrate the life cycle assessment (LCA) methodology, which is still inefficiencies when used to evaluate food production systems. Therefore, we present the first attempt to incorporate into Countryside SAR the minimum land demand parameter for food production, the food environmental footprint - EFP, and improve the use of the method within the agricultural sciences scope. To prepare the EFP, we used land cover data for two types of food systems: agriculture (annual crops), composed of nine types of food; and, livestock (pasture), consisting of meat production. They were later tested in inventories for the Western European broadleaf forest ecoregion (ecocode: PA0445). The most important result observed was that the models responded to variations in production values, resulting in higher impact and a more conservative result when EFP is adopted. But as historically integrating a productivity parameter, or performance of production systems, has been left out of the development of SAR, only the first step has been taken. Therefore, incorporating minimum land demand for food production into the Countryside SAR appears to be a new stage in its development, allowing to generate results that consider the "efficiency" of food production, assuming a more agronomic profile. However, this is still the first attempt to include the EFP in the Countryside SAR, and we believe that our models should still be subject to further evaluation.

Deconstruction and analysis of global biodiversity loss transfer network based on the social network analysis method

Biodiversity is crucial for maintaining ecosystem stability and achieving sustainable development. However, global biodiversity loss is a common challenge faced by most countries. Therefore, based on the data from the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and the Eora database, we used the multi-regional input-output (MRIO) model to calculate biodiversity loss in 188 countries. We constructed a global biodiversity loss transfer network from the binary and weighted perspectives and deconstructed the evolution characteristics and the factors influencing the network from the "relationship" perspective using social network analysis (SNA) and quadratic assignment procedure (QAP) method. The global biodiversity loss transfer network had a typical network structure with dense connections, demonstrating spatial correlation characteristics. The countries with top in- and out-degree centrality rankings were developed and large-scale emerging economies and developing countries in Africa, respectively, implying that the former are responsible for "importing" large amounts of biodiversity and transferring biodiversity loss to the latter. The block model analysis indicated that the transfer network was divided into different functional blocks, with biodiversity spillover effects. The QAP analysis revealed that the differences in geographical adjacency, per capita GDP, urbanization rate, environmental regulation, and agricultural land proportion explained 3.627% of the changes in the global biodiversity loss transfer network. Our results suggested that the relationships of biodiversity loss transfer among countries should be considered by policymakers to address biodiversity challenges. Therefore, governments should recognize the remote responsibility, reduce unsustainable consumption and production, develop sustainable trade, and make trade policies considering the transfer of biodiversity impacts.

Examining global biodiversity accounts: Implications of aggregating characterization factors from elementary flows in multi-regional input-output analysis

Extending multi-regional input-output (MRIO) models with spatially explicit life cycle impact assessment (LCIA) models allows practitioners to quantify biodiversity impacts at every step of global supply chains. Inconsistencies may be introduced, however, when high-resolution characterization factors (CFs) are aggregated so as to match the low spatial granularity of MRIO models. These aggregation errors are greater when CFs are aggregated via proxies, such as ecoregion land shares, instead of based on spatially explicit elementary stressor flows. Here, we describe our approach to tailoring application-specific CFs for use in MRIO studies. We apply a global agricultural production model, Spatial Production Allocation Model (MapSPAM), with the LCIA database, LC-IMPACT, to create crop-specific national CFs. We investigated i) if the differing aggregation approaches and the increased spatial explicitness of the constructed CFs deviate substantially from those in LC-IMPACT, and ii) what the resulting consequences for national production and consumption-based biodiversity footprints are when combining the tailor-made CFs with the EXIOBASE MRIO model. For the year 2020, we observe an increase in global production-based biodiversity impacts of 23.5% for land use when employing crop-specific CFs.

Carbon footprint distributions of lithium-ion batteries and their materials

Lithium-ion batteries are pivotal in climate change mitigation. While their own carbon footprint raises concerns, existing studies are scattered, hard to compare and largely overlook the relevance of battery materials. Here, we go beyond traditional carbon footprint analysis and develop a cost-based approach, estimating emission curves for battery materials lithium, nickel and cobalt, based on mining cost data. Combining the emission curves with regionalised battery production announcements, we present carbon footprint distributions (5th, 50th, and 95th percentiles) for lithium-ion batteries with nickel-manganese-cobalt (NMC811, 8-1-1 ratio; 59, 74 and 115 kgCO2 kWh-1) and lithium-iron-phosphate (LFP; 54, 62, 69 kgCO2 kWh-1) cathodes. Our findings reveal the dominating impact of material sourcing over production location, with nickel and lithium identified as major contributors to the carbon footprint and its variance. This research moves the field forward by offering a nuanced understanding of battery carbon footprints, aiding in the design of decarbonisation policies and strategies.

Environmental assessment of diets: overview and guidance on indicator choice

Comprehensive but interpretable assessment of the environmental performance of diets involves choosing a set of appropriate indicators. Current knowledge and data gaps on the origin of dietary foodstuffs restrict use of indicators relying on site-specific information. This Personal View summarises commonly used indicators for assessing the environmental performance of diets, briefly outlines their benefits and drawbacks, and provides recommendations on indicator choices for actors across multiple fields involved in activities that include the environmental assessment of diets. We then provide recommendations on indicator choices for actors across multiple fields involved in activities that use environmental assessments, such as health and nutrition experts, policy makers, decision makers, and private-sector and public-sector sustainability officers. We recommend that environmental assessment of diets should include indicators for at least the five following areas: climate change, biosphere integrity, blue water consumption, novel entities, and impacts on natural resources (especially wild fish stocks), to capture important environmental trade-offs. If more indicators can be handled in the assessment, indicators to capture impacts related to land use quantity and quality and green water consumption should be used. For ambitious assessments, indicators related to biogeochemical flows, stratospheric ozone depletion, and energy use can be added.

Recent Developments and Challenges in Projecting the Impact of Crop Productivity Growth on Biodiversity Considering Market-Mediated Effects

The effect of an increase in crop productivity (output per unit of inputs) on biodiversity is hitherto poorly understood. This is because increased productivity of a crop in particular regions leads to increased profit that can encourage expansion of its cultivated area causing land use change and ultimately biodiversity loss, a phenomenon also known as "Jevons paradox" or the "rebound effect". Modeling such consequences in an interconnected and globalized world considering such rebound effects is challenging. Here, we discuss the use of computable general equilibrium (CGE) and other economic models in combination with ecological models to project consequences of crop productivity improvements for biodiversity globally. While these economic models have the advantage of taking into account market-mediated responses, resource constraints, endogenous price responses, and dynamic bilateral patterns of trade, there remain a number of important research and data gaps in these models which must be addressed to improve their performance in assessment of the link between local crop productivity changes and global biodiversity. To this end, we call for breaking the silos and building interdisciplinary networks across the globe to facilitate data sharing and knowledge exchange in order to improve global-to-local-to-global analysis of land, biodiversity, and ecosystem sustainability.

What Is the Impact of Accidentally Transporting Terrestrial Alien Species? A New Life Cycle Impact Assessment Model

Alien species form one of the main threats to global biodiversity. Although Life Cycle Assessment attempts to holistically assess environmental impacts of products and services across value chains, ecological impacts of the introduction of alien species are so far not assessed in Life Cycle Impact Assessment. Here, we developed country-to-country-specific characterization factors, expressed as the time-integrated potentially disappeared fraction (PDF; regional and global) of native terrestrial species due to alien species introductions per unit of goods transported [kg] between two countries. The characterization factors were generated by analyzing global data on first records of alien species, native species distributions, and their threat status, as well as bilateral trade partnerships from 1870-2019. The resulting characterization factors vary over several orders of magnitude, indicating that impact greatly varies per transportation route and trading partner. We showcase the applicability and relevance of the characterization factors for transporting 1 metric ton of freight to France from China, South Africa, and Madagascar. The results suggest that the introduction of alien species can be more damaging for terrestrial biodiversity as climate change impacts during the international transport of commodities.

Life Cycle Assessment of a large commercial kelp farm in Shandong, China

The environmental benefits of seaweed cultivation have gained a lot of attention, both in policy strategies and by private companies. Sustainability evaluations of seaweed farming have however focused on a very small part of global production of seaweed - on European cultivations at research and pilot-scales although Asia stands for 99 % of global production with China alone producing 60 %. In this study, we use Life Cycle Assessment (LCA) to evaluate the environmental performance of a 400-hectare Chinese kelp farm with a yearly harvest of 60,000 tons. Primary data from the farm was used to assess impacts up until harvest for the functional unit of 1 ton of fresh-weight kelp. Included in the LCA were impact on climate change, acidification terrestrial and marine eutrophication, and use of land water and energy. In addition, we calculated nutrient uptake. Further, we extracted inventory data of four published LCA studies of farmed kelp and recalculated environmental impacts, applying the same background data and method choices with the aim to compare the effects of scale and cultivation system. The results of the hotspot analysis showed that the plastic ropes and buoys dominated impacts on climate change, freshwater and marine eutrophication, and energy consumption. Consequently, the most effective improvement action was recycling after use. The yearly harvest of the Chinese farm was 1000-4000 times larger than previously evaluated farms compared. Results suggest that streamlined and mature production in the large-scale Chinese kelp farm led to lower electricity and fuel consumption compared to small-scale production, thus placing the Chinese farm with a climate impact of 57.5 kg CO2 eq. per ton fresh-weight kelp on the lower end when comparing the carbon footprint. There was a large variation in carbon footprints, which implies that the kelp cultivation sector has considerable room for optimization.

Climate and biodiversity impacts of low-density polyethylene production from CO2 and electricity in comparison to bio-based polyethylene

Plastics are essential materials for modern societies, but their production contributes to significant environmental issues. Power-to-X processes could produce plastics from captured CO₂ and hydrogen with renewable electricity, but these technologies may also face challenges from environmental perspective. This paper focuses on environmental sustainability assessment of CO₂-based low-density polyethylene (LDPE) compared to bio-based LDPE. Life cycle assessment has been applied to study climate impacts and land use related biodiversity impacts of different plastic production scenarios. According to the climate impact results, the carbon footprint of the produced plastic can be negative if the energy used is from wind, solar, or bioenergy and the carbon captured within the plastic is considered. In terms of biodiversity, land-use related biodiversity impacts seem to be lower from CO₂-based polyethylene compared to sugarcane-based polyethylene. Forest biomass use for heat production in CO₂-based polyethylene poses a risk to significantly increase biodiversity impacts. Taken together, these results suggest that CO₂-based LDPE produced with renewable electricity could reduce biodiversity impacts over 96 % while carbon footprint seems to be 6.5 % higher when compared to sugarcane-based polyethylene.

Can Forest Management Practices Counteract Species Loss Arising from Increasing European Demand for Forest Biomass under Climate Mitigation Scenarios?

Forests are home to many species and provide biomass for material and energy. Here, we modeled the potential global species extinction risk from future scenarios of climate mitigation and EU28 forest management. We considered the continuation of current practices, the adoption of closer-to-nature management (low-intensity practices), and set-asides (conversion to unharvested forestland) on portions of EU28 forestland under two climate mitigation pathways as well as the consequences for the wood trade. Expanding set-aside to more than 25% of EU28 currently managed forestland by 2100 increased the global extinction risk compared to the continuation of current practices. This outcome stems from a projected increase in EU forest biomass imports, partially from biodiversity-vulnerable regions to compensate for a decrease in domestic harvest. Conversely, closer-to-nature management on up to 37.5% of EU28 forestland lowered extinction risks. Increasing the internal production and partially sourcing imported biomass from low-intensity managed areas lowered the species extinction footprint even further. However, low-intensity practices could not entirely compensate for the increased extinction risk under a high climate mitigation scenario with greater demand for lignocellulosic crops and energywood. When developing climate mitigation strategies, it is crucial to assess forest biomass supply chains for the early detection of extinction risks in non-EU regions and for developing strategies to prevent increase of global impacts.

Complex ecological and socioeconomic impacts on medicinal plant diversity

Medicinal plant diversity (MPD) is an important component of plant diversity. Over-collection based on medicinal and economic value has the potential to damage the stability of the regional ecosystem. It is important to understand the current distribution of MPD and the factors influencing it. However, it is still unclear whether environmental and socioeconomic conditions have an impact on their distribution. We selected the Inner Mongolia as a representative study area which covers a wide area, accounting for 12.29% of China’s national land area and 0.79% of the world’s land area. At the same time, the region is a long-standing traditional medicinal area for Mongolians in China. Therefore, the region is significantly influenced by changes in environmental factors and socio-economic factors. We used 9-years field survey of the distribution of medicinal plants in Inner Mongolia for assessing the distribution of MPD as influenced by environmental and socioeconomic activities by combining spatial analyses, species distribution models, and generalized additive models. The results from the spatial analysis show that the western region of Inner Mongolia is the main cold spot area of the MPD, and the central-eastern and northeastern regions of Inner Mongolia are the main hot spot areas of the MPD. At the same time, the distribution of cold spots and hot spots of MPD is more obvious at large spatial scales, and with the refinement of spatial scales, the cold spots in scattered areas are gradually revealed, which is indicative for the conservation and development of MPD at different spatial scales. Under the future climate change of shared socioeconomic pathways (SSP), areas with high habitat suitability for medicinal plants remain mainly dominated by the Yellow River, Yin Mountains, and Greater Khingan Range. Notably, the SSP245 development pathway remains the most significant concern in either long- or short-term development. The nonlinear relationship between the driving factors of MPD at different spatial scales shows that temperature, precipitation and socioeconomic development do have complex effects on MPD. The presence of a certain temperature, altitude, and precipitation range has an optimal facilitation effect on MPD, rather than a single facilitation effect. This complex nonlinear correlation provides a reference for further studies on plant diversity and sustainable development and management. In this study, the spatial distribution of medicinal plant resources and the extent to which they are driven by ecological and socioeconomic factors were analyzed through a macroscopic approach. This provides a reference for larger-scale studies on the environmental and socioeconomic influences on the distribution of plant resources.

Contribution of High Nature Value farming systems to sustainable livestock production: A case from Finland

Sustainability of livestock production is a highly contested issue in agricultural sustainability discourse. This study aimed to assess the environmental impact of farms using semi-natural grasslands in Finland, or so-called High Nature Value (HNV) farms. We estimated the environmental impact of 11 such farms, including greenhouse gas emissions (GHG), nitrogen (N) balance, land occupation, and carbon storage. We also accounted for unique biodiversity, defined in this study as communities that are dependent on semi-natural grasslands. We compared these to the alternative states of the farms, specifically a hypothetical farm with the same production output but without access to semi-natural grasslands. GHG emissions at the farm level (tCO_2eq/ha) in HNV farms were 64% lower than on the alternative farms; GHG emissions at the product level (tCO_2eq/t LW) and N balance (N kg/ha) were 31% and 235% lower, respectively. The carbon stocks were 163% higher at farm level. Biodiversity values, indicated by the share of semi-natural grassland in management, ranged from 23% to 83% on HNV farms. Six out of eleven farms would need to increase their arable land occupation by an average of 39% of arable land to fulfil their needs for animal feed if they did not utilize semi-natural grassland. This study contributes to growing evidence that HNV farming systems can support sustainable production by minimising arable land occupation, reducing nutrient loses, and increasing carbon storage while maintaining unique biodiversity.

Accounting for land use changes beyond the farm-level in sustainability assessments: The impact of cocoa production

Impact assessments are used to raise evidence and guide the implementation of sustainability strategies in commodity value chains. Due to methodological and data difficulties, most assessments of agricultural commodities capture the impacts occurring at the farm-level but often dismiss or oversimplify the impacts caused by land use dynamics at larger geographic scale. In this study we analyzed the impacts of two cocoa production systems, full-sun and agroforestry, at the farm-level and beyond the farm-level. We used life cycle assessment to calculate the impacts at the farm-level and a combination of land use modelling with spatial analysis to calculate the impacts beyond the farm-level. We applied this to three different future cocoa production scenarios. The impacts at the farm-level showed that, due to lower yields, cocoa agroforestry performs worse than cocoa full-sun for most impact indicators. However, the impacts beyond the farm-level showed that promoting cocoa agroforestry in the landscape can bring the largest gains in carbon and biodiversity. A scenario analysis of the impacts at the landscape-level showed large nuances depending on the cocoa farming system adopted, market dynamics, and nature conservation policies. The analysis indicated that increasing cocoa demand does not necessarily result in negative impacts for carbon stocks and biodiversity, if sustainable land management and sustainable intensification are adopted. Landscape-level impacts can be larger than farm-level impacts or show completely opposite direction, which highlights the need to complement farm-level assessments with assessments accounting for land use dynamics beyond the farm-level.

Environmental and biodiversity effects of different beef production systems

Agricultural livestock production ranks among the most environmental impactful industry sectors at the global level, and within the livestock sector, beef production accounts for a large proportion of environmental damage. Beef production in Alpine mountain regions, such as in South Tyrol (Italy), is a small, but increasing agricultural sector. Thus, the aim of this study was to examine the environmental impact of different organic and conventional beef production systems in South Tyrol and to compare their environmental impact and effect on biodiversity under Alpine production conditions. Live cycle assessment (LCA) approach was used and 1 kg of live weight (LW) was chosen as functional unit (FU). Global warming potential (GWP, kg CO₂-eq), acidification potential (AP, g SO₂-eq), eutrophication potential (EP, g PO₄-eq), non-renewable energy use (NRE, MJ-eq), land occupation (LO, m² organic land/year) and biodiversity damage potential (BDP) expressed in potential disappeared fraction (PDF) were investigated. The study involved 18 beef cattle farms in the South Tyrolean region: Conventional calf-fattening farms (CCF = 6), organic suckler cow farms (SCF = 6), and conventional heifer/ox fattening farms (HOF = 6). The CCF system showed a higher environmental impact compared to SCF and HOF systems for all impact categories (P < 0.05). Between the organic and the conventional system (SCF and HOF), no significant differences (P > 0.05) were found for most of the considered impact categories (means ± SEM per FU): GWP: 19.8 vs 17.1 ± 4.2 kg CO_2-eq, AP: 11.4 vs 9.3 ± 4.7 g SO₂-eq, EP: 4.1 vs 2.8 ± 1.2, NRE: 21.9 vs 13.8 ± 7 MJ-eq, SCF and HOF respectively. Only for LO (70.8 vs 44.1 ± 17.7 m² organic/y, P < 0.01, SCF and HOF respectively) and the effect on BDP (-1.93 vs -0.85 ± 0.35, PDF, P < 0.01, SCF and HOF respectively) differences between organic and conventional production methods could be revealed. The study showed that beef cattle husbandry in the Alpine area has a satisfactory environmental performance. In particular, the systems studied showed a positive impact in terms of biodiversity.