Biology subjects

Veldhuisen, L. N.

Publications and source records attributed to Veldhuisen, L. N..

6 recordsLinked to original sources

bioRxiv2026

Testing fundamental hypotheses of colonization success in the ferns

Background and AimsNon-native species are now ubiquitous members of regional floras. The factors that lead to establishment and dominance of non-native species are continuously debated. Fundamental hypotheses about drivers of invasion success include the role of phylogeny, polyploidy, genome size, and rapid niche evolution. These hypotheses have been tested in the seed plants, but ferns, the second largest group of vascular plants, have rarely been considered in these analyses, despite making up a non-trivial portion of non-native floras. MethodsWe compiled a dataset of global non-native ferns and categorized them along the invasion spectrum using descriptions from the literature and natural history collections. Using this dataset, we assessed I) the taxonomic diversity and phylogenetic clustering of non-native ferns, II) the geographic distribution of fern introductions, testing for shifts in climatic niches, and III) test for the association of invader traits across the invasion continuum, including smaller genome sizes and higher ploidal levels. Key ResultsWe generated a dataset that includes 83 taxa; of these, we classified 18 as casual, 35 as naturalized (but not invasive), and 30 as invasive. Using this dataset, we found I) weak or no phylogenetic clustering of non-native ferns, II) some regions are overrepresented as sources and recipients of introductions, III) climatic niches are often conserved between native and introduced ranges, but can differ between introductions, IV) naturalized ferns have smaller genomes, and V) invaders have higher ploidal levels. ConclusionsWe integrated regional floras, occurrence and climate data, phylogeny, and cytology to test fundamental hypotheses regarding the colonization success of ferns. This study provides insights into the ecological, genomic, and phylogenetic features associated with the colonization of new habitats by non-native ferns, a largely overlooked portion of non-native plant taxa.

evolutionary biology↗

bioRxiv2025

Phylogenetic patterns over sixty-five years of vegetation change across a montane elevation gradient

Phylogenetic diversity is an important axis of biodiversity associated with ecosystem stability and productivity. However, climate change will threaten phylogenetic diversity when extinctions are phylogenetically clustered. Despite the importance of phylogenetic diversity for current and future ecosystems, and the potential unique insights it offers into communities, few studies have quantified its long-term changes. Here, we leverage a dataset spanning approximately 65 years and 1500 m of elevation in the Colorado Rocky Mountains to test for changes in phylogenetic diversity in angiosperm communities. We included four community types (sagebrush, spruce-fir, upland-herb, alpine), which vary in the direction and magnitude of changes in species richness over this period. We tested whether individual species responses to climate change could be predicted by phylogeny, including changes to abundance, constancy (% of sites occupied), and elevational range. We did not find phylogenetic signal in abundance change in any community, but we did find phylogenetic signal in both constancy shifts in alpine and elevational shifts in sagebrush communities. We then tested for changes in phylogenetic diversity across time for each community type. We found that phylogenetic diversity changed in the same direction as species richness in the sagebrush community, where both declined, and in the upland-herb, where both increased, with important roles for both species gains and losses in community phylogenetic composition. The alpine community did not change in phylogenetic diversity, although richness declined, while the spruce-fir community increased in phylogenetic diversity but did not change in richness, emphasizing the potential for changes in different aspects of diversity to be decoupled. Our work highlights that the impacts of climate change vary across communities, and that phylogeny is shaping changes in certain systems. Given the importance of phylogenetic diversity to ecosystem function, long term studies are essential for understanding how climate change impacts phylogenetic diversity in distinct community types with unique responses to climate change.

ecology↗

bioRxiv2025

Phylogenetic diversity and species diversity are decoupled under experimental warming and cooling in Rocky Mountain plant communities

AimNearly 8% of species could go extinct from climate change; many organisms are already experiencing declines in abundance, local extinction, and range shifts. How such changes impact community diversity is an open question in most systems. Whether changes in phylogenetic diversity parallel those in traditional diversity metrics is also often unknown. We used experimentally transplanted plant communities to ask how different aspects of community diversity change with environmental factors across elevation, and whether phylogenetic relationships predict individual species responses to change. LocationWe experimentally transplanted subalpine plant communities down and upslope across 400 m of elevation at the Rocky Mountain Biological Laboratory, Gothic, CO, USA, to simulate climate warming and cooling. MethodsWe identified how experimental warming and cooling impacted community diversity by testing for differences in species richness, Shannon diversity, and phylogenetic diversity among transplant treatments. We tested for phylogenetic signal in each species change in percent cover among treatments. Finally, we assessed if aspects of species rarity (and thus their putative extinction risk) predicted post-transplant change independently or in addition to their phylogenetic relationship within the community. ResultsWe found that species richness and Shannon diversity decreased in cooled treatments and increased in some warmed treatments. In contrast, phylogenetic diversity increased in the cooled treatment and did not change in the warmed treatments. Individual species changes in response to warming and cooling were not correlated with phylogeny or aspects of rarity. Main conclusionsOur results suggest that species losses in cooled treatments are phylogenetically dispersed, increasing phylogenetic diversity, even as richness and Shannon diversity decline. Increasing richness and Shannon diversity in warmed treatments suggests that new species from across the phylogeny can colonize after transplantation, leading to stability in phylogenetic diversity under warming at this time scale, with further change likely as extinction debts are paid.

ecology↗

bioRxiv2024

Rare species do not disproportionately contribute to phylogenetic diversity in a subalpine plant community

Premise of the studyWorldwide, 36% of all plant species are exceedingly rare, and are at the highest risk of extinction. Extinction risk has also been observed to be phylogenetically clustered, threatening the loss of lineages that contribute unique evolutionary diversity to communities. Rare plants contributions to phylogenetic diversity are largely unknown, however. We investigate whether rare species (as measured by local abundance and range size) contribute disproportionately to phylogenetic diversity in a subalpine plant community. MethodsWe collected abundance data at three sites in Washington Gulch near the Rocky Mountain Biological Laboratory (RMBL, Gothic, Colorado, USA) in 2021 and 2022. We then calculated range size for each species. We calculated phylogenetic signal for abundance and range size, compared community phylogenetic metrics weighted by range size and abundance to unweighted metrics, and quantified the change in phylogenetic diversity when removing single species and groups of species ranked by rarity. Key resultsWe found phylogenetic signal for abundance, but not range size. There was no difference between rarity-weighted and unweighted phylogenetic diversity metrics. Finally, phylogenetic diversity did not decline more when we removed single rare species and groups of rare species than when we removed single common species and groups of common species. ConclusionsOverall, we found that rare species do not disproportionately contribute to phylogenetic diversity. This suggests that rare species likely provide phylogenetic redundancy with common species, and losing rare species may not cause disproportionate drops in phylogenetic diversity in this system.

ecology↗

bioRxiv2023

Phylogenetic diversity of flowering plants declines throughout the growing season across a subalpine elevational gradient

Phylogenetic diversity is an important axis of biodiversity associated with many ecosystem functions, but its variation over time in temperate communities has rarely been explored. Plants flowering phenology is key for reproduction: it determines synchrony among plants, mutualists, antagonists, and favorable environmental conditions. Individual species flowering phenologies combine to determine which species flowers co-occur in time and space to form co-flowering communities. We recorded plants flowering phenology across elevations in the Colorado Rocky Mountains and predicted: 1) flowering species will form subsets of co-flowering species, 2) groups of co-flowering species will be more distantly related than the broader community, 3) marginal early and late season conditions will constrain flowering to species groups that are less phylogenetically diverse and 4) the entire community will have higher phylogenetic diversity at higher elevations. We identified co-flowering groups using a network analysis and quantified their phylogenetic diversity. Co-flowering communities had higher phylogenetic diversity early in the season and at higher elevations, but became less diverse by all metrics at the end of the season across elevations. Our results indicate that phylogenetic diversity varies consistently across the season and that conditions in the late season and at low elevations might constrain diversity.

ecology↗

bioRxiv2022

Description of Life History & Reproductive Size Threshold in Three High Elevation Puya (Bromeliaceae)

AO_SCPLOWBSTRACTC_SCPLOWThe Andes are a hotspot for biodiversity and high species endemism for both plants and animals. The genus Puya (Bromeliaceae) lives throughout the Andes, including puna and the paramo ecosystems above 3500m. Here, we studied the life history and reproductive size thresholds in three species of Puya (P. raimondii, P. cryptantha and P. goudotiana): P. raimondii in the Bolivian puna, and P. cryptantha and P. goudotiana in the Colombian paramo. We collected data on threshold size at flowering and clonal reproduction. All three species were found to have a consistent minimum size at flowering, while only P. cryptantha demonstrated a minimum size for clonal reproduction. No such evidence was found for P. goudotiana. We also found a positive correlation between leaf length and fruit number for P. goudotiana and P. cryptantha. Our data supported that P. raimondii is fully semelparous and indicated that P. goudotiana and P. cryptantha may be semi-semelparous.

ecology↗