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• Resource-use strategies are hypothesized to evolve along climatic gradients. However, our understanding of the environmental factors driving divergent evolution of resource-use strategies and the relationship between trait genetic variation and phenotypic plasticity is far from complete. Using the Mediterranean tree Quercus faginea as study system, we tested the hypothesis that a conservative resource-use strategy with increased drought tolerance and reduced phenotypic plasticity has evolved in areas with longer and more severe dry seasons. • We conducted a glasshouse experiment in which we measured leaf morphological, physiological, growth and allocation traits in seedlings from 10 range-wide climatically contrasting populations, grown under two different watering treatments. • Both univariate and multivariate analyses revealed a genetic gradient of resource-use strategies and phenotypic plasticity associated with provenance climate. In particular, populations from harsher (drier and colder) environments had more sclerophyllous leaves, lower growth rates, better physiological performance under dry conditions and reduced multi-trait phenotypic plasticity compared to populations from more mesic and milder environments. • Our results suggest that contrasting precipitation and temperature regimes play an important role in the adaptive intraspecific evolution of multivariate phenotypes and their plasticity, resulting in coordinated morphology, physiology, growth and allometry according to alternative resource-use strategies.

The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global data sets. However, theory suggests that native and invasive species occurring in low‐resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource‐use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five mediterranean‐climate regions, which are drought prone and increasingly threatened by human activities, including the introduction of exotic species. Traits differed strongly across the five regions. In regions with functional differences between native and invasive species groups, invasive species displayed traits consistent with high resource acquisition; however, these patterns were largely attributable to differences in life form. We found that species invading mediterranean‐climate regions were more likely to be annual than perennial: three of the five regions were dominated by native woody species and invasive annuals. These results suggest that trait differences between native and invasive species are context dependent and will vary across vegetation communities. Native and invasive species within annual and perennial groups had similar patterns of carbon assimilation and resource use, which contradicts the widespread idea that invasive species optimize resource acquisition rather than resource conservation.

Realizing sustainable development has become a global priority. This holds, in particular, for agriculture. Recently, the United Nations launched the Sustainable Development Goals (SDGs), and the Nineteenth National People’s Congress has delivered a national strategy for sustainable development in China—realizing green development. The overall objective of Agriculture Green Development (AGD) is to coordinate “green” with “development” to realize the transformation of current agriculture with high resource consumption and high environmental costs into a green agriculture and countryside with high productivity, high resource use efficiency and low environmental impact. This is a formidable task, requiring joint efforts of government, farmers, industry, educators and researchers. The innovative concept for AGD will focus on reconstructing the whole crop-animal production and food production-consumption system, with the emphasis on high thresholds for environmental standards and food quality as well as enhanced human well-being. This paper addresses the significance, challenges, framework, pathways and potential solutions for realizing AGD in China, and highlights the potential changes that will lead to a more sustainable agriculture in the future. Proposals include interdisciplinary innovations, whole food chain improvement and regional solutions. The implementation of AGD in China will provide important implications for the countries in developmental transition, and contribute to global sustainable development.

• The degree of plant iso/anisohydry is a popular framework for characterising species-specific drought responses. However, we know little about associations between below-ground and above-ground hydraulic traits as well as the broader ecological implications of this framework. • For 24 understory shrub species in seasonally dry subtropical coniferous plantations, we investigated contributions of the degree of isohydry to species’ resource economy strategies, abundance, and importance value, and quantified the hydraulic conductance (K h) of above-ground and below-ground organs, magnitude of deep water acquisition (WAdeep), shallow absorptive root traits (diameter, specific root length, tissue density), and resource-use efficiencies (A max, maximum photosynthesis rate; PNUE, photosynthetic nitrogen-use efficiency). • The extreme isohydric understory species had lower wood density (a proxy for higher growth rates) because their higher WAdeep and whole-plant K h allowed higher A max and PNUE, and thus did not necessarily show lower abundance and importance values. Although species’ K h was coordinated with their water foraging capacity in shallow soil, the more acquisitive deep roots were more crucial than shallow roots in shaping species’ extreme isohydric behaviour. • Our results provide new insights into the mechanisms through which below-ground hydraulic traits, especially those of deep roots, determine species’ degree of isohydry and economic strategies.

1. Current biodiversity declines in species-rich grasslands are connected with the cessation of management, eutrophication and the expansion of dominant grass species. One of the theoretical mechanisms limiting biodiversity loss is the ability of subordinate species to avoid competitive exclusion by seasonal niche separation from dominant species. Here, we explore how seasonality underpins the maintenance of diversity in temperate meadows under different management regimes and competition intensities in relation to species functional traits. 2. We studied eight different communities in a long-term meadow experiment that manipulated mowing, fertilization and dominant species (Molinia caeruiea) removal. In each community, species-specific trait and biomass data were taken five times during the year to test whether seasonal variation in species composition and functional strategies enable species to coexist. 3. Mown unfertilized meadows exhibited pronounced seasonal variations in community composition and structure, linked to differences in resource-use strategies between mid-summer dominants and the spring and autumn subordinates. Higher specific leaf area and foliar nitrogen concentration in the fast-growing dominants, and increased water use (δ¹³C) and nutrient acquisition (δ¹⁵N) efficiency in resource-retentive subordinates, best predicted their temporal niche separation. Seasonal segregation of species with contrasting strategies increased after mowing cessation, and the resulting summer dominance of Molinia. Conversely, the seasonal dynamics were markedly reduced by fertilization, promoting tall grasses over sedges and forbs throughout the entire year, thereby decreasing the overall taxonomic and functional diversity. When Molinia was removed the compositional changes during the season became less pronounced, being significant only in mown unfertilized plots. 4. Synthesis. Seasonal shifts in community composition reduced the competitive interactions and promoted the coexistence of dominant and subordinate species. Seasonality reversed the negative mid-summer diversity-productivity relationship with a positive one during the spring and autumn, and seasonality only prevented diversity loss in unfertilized conditions possibly because competition is most intense in summer. In fertilized meadows, subordinate species are not able to escape competitive exclusion by shifting their phenoiogical peaks to the spring or autumn periods because asymmetric competition is intense over the entire growing season. Studying seasonal dynamics is key to understanding the maintenance of grassland diversity under ongoing land use change.

Studies in disturbed, resource-rich environments often show that invasive plants are more productive than co-occurring natives, but with similar physiological tradeoffs. However, in resource-limited habitats, it is unclear whether native and invasive plants have similar metabolic constraints or if invasive plants are more productive per unit resource cost – that is, use resources more efficiently. Using a common garden to control for environment, we compared leaf physiological traits relating to resource investments, carbon returns, and resource-use efficiencies in 14 native and 18 nonnative invasive species of common genera found in Eastern North American (ENA) deciduous forest understories, where growth is constrained by light and nutrient limitation. Despite greater leaf construction and nitrogen costs, invaders exhibited greater instantaneous photosynthetic energy-use efficiency (PEUE) and marginally greater photosynthetic nitrogen-use efficiency (PNUE). When integrated over leaf lifespan (LL), these differences were magnified. Differences in efficiency were driven by greater productivity per unit leaf investment, as invaders exhibited both greater photosynthetic abilities and longer LL. Our results indicate that woody understory invaders in ENA forests are not constrained to the same degree by leaf-based metabolic tradeoffs as the native understory flora. These strategy differences could be attributable to pre-adaptation in the native range, although other explanations are possible

Microclimatic conditions change dramatically as forests age and impose strong filters on community assembly during succession. Light availability is the most limiting environmental factor in tropical wet forest succession; by contrast, water availability is predicted to strongly influence tropical dry forest (TDF) successional dynamics. While mechanisms underlying TDF successional trajectories are not well understood, observational studies have demonstrated that TDF communities transition from being dominated by species with conservative traits to species with acquisitive traits, the opposite of tropical wet forest. Determining how functional traits predict TDF tree species’ responses to changing environmental conditions could elucidate mechanisms underlying tree performance during TDF succession. We implemented a 6-ha restoration experiment on a degraded Vertisol in Costa Rica to determine (1) how TDF tree species with different resource-use strategies performed along a successional gradient and (2) how ecophysiological functional traits correlated with tree performance in simulated successional stages. We used two management treatments to simulate distinct successional stages including: clearing all remnant vegetation (early-succession), or interplanting seedlings with no clearing (mid-succession). We crossed these two management treatments (cleared/interplanted) with two species mixes with different resource-use strategies (acquisitive/conservative) to examine their interaction. Overall seedling survival after 2 yr was low, 15.1–26.4% in the four resource-use-strategy × management-treatment combinations, and did not differ between the management treatments or resource-use-strategy groups. However, seedling growth rates were dramatically higher for all species in the cleared treatment (year 1, 69.1% higher; year 2, 143.3% higher) and defined resource-use strategies had some capacity to explain seedling performance. Overall, ecophysiological traits were better predictors of species’ growth and survival than resource-use strategies defined by leaf and stem traits such as specific leaf area. Moreover, ecophysiological traits related to water use had a stronger influence on seedling performance in the cleared, early-successional treatment, indicating that the influence of microclimatic conditions on tree survival and growth shifts predictably during TDF succession. Our findings suggest that ecophysiological traits should be explicitly considered to understand shifts in TDF functional composition during succession and that using these traits to design species mixes could greatly improve TDFrestoration outcomes.

1. Plastic responses to spatiotemporal environmental variation strongly influence species distribution, with widespread species expected to have high phenotypic plasticity. Theoretically, high phenotypic plasticity has been linked to plant invasiveness because it facilitates colonization and rapid spreading over large and environmentally heterogeneous new areas. 2. To determine the importance of phenotypic plasticity for plant invasiveness, we compare well-known exotic invasive species with widespread native congeners. First, we characterized the phenotype of 20 invasive-native ecologically and phylogenetically related pairs from the Mediterranean region by measuring 20 different traits involved in resource acquisition, plant competition ability and stress tolerance. Second, we estimated their plasticity across nutrient and light gradients. 3. On average, invasive species had greater capacity for carbon gain and enhanced performance over a range of limiting to saturating resource availabilities than natives. However, both groups responded to environmental variations with high albeit similar levels of trait plasticity. Therefore, contrary to the theory, the extent of phenotypic plasticity was not significantly higher for invasive plants. 4. We argue that the combination of studying mean values of a trait with its plasticity can render insightful conclusions on functional comparisons of species such as those exploring the performance of species coexisting in heterogeneous and changing environments.

Our understanding of terrestrial nitrogen (N) cycling is changing as new processes are uncovered, including the sources, turnover and losses of N from ecosystems. We integrate recent insights into an updated N‐cycling framework and discuss how a new understanding integrates eco‐evolutionary dynamics with nutrient cycling. These insights include (a) the significance of rock weathering as a biologically meaningful N source to plants and microbes; (b) the lack of consistent N limitation of organic matter decomposition by soil microbes; (c) species‐specific variation in plant N limitation; and (d) how fire effects on soil N shift with ecosystem properties. Using an eco‐evolutionary framework and revised knowledge of N cycling, we describe how (a) rock N weathering could have contributed more strongly to gradients in soil N availability than previously recognized, (b) evolution and co‐evolution of plant and soil microbial resource‐use traits underlie whether decomposition and production are N‐limited, and (c) the effects of fire on soil N pools are mediated by composition of plant species and time‐scale. Our revised framework of N cycling provides a way forward for improving biogeochemical models to more accurately estimate rates of plant production and decomposition, and total soil N. A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.

Family caregiving is an increasingly important component of care for patients and the elderly. The aim of this study is to characterize the burden of family caregiving among employed adults. Employed adults (≥18 years) from the 2013 US National Health and Wellness Survey (NHWS) were classified as family caregivers if they reported currently caring for at least one adult relative. Chi-square tests and one-way analyses of variance assessed whether employed caregivers, weighted to the US population, differed from employed non-caregivers on behavioral characteristics, workplace productivity, and health care resource utilization. Eight million workers were family caregivers in the United States, more often female than male (51% vs. 49%, < 0.05), and 53% were between 40 and 64 years of age. Eighteen percent of caregivers were Hispanic compared with 15% of non-caregivers ( < 0.05). Similar behavioral characteristics between caregivers and non-caregivers included daily alcohol consumption (6% vs. 5%) and lack of vigorous exercise (25% vs. 29%), but caregivers had a higher prevalence of smoking (26% vs. 19%, < 0.05). Caregivers reported a higher mean percentage of work time missed (8% vs. 4%, < 0.05) and greater productivity impairment (24% vs. 14%, < 0.05). Some form of depression was reported by 53% of caregivers compared with 32% of non-caregivers ( < 0.05), and more caregivers had self-reported insomnia than non-caregivers (46% vs. 37%, < 0.05). The number of self-reported diagnosed comorbidities was higher among caregivers compared with that of non-caregivers (5.0 vs. 3.1, < 0.05), as was the mean number of outpatient visits in the previous 6 months (4.1 vs. 2.7, < 0.05). Family caregiving is associated with a multidimensional burden that impacts caregivers and has implications for employers and the health care system. Clinicians and employers need to recognize and understand this burden. Characterization of caregivers as reported in this study can inform development of targeted programs to help mitigate the burden.