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Intraspecific trait variation is a critical determinant of ecosystem processes, especially in agroecosystems where single species or genotypes exist in very high abundance. Yet to date, only a small number of studies have evaluated if, how, or why traits forming the Leaf Economics Spectrum (LES) vary within crops, despite such studies informing our understanding of: (1) the environmental factors that drive crop LES trait variation and (2) how domestication has altered LES traits in crops vs. wild plants. We assess intragenotype variation in LES traits in ‘Chardonnay’ (Vitis vinifera)—one of the world’s most commercially important crops—across a soil compaction gradient: one of the most prominent characteristics of agricultural soils that may drive crop trait variation. Our early evidence indicates that ‘Chardonnay’ traits covary along an intragenotype LES in patterns that are qualitatively similar to those observed among wild plants: resource-acquiring vines expressed a combination of high mass-based photosynthesis (Amass), mass-based dark respiration (Rmass), and leaf nitrogen concentrations (N), coupled with low leaf mass per area (LMA); the opposite set of trait values defined the resource-conserving end of the ‘Chardonnay’ LES. Traits reflecting resource acquisition strategies (Amass, Rmass, and leaf N) declined with greater bulk density, while traits related to investment in leaf construction costs (LMA) increased with greater bulk density. Our findings contribute to an understanding of the domestication syndrome in grapevines and also provide information relevant for quantifying trait-based crop responses to environmental change and gradients.

Variability in traits forming the Leaf Economics Spectrum (LES) among and within crop species plays a key role in governing agroecosystem processes. However, studies evaluating the extent, causes, and consequences of within-species variation in LES traits for some of the world’s most common crops remain limited. This study quantified variations in nine leaf traits measured across 90 vines of five common wine grape (Vitis vinifera L.) varieties at two growth stages (post-flowering and veraison). Grape traits in these varieties covary along an intraspecific LES, in patterns similar to those documented in wild plants. Across the five varieties evaluated here, high rates of photosynthesis (A) and leaf nitrogen (N) concentrations were coupled with low leaf mass per area (LMA), whereas the opposite suite of traits defined the “resource-conserving end” of this intraspecific LES in grape. Variety identity was the strongest predictor of leaf physiological (A) and morphological traits (i.e., leaf area and leaf mass), whereas leaf chemical traits and LMA were best explained by growth stage. All five varieties expressed greater resource-conserving trait syndromes (i.e., higher LMA, lower N, and lower Amass) later in the growing season. Traits related to leaf hydraulics, including instantaneous water-use efficiency (WUE), were unrelated to LES and other resource capture traits, and were better explained by spatial location. These results highlight the relative contributions of genetic, developmental, and phenotypic factors in structuring trait variation in the five wine grape varieties evaluated here, and point to a key role of domestication in governing trait relationships in the world’s crops.