Science Enabled by Specimen Data

Cosme, M. 2023. Mycorrhizas drive the evolution of plant adaptation to drought. Communications Biology 6.

Plant adaptation to drought facilitates major ecological transitions, and will likely play a vital role under looming climate change. Mycorrhizas, i.e. strategic associations between plant roots and soil-borne symbiotic fungi, can exert strong influence on the tolerance to drought of extant plants. Here, I show how mycorrhizal strategy and drought adaptation have been shaping one another throughout the course of plant evolution. To characterize the evolutions of both plant characters, I applied a phylogenetic comparative method using data of 1,638 extant species globally distributed. The detected correlated evolution unveiled gains and losses of drought tolerance occurring at faster rates in lineages with ecto- or ericoid mycorrhizas, which were on average about 15 and 300 times faster than in lineages with the arbuscular mycorrhizal and naked root (non-mycorrhizal alone or with facultatively arbuscular mycorrhizal) strategy, respectively. My study suggests that mycorrhizas can play a key facilitator role in the evolutionary processes of plant adaptation to critical changes in water availability across global climates. Phylogenetic comparative analysis using data of 1,638 species of angiosperms and gymnosperms suggests that the evolution of plant adaptation to critical environmental change in water availability across global climates is dependent on mycorrhizas.

Clemente, K. J. E., and M. S. Thomsen. 2023. High temperature frequently increases facilitation between aquatic foundation species: a global meta‐analysis of interaction experiments between angiosperms, seaweeds, and bivalves. Journal of Ecology.

Many studies have quantified ecological impacts of individual foundation species (FS). However, emerging data suggest that FS often co‐occur, potentially inhibiting or facilitating one another, thereby causing indirect, cascading effects on surrounding communities. Furthermore, global warming is accelerating, but little is known about how interactions between co‐occurring FS vary with temperature.Shallow aquatic sedimentary systems are often dominated by three types of FS: slower‐growing clonal angiosperms, faster‐growing solitary seaweeds, and shell‐forming filter‐ and deposit‐feeding bivalves. Here, we tested the impacts of one FS on another by analyzing manipulative interaction experiments from 148 papers with a global meta‐analysis.We calculated 1,942 (non‐independent) Hedges’ g effect sizes, from 11,652 extracted values over performance responses, such as abundances, growths or survival of FS, and their associated standard deviations and replication levels. Standard aggregation procedures generated 511 independent Hedges’ g that was classified into six types of reciprocal impacts between FS.We found that (i) seaweeds had consistent negative impacts on angiosperms across performance responses, organismal sizes, experimental approaches, and ecosystem types; (ii) angiosperms and bivalves generally had positive impacts on each other (e.g., positive effects of angiosperms on bivalves were consistent across organismal sizes and experimental approaches, but angiosperm effect on bivalve growth and bivalve effect on angiosperm abundance were not significant); (iii) bivalves positively affected seaweeds (particularly on growth responses); (iv) there were generally no net effects of seaweeds on bivalves (except for positive effect on growth) or angiosperms on seaweeds (except for positive effect on ‘other processes’); and (v) bivalve interactions with other FS were typically more positive at higher temperatures, but angiosperm‐seaweed interactions were not moderated by temperature.Synthesis: Despite variations in experimental and spatiotemporal conditions, the stronger positive interactions at higher temperatures suggest that facilitation, particularly involving bivalves, may become more important in a future warmer world. Importantly, addressing research gaps, such as the scarcity of FS interaction experiments from tropical and freshwater systems and for less studied species, as well as testing for density‐dependent effects, could better inform aquatic ecosystem conservation and restoration efforts and broaden our knowledge of FS interactions in the Anthropocene.

Telford, E. M., N. Stevens, G. F. Midgley, and C. E. R. Lehmann. 2023. Nodulation alleviates the stress of lower water availability in Vachellia sieberiana. Plant Ecology.

The genus Vachellia (Fabaceae) has a pan-tropical distribution and numerous Vachellia species are currently observed to be expanding their indigenous ranges and/or are invasive. Most Vachellia species have the capacity to enhance nitrogen uptake via an N 2 -fixing rhizobial mutualism that manifests in specialized root nodule structures enabling the catalysis of atmospheric N 2 into a plant useable form. Improved understanding of nodulation may provide new insight to the changing patterns of ecological success of Vachellia species. Here, we investigated how the seedling growth, allometry and nodulation of two common Vachellia species, the arid Vachellia erioloba and the mesic Vachellia sieberiana , responded to varied levels of water availability. Seedlings were grown at 4%, 8% and 16% soil moisture content (SMC) for four months. The seedling growth and allometry of V. erioloba was unresponsive to changing water availability, and no nodulation was observed. The allometry of V. sieberiana was responsive to changing water availability and nodulation was observed; with the highest nodule biomass and growth rate recorded at 4% SMC. These patterns suggest that V. erioloba does not require the rhizobial mutualism, possibly due to lower competitive interactions between woody plants and grass in the arid savanna. Whereas, due to the competitive vegetation interactions typical in the mesic savanna, N 2 - fixation via nodule development could provide V. sieberiana a competitive advantage over grass not only in limited N conditions, but also during periods of lower water availability.

Reichgelt, T., A. Baumgartner, R. Feng, and D. A. Willard. 2023. Poleward amplification, seasonal rainfall and forest heterogeneity in the Miocene of the eastern USA. Global and Planetary Change 222: 104073.

Paleoclimate reconstructions can provide a window into the environmental conditions in Earth history when atmospheric carbon dioxide concentrations were higher than today. In the eastern USA, paleoclimate reconstructions are sparse, because terrestrial sedimentary deposits are rare. Despite this, the eastern USA has the largest population and population density in North America, and understanding the effects of current and future climate change is of vital importance. Here, we provide terrestrial paleoclimate reconstructions of the eastern USA from Miocene fossil floras. Additionally, we compare proxy paleoclimate reconstructions from the warmest period in the Miocene, the Miocene Climatic Optimum (MCO), to those of an MCO Earth System Model. Reconstructed Miocene temperatures and precipitation north of 35°N are higher than modern. In contrast, south of 35°N, temperatures and precipitation are similar to today, suggesting a poleward amplification effect in eastern North America. Reconstructed Miocene rainfall seasonality was predominantly higher than modern, regardless of latitude, indicating greater variability in intra-annual moisture transport. Reconstructed climates are almost uniformly in the temperate seasonal forest biome, but heterogeneity of specific forest types is evident. Reconstructed Miocene terrestrial temperatures from the eastern USA are lower than modeled temperatures and coeval Atlantic sea surface temperatures. However, reconstructed rainfall is consistent with modeled rainfall. Our results show that during the Miocene, climate was most different from modern in the northeastern states, and may suggest a drastic reduction in the meridional temperature gradient along the North American east coast compared to today.

Gupta, R., L. K. Sharma, M. Rajkumar, N. Mohammad, and M. L. Khan. 2023. Predicting habitat suitability of Litsea glutinosa: a declining tree species, under the current and future climate change scenarios in India. Landscape and Ecological Engineering.

Litsea glutinosa (Lour.) C.B.Rob., an evergreen tree with significant ecological and medicinal value, has seen its distribution gradually decline due to unsustainable harvesting, overexploitation, and climate change. Habitat suitability modelling can be an effective tool for the conservation and management of L. glutinosa. This study aims to predict L. glutinosa habitat suitability in India under current and future climate change scenarios. Our study identified the important predictors that affect L. glutinosa distribution. In addition, the L. glutinosa habitat suitability area and its percent difference in the current and future were assessed, and potential conservation sites were identified. This study is based on the widely used maximum entropy (MaxEnt) species distribution model (SDM). We used current and future modelled data of the sixth version of the Model for Interdisciplinary Research on Climate (MIROC6) from Coupled Model Intercomparison Projects (CMIP6) Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5 and SSP5-8.5) emission scenarios for the period (2030s, 2050s and 2070s). Results demonstrated that the MaxEnt performance is good with an area under the receiver operator characteristic (AUC/ROC) curve of 0.852. L. glutinosa distribution is most influenced by the mean diurnal range (Bio2), contributing 55.1%. Notably, under high emissions and warmer climates of the SSP5-8.5 scenario, the suitable habitat of L. glutinosa would tend to increase. Under the SSP5-8.5 scenario, the maximum area of excellent habitat is 0.298 M km 2 . The study identified the sub-Himalayan region, the central-eastern region, the northeastern ranges, and the western ghats as candidate areas for species conservation.

Campbell, L. C. E., E. T. Kiers, and G. Chomicki. 2022. The evolution of plant cultivation by ants. Trends in Plant Science.

Outside humans, true agriculture was previously thought to be restricted to social insects farming fungus. However, obligate farming of plants by ants was recently discovered in Fiji, prompting a re-examination of plant cultivation by ants. Here, we generate a database of plant cultivation by ants, identify three main types, and show that these interactions evolved primarily for shelter rather than food. We find that plant cultivation evolved at least 65 times independently for crops (~200 plant species), and 15 times in farmer lineages (~37 ant taxa) in the Neotropics and Asia/Australasia. Because of their high evolutionary replication, and variation in partner dependence, these systems are powerful models to unveil the steps in the evolution and ecology of insect agriculture.

Ripley, B. S., S. L. Raubenheimer, L. Perumal, M. Anderson, E. Mostert, B. S. Kgope, G. F. Midgley, and K. J. Simpson. 2022. CO 2 ‐fertilisation enhances resilience to browsing in the recruitment phase of an encroaching savanna tree. Functional Ecology.

CO2‐fertilisation is implicated in the widespread and significant woody encroachment of savannas due to CO2‐stimulated increases in belowground reserves that enhance sapling regrowth after fire. However, the effect of CO2 concentration ([CO2]) on tree responses to the other major disturbance in savannas, herbivory, is poorly understood. Herbivory‐responses cannot be predicted from fire‐responses, as herbivore effects occur earlier during establishment and are moderated by plant palatability and defence rather than belowground carbon accumulation.

Sotuyo, S., E. Pedraza-Ortega, E. Martínez-Salas, J. Linares, and L. Cabrera. 2022. Insights into phylogenetic divergence of Dalbergia (Leguminosae: Dalbergiae) from Mexico and Central America. Frontiers in Ecology and Evolution 10.

The pantropical genus Dalbergia includes more than 250 species. Phylogenetic studies of the group are scarce and have only included two or three species distributed in Mexico. We obtained herbarium samples of Mexican, Central American, and South American species (sourced from MEXU). In addition, sequences of GenBank accessions were used to complement the study. Using internal transcribed spacer (ITS), the matK and rbcL sequences from 384 accessions comprising species from America, Asia, and Africa were sampled to evaluate phylogenetic relationships of Mexican species and infrageneric classifications based on morphological data. Phylogenetic analyses suggest that the genus Dalbergia is monophyletic and originated in South America. The species distributed in Mexico are not a monophyletic clade but are divided into four clades with affinities to South American and Asian species clades. There is no correlation between geography and large-scale phylogeny. The estimated ages of the Mexican and Central American clades ranged from 11.32 Ma (Dalbergia granadillo clade) to 1.88 Ma (Dalbergia ecastaphyllum clade). Multiple long-distance dispersal events should be used to explain the current genus distribution.

Luo, W., J. S. Strijk, M. Barstow, and A. K. S. Wee. 2022. The role of protected areas in tropical tree conservation post-2020: A case study using threatened Dipterocarpaceae. Biological Conservation 272: 109634.

Protected areas (PAs) are key tools to prevent extinction and preserve ecosystem functions. As countries reiterated their commitment to expand the reach of PAs by up to 30 % by 2030, stronger purpose and pertinence in the establishment of PAs is needed to ensure effective conservation. In this study, we used Dipterocarpaceae as a proxy for threatened and ecologically important trees to determine the role of PAs in tree conservation and the potential shortfalls at a global scale. We quantified the overlap between the geo-referenced occurrence data of 433 Dipterocarpaceae species and the distribution of global PAs, followed by a conservation gap analysis on Borneo, the center of diversity of the family. We found that while Southeast Asia is the hotspot for species diversity and threat to Dipterocarpaceae, a high proportion of threatened species were found at the range edges of Dipterocarpaceae. Half of all the countries with Dipterocarpaceae met the Aichi Target 11 of designating at least 17 % of their land area as PAs, and most had <10 % of their total number of PAs being relevant to Dipterocarpaceae conservation. Our conservation gap analysis demonstrated that only 5.02 % of the total area of habitat (AOH) of endemic and Critically Endangered dipterocarps was formally protected, while 18.6 % of the total AOH was included in the Heart of Borneo complex. Our data highlights the need for a more effective global conservation gap analysis for threatened trees that could inform area-based conservation post-2020.

Prasetyo, E., S. Utomo, A. F. Maulana, R. Arifriana, and P. Lestari. 2022. Current Distribution of a Luxurious Wood Species, Diospyros spp. with Its Climatic Information, based on Global Biodiversity Website. Jurnal Sylva Lestari 10: 267–277.

Ebony (Diospyros spp.) is a fancy wood distributed in eastern Indonesia. D. celebica Bakh, D. lolin Bakh, D. pilosanthera Blanco, D. ebenum Koenig, D. ferrea (Wild.) Bakh and D. rumphii Bakh are categorized as “Fancy Wood Class I” in the Indonesian market. These woods are an important product with the highest tax compared to other grades. This study aimed to identify the distribution of six ebonies based on data global biodiversity web service (Global Biodiversity Information Facility) and their climatic condition based on global climate data (WorldClim). Data from the web service, species occurrence, and climatic conditions were processed using QGIS. Species occurrence data was then extracted using GBIF occurrence. Furthermore, species occurrence data was then overlaid with climate data using point sampling tools. The results found that three ebonies scattered in the tropics and three others (D. celebica Bakh, D. rumphii Bakh, D. lolin Bakh) mostly occurred in Indonesia. Annual rainfall and temperature conditions ranged from 1,722 – 4,013 mm and 23.4 – 27.2°C for the three species of ebony in Indonesia. The distribution and climatic conditions of ebony are the initial information for further research, such as the species distribution model related to climate change and the genetic conservation agenda.