Leaf economics in a three‐dimensional environment: Testing leaf trait responses in vascular epiphytes to land use, climate and tree zone

Abstract

1. The study of functional traits offers predictive power for community ecology.Particularly in cases where individual species are difficult to study, known properties of trait spectra, such as the leaf economics spectrum (LES), and traitenvironment relationships can provide crucial generalizable information that can contribute to forecasts of distributional shifts in response to the abiotic effects of climate and land use changes. 2. Vascular epiphytes have been proposed as indicators of environmental change, but we know little about the ecology of most species. Key functional trait assumptions are based on terrestrial plants; testing these in epiphytes verifies their universality and will inform applying functional traits in predicting epiphyte responses to climate and land use change.3. In this study, we use functional traits from 37 vascular epiphyte species from forests and shade coffee farms at two sites in northern Nicaragua. We compare correlations among traits and intraspecific trait variances with those of terrestrial plants and among epiphyte taxonomic groups. We also test trait responses to environmental differences between sites and land use types, and within zones of the tree. 4. We find that epiphyte leaf traits fall towards the slower end of the LES, but with about one-third lower leaf nitrogen per change in specific leaf area (SLA) relative to terrestrial herbaceous plants. Bromeliads show less relationship between these traits than other epiphyte groups and also deviate in other trait interrelationships, suggesting unique leaf construction. 5. Trait-environment relationships varied most strongly along vertical gradients within trees, but some traits, including SLA and carbon isotope ratio, also responded to land use and site differences.6. We present evidence that trait relationships established for terrestrial plants appear to translate to epiphytes, but identify some possible caveats. Strong trait response to vertical gradients within trees suggests that within-canopy shifts could provide resilience to climate and land use changes for some epiphyte species.

Impacts of altitude on plant green leaf, fresh litter, and soil stoichiometry in subtropical forests

“…We observed higher leaf K content at lower altitudes, this finding was not supported by a previous study that reported increased K uptake for plant growth in cold temperature condition (Zorb et al, 2014). This further confirmed that environmental changes, especially different climate conditions, could affect leaf traits (Richards and Damschen, 2022). Leaf C:N and C:P showed bimodal responses with altitude, contrasting the typical pattern of increasing leaf C:N and C:P with altitude (Müller et al, 2017).…”

New Proposal of Epiphytic Bromeliaceae Functional Groups to Include Nebulophytes and Shallow Tanks

“…In contrast, tree trunks and large branches are needed to support larger C 3 or CAM tanks, which may in turn be more shade tolerant. Epiphyte functional traits exhibited little variation across broad-scale environmental gradients such as with altitude [44,47], instead displaying larger differences along local tree canopy gradients [47], and with host identity which also influenced epiphytic trait values [48]. These studies highlight the large microenvironmental ranges encountered within a single ecosystem, and that a shared habitat does not infer that functional groups thrive under the same climatic conditions.…”

“…Recent studies have used vascular epiphyte functional traits to compare them to other life forms such as herbs and trees [6], to compare epiphyte traits across environments [44][45][46][47], in relation to hosts [48] and relative to vertical gradients within the canopy [47]. Because most epiphytes are non-woody and usually show reduced stem and root systems, these studies have mostly centered on leaf traits.…”

Coordination of leaf functional traits under climatic warming in an arid ecosystem

“…The two species, N. pectinate and T. terrestris, may be proxies of the two contrasting species, conservative and acquisitive, and which one can prosper more may strongly depend on different climate change scenarios [ 73 , 74 ]. The coordination and trade-offs between traits—whether and how the LES performs—may strongly depend on plant species, PFTs, ecosystems, and environmental conditions (e.g., [ 36 , 69 , 78 – 80 ]).…”