Strong Trade-off Research Articles

Integrated analysis of opportunities and trade-offs for mixed crop-livestock farm types in Amhara, Ethiopia

CONTEXTIn Ethiopia, many agricultural interventions have been introduced for mixed farm types in different biophysical and socioeconomic conditions. The contribution of such interventions to multi-objectives at farm level and beyond remains unclear. OBJECTIVETo derive insights into interaction of multi-objectives on economic profit-, nutrition security-, and environmental performance that are relevant for improvement of farm household living income in Amhara, Ethiopia. METHODSFarmDESIGN model evaluated performance of four stylized medium- and small-scale farm types in a low (Lay Gayint)- and high (South Achefer)- potential district: LG-M, LG-S, SA-M and SA-S. Pareto-based multi-objective optimization was performed to maximize farm profit, livestock density, dietary energy and vitamin A yield, and minimize GHG and soil N losses. Further analysis resulted in 3–4 clusters per farm type with varied farm configurations. RESULTS AND CONCLUSIONSHigher dietary energy- and vitamin A- yield that meets household and Ethiopian society requirements increased synergistically with profit in three of the four farm type clusters, while LG-S clusters could only increase vitamin A yield substantially with profit. Only LG-M clusters intensified livestock by addition of 4–8 crossbred cows and 1–10 chickens, supported by imported feed and off-farm grazing but face strong environmental trade-offs of increased GHG and soil N losses. Chicken production (eggs and chicken meat) is an option to reduce environmental impact, increase profit and contribute to both human nutrition requirements. In LG-S, SA-M and SA-S farm type clusters, profit was generated mainly from sale of eucalyptus, maize, potato, carrot, finger millet, garlic, beetroot and banana, with eucalyptus accounting at least 35% of the crop profit. Livestock diversification in these clusters also contributed to farm revenue, but always to a smaller extent, due to relatively high management costs. A living income from farming activities was only achieved on SA-M3 as 3.96 USD/capita/day (+0.36 above the threshold). This cluster had a 2.90 ha land area, farm income almost equally generated from crop and livestock production, and successfully met all set objectives except maximizing livestock density. SIGNIFICANCEOur study infers the need to increase land area, expand poultry and rear crossbred cows, and cultivate high value crops to realize a living income solely from agricultural activities. For implementation, current land-use policies should support farm area expansion. The suggested agricultural options, which already align with current Ethiopian development plans, must utilize sustainable measures that will not lead to short- or long-term challenges as higher GHG and soil nutrient mining.

Pitfalls in global grassland restoration challenge restoration programs and the science-policy dialogue

Restoring degraded ecosystems is crucial for human wellbeing and biodiversity conservation. Nowadays, ecological restoration goes far beyond recovering a degraded ecosystem according to a historic reference. Instead, more specific restoration goals are set, following global environmental strategies that are individually highly important, but often conflicting. Furthermore, various pitfalls exist regarding the evaluation of ecosystem degradation and, directly related to this, the question what is the most desirable ecological state of an ecosystem. Ignoring such issues can lead to a failure of restoration projects and do more ecological (and social) harm than good. A crucial aspect in tackling conflicting goals and circumnavigating restoration pitfalls is the considerate choice of the indicators to assess ecosystem degradation and restoration capacity.In this Perspective, grasslands and rangelands are used exemplarily for ecosystems with globally high restoration demand. I discuss potential restoration pitfalls related to enhancing carbon sequestration, soil fertility, and ecosystem service multifunctionality. For all three goals, strong trade-offs and unwanted side effects exist. For example, while increasing carbon storage and restoring soil fertility are widely acknowledged environmental goals, both can compromise other restoration targets such as grassland biodiversity and further ecosystem services, depending on the specific context. Thus, there are no universally applicable indicators for ecosystem degradation and restoration. Instead, indicator systems have to account not only for strong trade-offs among restoration goals but also for a number of environmental and socio-ecological misconceptions, such as presented for the case of grassland ecosystems.I argue that one-sided goal setting and an imprudent choice of indicators can misguide the science-policy dialogue and related restoration efforts. To avoid this, restoration programs must integrate holistic assessments of their objectives across spatial scales and with all stakeholders concerned. The associated ecological indicator system for restoration success and program performance must therefore also be based on multidisciplinary and participatory approaches. Restoration and degradation indicators have to further ensure the target ecosystem is correctly and comprehensively identified, and the manifold conflicting land management objectives associated with heterogeneous human societies are taken into account. Researchers can assist this process by by-default considering the socio-ecological context of a restoration target and by identifying trade-offs arising from potential solutions, before these are suggested to the public. Only when all these aspects are considered, restoration projects at the local to global scale will result in long-term sustainable outcomes.

Biodiversity conservation, ecosystem services and organic viticulture: A glass half-full

Organic farming is a promising but still debated option to ensure sustainable agriculture. However, whether organic farming fosters synergies or mitigates tradeoffs between biodiversity, ecosystem services and crop production has rarely been quantified. Here, we investigate relationships between multitrophic diversity (14 taxa above and belowground), yield, natural pest control and soil quality (14 proxies of ecosystem services) in organic and conventional vineyards along a landscape gradient. Organic farming enhanced biodiversity and pest control, but decreased wine production. Compared to conventional systems, multitrophic diversity was 15 % higher, and pest control services were 9 % higher in organic systems, while wine production was 11 % lower. Regardless of management type, we found a strong tradeoff between wine production and pest control, but not between wine production and biodiversity. The landscape context was not a strong moderator of organic farming effects across taxa groups and ecosystem services, but affected specific taxa and ecosystem services, especially natural pest control. Our study reveals that wine production and biodiversity conservation do not necessarily exclude each other, which implies the existence of a safe operating space where biodiversity and wine production can be combined. We conclude that organic farming can contribute to improve the sustainability of viticulture, but needs to be complemented by management options at the local and landscape scales in order to fully balance biodiversity conservation with the simultaneous provision of multiple ecosystem services.

Chromatographic Separation of Rare Earth Elements as MGDA Complexes on Anion Exchange Resins

Chromatographic separation of rare earth elements (REE) as anionic complexes with chelating aminopolycarboxylate ligand methylglycine N,N-diacetate (MGDA) was studied experimentally. A synthetic mixture of La, Nd, and Eu were used to model a REE mixture obtained from processed secondary sources such as phosphogypsum (PG). In the REE extraction from PG, the REEs can be recovered with MGDA to obtain the REE–MGDA mixture. Three strong base anion exchange resins (Dowex 1X8, IRA-402, and IRA-410) were used as the separation materials. Successful separation of the REEs by elution with dilute HNO3 and HCl was attributed to differences in the stabilities of the REE–MGDA complexes. The pKa values of the complexes were determined by titration to be 3.81, 3.25, and 2.96 for La, Nd, and Eu, respectively. Fractionation of the ternary La-Nd-Eu mixture (with a 1:1:1 mole ratio) were studied. La was recovered at approximately 80% purity and 80% yield, but strong trade-offs between the yield and the purity of Nd and Eu must be made. Chromatographic separation was found to be an efficient process option, considering its simplicity and the recovery of several product fractions. The initial process design offers a promising starting point for investigating more advanced process configurations for the efficient recovery of pure REE from phosphogypsum.

Response and Multi-Scenario Prediction of Carbon Storage and Habitat Quality to Land Use in Liaoning Province, China

Liaoning Province, as an old industrial urban agglomeration since the founding of China, is an important link between the Bohai Economic Zone and the Northeast Economic Zone, and it has made great contributions to the economic development of China. The transformation of China’s economy and heavy industrial development have posed great challenges to the long-lasting growth of Liaoning Province. In this study, the driving force of land expansion was detected using the patch-generating land use simulation (PLUS) model in Liaoning Province, and the land situation in 2030 was predicted under natural development, ecological protection, and economic development scenarios. We then further coupled the PLUS model with the integrated valuation of ecosystem services and trade-offs (InVEST) model to explore the spatial autocorrelation and synergistic relationship between carbon storage and habitat quality. The results indicated the following: (1) The total accuracy of the simulation in 2020 using the PLUS model reached 94.16%, and the Kappa coefficient reached 0.9089; therefore, the simulation result was highly reliable. (2) The overall spatial pattern of both carbon storage and habitat quality decreased from the northwest and southeast to the middle, and habitat quality had an impact on carbon storage to a certain extent, with a positive spatial correlation. (3) The ecological protection (EP) scenario was the only development prospect with increasing total carbon storage, which could increase carbon sequestration by approximately 7.83 × 106 Mg/C, and development prospects with optimal habitat quality. (4) Weak trade-off and weak synergy dominated in the 2030 natural development (ND) scenario; most regions showed weak synergy in the ecological protection scenario, spatial heterogeneity became more pronounced in the economic development (ED) scenario, and a strong trade-off and strong synergy emerged in individual regions. The results of the study have a positive feedback effect on establishing an ecological security barrier in Liaoning Province and furthering long-lasting low-carbon urban development.

Planetary boundaries assessment of deep decarbonisation options for building heating in the European Union

Building heating is one of the sectors for which multiple decarbonisation options exist and current geopolitical tensions provide urgency to design adequate regional policies. Heat pumps and hydrogen boilers, alongside alternative district heating systems, are the most promising alternatives. Although a host of city or country-level studies exist, it remains controversial what role hydrogen should play for building heating in the European Union compared with electrification and how blue and green hydrogen differ in terms of costs and environmental impacts. This work assesses the optimal technology mix for staying within planetary boundaries, and the influence of international cooperation and political restrictions. To perform the analysis, a bottom-up optimisation model was developed incorporating life cycle assessment constraints and covering production, storage, transport of energy and carbon dioxide, as well as grid and non-grid connected end-users of heat. It was found that a building heating system within planetary boundaries is feasible through large-scale electrification via heat pumps, although at a higher cost than the current system with abatement costs of around 200 €/ton CO2. Increasing interconnector capacity or onshore wind energy is found to be vital to staying within boundaries. A strong trade-off for hydrogen was identified, with blue hydrogen being cost-competitive but vastly unsustainable (when applied to heating) and green hydrogen being 2–3 times more expensive than electrification while still transgressing several planetary boundaries. The insights from this work indicate that heat pumps and renewable electricity should be prioritised over hydrogen-based heating in most cases and grid-stability and storage aspects explored further, while revealing a need for policy instruments to mitigate increased costs for consumers.

Global assessment of nature’s contributions to people

Synergistically maintain or enhance the numerous beneficial contributions of nature to the quality of human life is an important but challenging question for achieving Sustainable Development Goals. However, the spatiotemporal distributions of global nature’s contributions to people (NCPs) and their interactions remain unclear. We built a rapid assessment indicator framework and produced the first spatially explicit assessment of all 18 NCPs at a global scale. The 18 global NCPs in 1992 and 2018 were globally assessed in 15,204 subbasins based on two spatial indicator dimensions, including nature’s potential contribution and the actual contribution to people. The results show that most of the high NCP values are highly localized. From 1992 to 2018, 6 regulating NCPs, 3 material NCPs, and 2 nonmaterial NCPs declined; 29 regulating-material NCP combinations (54 in total) dominated 76% of the terrestrial area, and the area with few NCPs accounted for 22%; and synergistic relationships were more common than tradeoff relationships, while the relationships among regulating and material NCPs generally traded-off with each other. Transitional climate areas contained few NCPs and have strong tradeoff relationships. However, the high synergistic relationship among NCPs in low latitudes could be threatened by future climate change. These findings provide a general spatiotemporal understanding of global NCP distributions and can be used to interpret the biogeographic information in a functional way to support regional coordination and achieve landscape multifunctionality for the enhancement of human well-being.

Adjoint Q tomography with central-frequency measurements in viscoelastic medium

SUMMARY Accurate Q (quality factor) structures can provide important constraints for characterizing subsurface hydrocarbon/water resources in exploration geophysics and interpreting tectonic evolution of the Earth in earthquake seismology. Attenuation effects on seismic amplitudes and phases can be included in forward and inverse modellings by invoking a generalized standard linear solid rheology. Compared to traditional ray-based methods, full-waveform-based adjoint tomography approach, which is based on numerical solutions of the visco-elastodynamic wave equation, has the potential to provide more accurate Q models. However, applications of adjoint Q tomography are impeded by the computational complexity of Q sensitivity kernels and by strong velocity-Q trade-offs. In this study, following the adjoint-state method, we show that the Q (P- and S-wave quality factors QP and QS) sensitivity kernels can be constructed efficiently with adjoint memory strain variables. A novel central-frequency difference misfit function is designed to reduce the trade-off artefacts for adjoint Q tomography. Compared to traditional waveform-difference misfit function, this new central-frequency approach is less sensitive to velocity variations, and thus is expected to produce fewer trade-off uncertainties. The multiparameter Hessian-vector products are calculated to quantify the resolving abilities of different misfit functions. Comparative synthetic inversion examples are provided to verify the advantages of this strategy for adjoint QP and QS tomography. We end with a 3D viscoelastic inversion example designed to simulate a distributed acoustic sensing/vertical seismic profile survey for monitoring of CO2 sequestration.

A Heuristic Approach to Optimal Crowbar Setting and Low Voltage Ride through of a Doubly Fed Induction Generator

In this paper, a heuristic approach to doubly fed induction generator (DFIG) protection and low voltage ride through (LVRT) is carried out. DFIG-based wind systems are rapidly penetrating the power generation section. Despite their advantages, their direct coupling grid makes them highly sensitive to symmetrical faults. A well-known solution to this is the crowbar method of DFIG protection. This paper provides a method to determine the optimal crowbar resistance value, to ensure a strong trade-off between the rotor current and DC voltage transients. Further, since the crowbar method requires disconnection from the grid, the linear quadratic regulator (LQR) is applied to the system. This is to ensure fault ride through compliance with recent grid code requirements. The well-known PSO, as well as the recently developed African vultures optimization algorithm (AVOA), was applied to the problem. The first set of results show that for severe symmetrical voltage dips, the AVOA provides a good option for crowbar magnitude optimization, whereas PSO performed better for moderately severe dips. Secondly, when the LQR was optimized via the AVOA, it exhibited superiority over the conventional PSO-based PI controller. This superiority was in terms of rotor current transient magnitude, DC voltage transient magnitude, and reactive power steady-state ripple and were in the order of 67.5%, 20.35%, and 37.55%, respectively. When comparing the crowbar method and the LQR, it was observed that despite the LQR exhibiting superiority in terms of transient performance, the crowbar method offered a unanimously superior settling time.

Hydraulic trade-off and coordination strategies mediated by leaf functional traits of desert shrubs.

Desert shrubs play important roles in desertification control and vegetation restoration, which are particularly affected by droughts caused by climate change. However, the hydraulic strategies associated with hydraulic functional traits of desert shrubs remain unclear. Here, eight desert shrub species with different life forms and morphologies were selected for a common garden experiment at the southeast edge of the Tengger Desert in northern China to study the hydraulic strategies mediated by leaf hydraulic functional traits. Diurnal leaf water potential change, leaf hydraulic efficiency and safety, hydraulic safety margin, hydraulic capacitance, and water potential and relative water content at the turgor loss point were observed to significantly differ among species, suggesting that leaf hydraulic functional traits were strongly associated with species even when living in the same environment. Additionally, shrubs with greater leaf hydraulic efficiency had lower midday leaf water potential and leaf hydraulic safety, suggesting that leaf hydraulic efficiency had a strong trade-off with hydraulic safety and minimum leaf water potential, whereas there was also a coordination between leaf hydraulic safety and the leaf minimal water potential. Moreover, shrubs with higher leaf hydraulic capacitance had greater hydraulic safety margins, indicating coordination between leaf hydraulic capacitance and hydraulic safety margin. Overall, this study indicated that minimal daily leaf water potential, as an easily measured parameter, may be used preliminarily to predict leaf hydraulic conductivity and the resistance to embolism of desert shrubs, providing critical insights into hydraulic trade-off and coordination strategies for native shrubs as priority species in desert vegetation restoration and reconstruction.

Xylem hydraulics strongly influence the niche differentiation of tree species along the slope of a river valley in a water-limited area.

Xylem hydraulic characteristics govern plant water transport, affecting both drought resistance and photosynthetic gas exchange. Therefore, they play critical roles in determining the adaptation of different species to environments with various water regimes. Here, we tested the hypothesis that variation in xylem traits associated with a trade-off between hydraulic efficiency and safety against drought-induced embolism contributes to niche differentiation of tree species along a sharp water availability gradient on the slope of a unique river valley located in a semi-humid area. We found that tree species showed clear niche differentiation with decreasing water availability from the bottom towards the top of the valley. Tree species occupying different positions, in terms of vertical distribution distance from the bottom of the valley, showed a strong trade-off between xylem water transport efficiency and safety, as evidenced by variations in xylem structural traits at both the tissue and pit levels. This optimized their xylem hydraulics in their respective water regimes. Thus, the trade-off between hydraulic efficiency and safety contributes to clear niche differentiation and, thereby, to the coexistence of tree species in the valley with heterogeneous water availability.

Identifying interlinkages between urbanization and Sustainable Development Goals

Urbanization and Sustainable Development Goals (SDGs) are important global issues in the current “Anthropocene”. Climate change and the COVID-19 pandemic have exacerbated global urban problems and hindered the ability to meet SDGs on time, while the broad interlinkages between urbanization and the SDGs remain poorly understood. This study shows that among the interlinkages of urbanization with 17 SDGs, synergies are observed with 151 targets (89%), among which 67 (40%) have stronger synergies, and trade-offs are observed with 66 targets (39%), among which 31 (18%) have stronger trade-offs. Furthermore, the synergies and trade-offs between urbanization and the achievement of SDGs are specifically analyzed based on four fundamental interaction fields: (a) public health and social welfare equality; (b) energy consumption and economic growth; (c) natural resource use and ecological/environmental impacts; and (d) international cooperation for development. Finally, based on these analyses, we propose four recommendations for sustainable urbanization, including (a) shared well-being and spatial justice for urban and rural residents; (b) guiding green and low-carbon urban development; (c) building resilient cities; and (d) promoting multilateral cooperation in cities, which can contribute to the achievement of SDGs by 2030.

The advantage of being youngest: Education inequalities and the quantity-quality tradeoff in Pakistan

ABSTRACT We explore how sex preference affects family size, and whether there is a tradeoff between family size and educational outcomes. Taking into account the endogeneity in family size and allowing for heterogeneous effect, family size has a negative impact on measured educational outcomes. Each additional sibling reduces years of education by almost two years, decreases the probability of completing primary and secondary education, suggesting a strong quantity-quality tradeoff. Birth order has a sizeable positive effect, i.e. children in the higher birth order (later born) achieve educational outcomes. Due to the cultural son-preference in Pakistan, a strong negative education gender gap is found. However, our finding suggest that the birth order effect tends to mitigate this gender gap. Several channels are conjectured; further research is warranted.

Trade-off and synergy among ecosystem services and the influencing factors in the Ziwuling Region, Northwest China.

Ecosystem service (ES) bundle is a combination of various ecosystem services, serving as an indicator for the trade-off or synergy relationship among ecosystem services. Identifying the trade-off and synergy within ecosystem service bundles is helpful for realizing regional management and policymaking at the ES-bundle level. In this study, based on the InVEST model, the spatial composition, trade-off, and synergy of ES bundles, and their influencing factors were clarified using correlation analysis, cluster analysis, principal component analysis, and redundancy analysis. The results showed that the ESs in the Ziwuling Region (ZWLR) were generally improved from 2000 to 2017. The high-value area of soil conservation was concentrated in the northern part of the ZWLR, whereas other high-value areas of ESs were concentrated in the central and southern parts. According to the results of the cluster analysis, the ZWLR could be divided into four ES-bundles at pixel level. There was a strong tradeoff between water yield service and soil conservation in the core protected bundle, and a strong tradeoff between habitat quality, water yield service and food production in grain production bundle. The relationship between ESs in ecologi-cal transition bundle and ecologically fragile bundle was dominated by synergetic relationship. The ESs were affec-ted by both natural conditions and human activities. Vegetation cover, precipitation, and elevation had positive effects on the ESs, while temperature, the proportion of construction land, and population density had negative effects.

Strong trade-offs characterise water-energy-food related sustainable development goals in the Ganges–Brahmaputra–Meghna River basin

The United Nations’ sustainable development goals (SDGs) set ambitious policy targets for 2030 to overcome poverty while preserving the planet. These goals are not perfectly aligned; trade-offs emerge during implementation at regional and local levels, such as in a river basin. Here, we quantify important trade-offs between water, energy, and food-related SDGs in the Ganges–Brahmaputra–Meghna River basin, a climate vulnerability hotspot, using multi-objective optimisation based on detailed water resources and crop production modelling and accounting for uncertainties in the costs of water, labour, and land. The trade-off between food production and agricultural profit is strong; the amount of people fed would be reduced by more than two-thirds, were profitability maximized. However, we do see the potential to achieve higher profitability in agriculture against limited loss of food and hydropower production and limited impact on downstream environmental flows, although continued reliance on groundwater and energy, currently unsustainable, needs to be mitigated.

Organic viticulture leads to lower trade-offs between agroecosystem goods but does not improve overall multifunctionality

CONTEXTAssessing the multifunctionality of agroecosystems is crucial to design more sustainable farming systems. While it is known that organic farming benefits biodiversity and ecosystem services, how organic farming affects their multifunctionality, including agronomical, ecological as well as economic dimensions, remains poorly explored. OBJECTIVEIn this study, we investigated how individual indicators regrouped into agroecosystem goods of vineyards respond to farming systems and landscape composition. We also explored how ecosystem services resulting from agroecosystem goods respond to farming systems and landscape composition. In addition, we evaluated trade-offs and synergies between agroecosystem goods as well as between ecosystem services for each farming systems. METHODWe quantified 14 indicators corresponding to five agroecosystem goods (biodiversity conservation, soil organic matter decomposition, pest control, wine production, margin) in 20 pairs of organic and conventional vineyards. RESULTS AND CONCLUSIONOur study reveals that organic farming did not improve agroecosystem multifunctionality compared to conventional farming but led to lower trade-offs between agroecosystem goods. We found that organic systems increase supporting and regulating services but had lower provisioning service compared to conventional systems. Indeed, organic vineyards had multiple beneficial effects including higher pest control, lower production costs but produced less wine. Our results indicate a strong trade-off between pest control and wine production in both systems. In addition, conventional systems supported a negative trade-off between biodiversity conservation and wine production which was not the case of organic systems. SIGNIFICANCEOur study provides key information to further design farming systems that combine ecological, economical and agronomical performances. Further investigations are now needed to identify which combined management options maximize multiple performance of agroecosystems independently of certifications and across scales.

Land Management and Rural Development in Northwest China

In order to break away from the overreliance on a single industry and the simple supply of agricultural products, rural multifunctional research has gradually received public attention. To a certain extent, multifunctional classification governance paths can enhance rural competitiveness and land use efficiency and alleviate the problems of local poverty and unbalanced development in rural regions. Based on the theory of rural multifunctionality, this paper reveals the spatial characteristics and coordination of rural multifunctionality at the township scale, analyzes the barrier functions of different regions, and clarifies the direction of rural development using the rural assessment method, the trade-off synergy model, and the dysfunctional diagnostic model, taking Yongchang County in the western corridor of China as an example. On this basis, we further discuss the path selection of rural governance in northwest China. The results show that: (1) The spatial distribution of rural functions has pronounced heterogeneity, with better life security functions and ecological background functions, and similar spatial patterns; economic development functions are on the low side, showing the divergent characteristics of enhancement from the township center to the surrounding area. The functions of agricultural production are low, and the spatial distribution is similar to that for the living guarantee function. (2) The living guarantee function has a strong trade-off effect on the ecological background function, and the living guarantee and ecological background functions have a synergistic effect on the agricultural development function. (3) We classified types of villages according to the intensity index of village function trade-offs and clarified the functional development characteristics of each administrative village. The incompatibility of village functions caused by different demands is the root hinderance to the development of villages.

Understanding equity–efficiency interaction in the distribution of global carbon budgets

Equity and efficiency are two important factors guiding the mitigation of anthropogenic emissions to achieve the Paris climate goals. Previous studies have proposed a range of allocations of global carbon budgets, but few have quantified the equity–efficiency interaction. Based on an investigation of the existing allocation literature, this study conducts a novel analysis using a ‘mixed’ allocation ‘big-data’ framework to understand the equity–efficiency interaction in the distribution of global carbon budgets under 2 °C and 1.5 °C warming targets. At a global scale, a carbon Gini coefficient and aggregate abatement costs are used as quantitative metrics to reflect equity and efficiency, respectively. Results show an equity–efficiency frontier that reflects the opportunity for the international community to co-improve equity and efficiency on top of existing allocations. However, the frontier also features strong trade-offs to further improve equity and efficiency if national allocations are to be achieved individually. Our analysis verifies that such trade-offs are sensitively dependent on the level of global connection and integration. Linking national mitigation actions and potentials can help promote equity–efficiency synergies and contribute to the efficient achievement of the Paris Agreement's temperature and equity goals.

Dynamics of spatial associations among multiple land use functions and their driving mechanisms: A case study of the Yangtze River Delta region, China

Land use functions and their interaction analysis has been a hot topic in the field of land change science for better advancing the regional sustainable development. Previous studies focused more on the impacts of land use activities on the natural and semi-natural systems at the regional scale, ignoring the impacts of land-use on the complex social-ecological system and their dynamics at a fine scale. In this study, we applied a LUF classification framework, including agricultural production function (APF), urban-rural living function (ULF) and ecological maintenance function (EMF), to quantify multiple LUFs in Jiangsu Province, an essential part of the Yangtze River Delta region, China, from 2000 to 2020 at the grid scale. We then investigated the dynamics of spatial associations among multiple LUFs and revealed the underlying drivers of these LUFs integrating multisource data and multiple geospatial analysis methods. The results showed that APF-ULF trade-offs increased in northern Jiangsu and decreased in southern Jiangsu from 2000 to 2010; whereas these trade-offs generally increased between 2010 and 2020 across the entire region. APF-EMF trade-offs showed an opposing pattern to APF-ULF during the study period. ULF-EMF trade-offs increased from 2000 to 2020 with strong trade-offs primarily occurring in northern and southwestern Jiangsu. Land cover classes had a substantial impact on all the secondary LUFs. Vegetation cover was correlated with changes in APF and EMF, and distance factors were more important to ULF. Finally, we used the nine secondary LUFs to detect five LUF clusters and proposed distinct LUF management strategies considering the spatial heterogeneity of multiple LUFs in these LUF clusters. We also suggested the mechanisms behind apparent relationships among LUFs are considered into the formulation of land spatial planning and management strategy for facilitating the coordinated development of multiple LUFs.

Experimental insect suppression causes loss of induced, but not constitutive, resistance in Solanumcarolinense.

Spatiotemporal variation in herbivory is a major driver of intraspecific variation in plant defense. Comparatively little is known, however, about how changes in herbivory regime affect the balance of constitutive and induced resistance, which are often considered alternative defensive strategies. Here, we investigated how nearly a decade of insect herbivore suppression affected constitutive and induced resistance in horsenettle (Solanum carolinense), a widespread herbaceous perennial. We allowed replicated horsenettle populations to respond to the presence or absence of herbivores by applying insecticide to all plants in half of 16 field plots. Horsenettle density rapidly increased in response to insecticide treatment, and this effect persisted for at least 4 years after the cessation of herbivore suppression. We subsequently grew half-sibling families from seeds collected during and shortly after insecticide treatment in a common garden and found strong effects of insect suppression on induced resistance. Feeding trials in field mesocosms with false Colorado potato beetles (Leptinotarsa juncta), a common specialist herbivore, revealed that multiyear herbivore suppression drove rapid attenuation of induced resistance: offspring of plants from insect-suppression plots exhibited a near-complete loss of induced resistance to beetles, whereas those from control plots incurred ~70% less damage after experimental induction. Plants from insect-suppression plots also had ~40% greater constitutive resistance compared with those from control plots, although this difference was not statistically significant. We nonetheless detected a strong trade-off between constitutive and induced resistance across families. In contrast, the constitutive expression of trypsin inhibitors (TI), an important chemical defense trait in horsenettle, was reduced by 20% in the offspring of plants from insect-suppression plots relative to those from control plots. However, TIs were induced to an equal extent whether or not insect herbivores had been historically suppressed. Although several defense and performance traits (prickle density, TI concentration, resistance against false Colorado potato beetles and flea beetles, biomass, and seed mass) varied markedly across families, no traits exhibited significant pairwise correlations. Overall, our results indicate that, whereas the divergent responses of multiple defense traits to insect suppression led to comparatively small changes in overall constitutive resistance, they significantly reduced induced resistance against false Colorado potato beetle.