Intra-Plant Variation in Leaf Dry Mass per Area (LMA): Effects of Leaf–Shoot Orientation and Vertical Position on Dry Mass and Area Scaling

Forests, Год журнала: 2025, Номер 16(5), С. 724 - 724

Опубликована: Апрель 24, 2025

The intra-plant plasticity of leaves plays a vital role in enabling plants to adapt changing climatic conditions. However, limited research has investigated the extent leaf trait variation and biomass allocation strategies herbaceous plants. To address this gap, we collected total 1746 from 217 Lamium barbatum Siebold Zucc. measured their dry mass (M) area (A). Leaves were categorized by vertical position (upper vs. lower canopy layer) leaf–shoot orientation (east, south, west, north). ANOVA with Tukey’s HSD test was used compare differences M, A, per unit (LMA). Reduced major axis regression employed evaluate scaling relationship between M bootstrap percentile method determine exponents. data indicated that: (i) LMA, exponents versus A did not differ significantly among orientations, (ii) layer exhibited greater LMA than upper leaves, but smaller. These findings highlight that plant growth brings significant traits relationships This differs observed trees, is also critical for balancing weight load optimizing light-use efficiency, potentially enhancing stress resilience

Язык: Английский

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Revisiting the role of mean annual precipitation in shaping functional trait distributions at a continental scale

New Phytologist, Год журнала: 2023, Номер 241(5), С. 1900 - 1909

Опубликована: Дек. 22, 2023

Mean annual precipitation (MAP) varies substantially across the globe, impacting spatial distribution and structure of vegetation (Schimper, 1898). However, evidence for consistent relationships between MAP functional traits organisms in these ecosystems is equivocal. Indeed, while some early global-scale analyses reported as a key predictor plant (Wright et al., 2005; Moles 2009; Ordoñez 2009), more recent have found relatively weak (among other broad-scale climatic variables; 2014; Maire 2015; Bruelheide 2018), seemingly at odds with important role that water availability predicted to play determining success from first principles (McDowell 2008, 2022). The independent contribution shaping species traits, least global scale, has therefore remained unclear. An emerging observation trait–environment patterns become pronounced when focussing on regional scales, or within habitat types (Chelli 2019; Guerin 2022; Kambach 2023). Here, continent Australia, we empirically test our theoretical understanding relationship using an unprecedented database, AusTraits – largest harmonised continent-specific collection georeferenced trait values globally. Australia represents ideal laboratory trait–MAP several reasons. First, mean temperature (MAT) are orthogonal (r = 0.02; Fig. 1a). As such, associations can be isolated effect MAT, by design. also spans extraordinary gradient, encompassing 22nd (79 mm) 99th (7625 quantiles MAP, thereby representing all but very driest regions globe (Fig. 1b). Finally, although major land-based carbon sink (accounting c. 60% terrestrial years; Poulter 2014), there significant uncertainty regarding uptake this region, which proposed emerge number factors including poor representation drought-adaptation highly endemic structurally distinct variation model ensembles simulated prescribed fraction woody herbaceous cover (Teckentrup 2021). Altogether, re-examination would not only improve fundamental evolution distributions yield timely assessment embedded processes dynamic models (DVMs) used simulate ecosystem We selected eight widely considered capture physiological vascular plants, sufficient data were available, generated hypotheses how each respond MAP. Hypotheses derived published eco-evolutionary theories explicitly relating soil moisture and, if inferred predictions based moisture-related environmental drivers vapour pressure deficit (VPD) site productivity. invoke range including, example, tissue damage due leaf overheating, optimisation construction maximise net stand-based competition (Table 1). bivariate linear regressions (according sign relationship) overarching hypothesis being direct links strongest correlations. To establish clearer picture macroclimatic control quantify extent mediated MAT via interaction 2017). account potential responses environment woodiness, tested whether observed differed classified nonwoody. expected stronger taxa because long-lived individuals must function challenging conditions whereas nonwoody often avoid dry surviving seed. VPD1 Soil moisture2 Wang al. (2017)1 Paillassa (2020)2 Time reproductive maturity ↑ Access light Productivity1 Moisture stress2 Competition greater mesic environments1 stress places upper limit height2 Falster Jensen & Zwieniecki (2013)2 Construction cost Water transport rate Leaf turnover ↓ Photosynthetic Respiration Number offspring Competitive ability Growth-dependent mortality For taxa, was excellent (r2 ≥ 30%) Δ13C (Δ13C; C3 plants only), mass per area (LMA), maximum height (MH) nitrogen (Narea), LMA Narea decreasing MH increasing 2; 2). In addition, moderate 20%) (LA) wood density (WD), positively negatively correlated respectively. weaker 10%) Huber value (SA : LA) seed (SM), correlated, Regardless correlation strength, cases direction fitted Combining observations tended cause amount variance explained decline nonwood-related (see Materials Methods section), exception LA, increased slightly. Most notably, reduction r 2 31 % $$ {r}_{\mathrm{woody}}^2=31\% overall 26 {r}_{\mathrm{overall}}^2=26\% , much larger decrease ( 38 {r}_{\mathrm{woody}}^2=38\% vs {r}_{\mathrm{overall}}^2=2\% ), now virtually uncorrelated. These outcomes emerged because, most part, case LMA, bimodal low annuals general, interacting had minimal impact (Δ < 5 percentage points) well combined S1). 10 point increase r2 compared MAP-only SM (but nonwoody) (overall only) which, LA MH, mostly reflected steepening slope warmer climates, SM, towards climates driven main (Figs S1–S3; Table S2). Alone, SA uncorrelated ≤ remaining contrast (Moles strong manner literature Specifically, increased, systematic shift resource-conservative resource-acquisitive traits. This response prominent partial support hypothesis, exceptions where explanatory power equivalent growth forms. findings phenomenon gradients habitats (Buzzard Chelli 2023), been shown plot-based community-weighted climate (Guerin Importantly, rapid expansion database since (2022) permitted advancement upon Australian ecology present here incorporating naturally occurring communities extreme ranges rainfall gradient (including tropical rainforest) plant-construction relevant simulating DVMs such WD (Sakschewski 2015). positive followed closely analysed simultaneously. outcome qualitatively similar previous study height, wettest quarter, then predictors total (50% 21%). may Maximum achievable biophysically constrained that, else equal, taller survive wetter sites (Jensen Zwieniecki, 2013). alternative explanation average, natural selection favours benefit having higher position canopy outweighs drawback stem costs delayed reproduction intensifies (Falster Similar strongly recent, empirical analysis (Cornwell 2018). measure long-term average ratio CO2 intercellular spaces (Ci) atmosphere (Ca). According least-cost theory, procuring transpiration increases drier environments (Prentice leading reduced stomatal conductance, lower Ci, causing invest photosynthetic capacity relative (Dong line Narea, linked 2022), regardless form. Remarkably, Cornwell (2018), strength both suggesting governing behaviour similarly sensitive Separately analysing revealed differences expectations (i.e. ~ 40%) taxa. theorised productivity rates conferred cheaply constructed leaves, access light, compensates high associated lifespan leaves hypothesised advantageous arid maintain negative potentials (Wang Qualitatively, results Wright (2004), who modest after statistically controlling MAT. fact large proportion current scale intriguing. trees shrubs evergreen, meaning well-recognised trade-off obscured cold-deciduous. even separately evergreen deciduous (2004) 22% LMA. points driving economic strategies perhaps beyond. By contrast, just general tendency group. Trait interdependencies, trade-offs, underpin analysed. connectivity TRY seen (Flores-Moreno 2019). Alternatively, group employs wider variety tolerate harsher variable environments, occupying benign positions understorey employing dormancy bet-hedging strategy bank, many herbs (Dwyer Erickson, 2016). Increasing reliability accompanied development trait-based approaches, allow directly presiding (De Kauwe Our harmonised, data-rich provides clear, albeit correlation-based, consequently, impetus incorporated into next generation DVM simulations continent. integration depends mechanistically describe emerge. end, note correlations Δ13C) lack linking them moisture, instead VPD open question, however, generalisable regions, biogeographical (Gallagher While it difficult address definitively, postulate underlying mechanisms along systems, weaken emergent patterns. geologically old glaciation, Europe North America, focus research, experienced substantial glaciation Last Glacial (c. 21 kya). disequilibrium contemporary potentially weakening trait–climate (Squires, 1988; Svenning Skov, 2007; Seliger Trait–MAP apparent comparison northern hemisphere, small experiences freezing winter temperatures (Orians Milewski, 2007). Consequently, typically limited seasonal cold periods, emphasising selective function. do rule out mediator however. demonstrated size-based like acute temperatures, simple conducted invites further investigation dataset treatment species-by-site combinations totality across-site intra-specific variation, does partition components (Ackerly Cornwell, Identifying sources implications historically, resilient will future change 2020). Second, evaluated independently one another, operates multiple simultaneously, adaption drought achieved through different Further investigate covariance amongst (Brown 2022) insight interact confer fitness under S4). manner, local-scale coexistence diversity, magnitude itself dependent (Andrew triangular signal dense Substantial given band could go way explain others 2005) observed. challenge frameworks, therefore, predict central 2017; 2017, 2023; Xu 2021), likely diversity strategies, occur regime. Using correlations, guided quantitative literature, long-lived, coordinated scope reveal species-diverse demonstrate continental-scale act experiments phylogenetic history and/or covariation (e.g. orthogonality Australia). advocate re-focussing geographical span interest covariates (Kambach (v.4.1.0; 2021) containing over 1000 000 individual records 30 offshore islands territories). It collation growing any whole queried represent dimensions ecophysiological strategy, distributed (Supporting Information Figs S5, S6), about isotope δ l 13 C {\updelta}_{\mathrm{l}}^{13}\mathrm{C} (MH), LA), (LA), (SM) (WD). Sampling bias unavoidable compilations assemble datasets contributors their own research interests sampling (Keller 2023) case, include intentionally sampled known Schulze 1998; S5). Nevertheless, here, dominated dataset, thus, confident benefits assessing continental data. Because interested climate, filtered geospatial information. order sample 'natural' AusTraits, made unmanipulated situ. words, excluded originating field, glasshouse experiments, herbarium expert opinion. remove recorded metapopulation sites) species-level ensure sites, present, adequately represented. Removing 5% field-observed traits), 40% either level. studies assigned populations flora descriptions respective dataset. removed S7) they retained, former case. Measurement protocols compound leaflet whole-leaf scale. framework predicting conductance leaf–atmosphere boundary layer species, determined Thus, minimise varying measurement, identified measured measurement protocol unknown. Then, only, 'leaf_compoundness' classifies 'simple', 'compound' 'simple compound', assign assuming compound' compound. compoundness unknown omitted. sum, 2000 17 500 process. approaches check errors assess dataset-level errors, against visually inspected obvious discrepancies. observations, especially those contributors, various metrics reflecting occupy identify erroneous observations. process led removal n 15), unusually overall. duplication taxon obtained shared source no reason. influence form 'woodiness_detailed' trait, compiled Wenk (2023). describes presence vertical secondary xylem 'true wood') thus separates categories. study, did view se. Instead, pooled information two possible groups 'woody' 'nonwoody'. group, erect habit lignified category single capturing half available. comparison, captured diverse forms, (being dominant group) tussocks, graminoids palmoid among classifications. Some taxonomic monocots ferns occasionally produce wood-like material despite lacking xylem. classification influenced analysis, twice, definition 'woody_like_stem' 'nonwoody' second There minor performance latter so primarily report set analyses, qualitative difference interpretation (Tables S2, S3). Although specific aim variables atmospheric availability. mediates Climate sources, provided variables. warmest coldest seasonality Worldclim resolution arc seconds 1 km equator), evapotranspiration Envirem monthly 1981 2010 CHELSA seconds. VPD, averaged months find VPD. index calculated dividing evapotranspiration. extracted corresponding peninsular coastal recorded, cases, nearestLand seegsdm package (Golding Shearer, nearest non-NA cell km. If correction still data, included statistical analyses. Overall, quantitatively replacing notable responded quarter. combined, distinguishes short-statured Mediterranean forbs experiencing productive, summer monsoonal rainforests S8). Moreover, suggest MI quarter separated combined. Supporting Information, findings. scales within-site variation. Variation assumed heterogeneity, local strategies. overlaying grid continent, site. Before site-level (or maximum, MH) yielding 400–5000 unique depending it. means sometimes summarised time. approach accounted uneven intensity summarising taxon-level cell. transformed meet assumption normality regression. log-transformed sqrt-transformed available regressed ordinary least-squares assessed Pearson coefficient understand Given sizes involved P-values significant, them. variables, temperature, complex comparative fit. exhibit than repeated described above separately. forms omitted permit explore possibility nonlinear curvature fit again additional quadratic parameter term significantly improved fits S2–S4). concave-up whereby steep until 1200 mm began slightly Discussions Will Mark Westoby, David Coleman John Dwyer enriched results. funded grant awarded Eucalypt (Eucalypt futures: change) DSF PAV grants Research Council (DP200100555, FT160100113). thank AusTraits. project received investment (doi: 10.47486/TD044, 10.47486/DP720) Data Commons (ARDC). ARDC National Collaborative Infrastructure Strategy (NCRIS). Open publishing facilitated University New South Wales, part Wiley - Wales agreement Librarians. None declared. IRT conceived original idea concept PAV, EHW, RVG, SMW IJW. review theory. assistance SMW. writing manuscript. DSF, IJW assisted drafting All authors approved final draft code GitHub (https://github.com/traitecoevo/aus_trait_gradients). v.4.1.0 https://zenodo.org/doi/10.5281/zenodo.3568417. S1 Interaction trait-mean S2 S3 S4 Pair-wise matrix S5 Geographical S6 respect Whittaker's biomes. S7 Comparison retained analysis. S8 (MAP)-only MAP-mean models. Model woody-like grouped regressions. Please note: responsible content functionality supplied authors. Any queries (other missing material) should directed Phytologist Central Office. publisher supporting content) author article.

Язык: Английский

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Global photosynthetic capacity jointly determined by enzyme kinetics and eco-evo-environmental drivers

Fundamental Research, Год журнала: 2024, Номер unknown

Опубликована: Фев. 1, 2024

Accurate understanding of global photosynthetic capacity (i.e. maximum RuBisCO carboxylation rate, Vc, max) variability is critical for improved simulations terrestrial ecosystem photosynthesis metabolisms and carbon cycles with climate change, but a holistic assessment remains lacking. Here we hypothesized that max was dictated by both factors temperature-associated enzyme kinetics (capturing instantaneous ecophysiological responses) the amount activated (indexed standardized at 25 ℃, max25), compiled comprehensive dataset (n = 7339 observations from 428 sites) hypothesis testing. The data were derived leaf gas exchange measurements using portable systems. We found semi-empirical statistical model considering explained 78% variability, followed 55% alone. This outperformed current theoretical optimality predicting (67%), primarily due to its poor characterization on max25 (3%). Further, demonstrated that, in addition climatic variables, belowground resource constraint machinery built-up directly structures biogeography key missing mechanism improving modelling variability. These findings improve mechanistic provide an important basis benchmark process-based models cycling under change.

Язык: Английский

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Genetically correlated leaf tensile and morphological traits are driven by growing season length in a widespread perennial grass

American Journal of Botany, Год журнала: 2024, Номер 111(5)

Опубликована: Май 1, 2024

Leaf tensile resistance, a leaf's ability to withstand pulling forces, is an important determinant of plant ecological strategies. One potential driver leaf resistance growing season length. When seasons are long, strong leaves, which often require more time and resources construct than weak may be advantageous when short. Growing length other conditions also impact the morphological traits that underlie resistance.

Язык: Английский

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The leaf-scale mass-based photosynthetic optimization model better predicts photosynthetic acclimation than the area-based

AoB Plants, Год журнала: 2024, Номер 16(5)

Опубликована: Авг. 19, 2024

Leaf-scale photosynthetic optimization models can quantitatively predict acclimation and have become an important means of improving vegetation land surface models. Previous generally been based on the optimality assumption maximizing net assimilation per unit leaf area (i.e. area-based optimality) while overlooking other assumptions such as dry mass mass-based optimality). This paper compares predicted results to different environmental conditions between The predictions are then verified using observational data from literatures. model better growth light intensity, air temperature CO

Язык: Английский

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