Isotria medeoloides, a North American Threatened Orchid: Fungal Abundance May Be as Important as Light in Species Management

The management of endangered or threatened plant species is difficult if protocols are not developed to propagate species for the purpose of restoration or the enhancement of existing populations. The management of endangered and threatened orchids is especially difficult because of the obligate interactions between orchids and orchid mycorrhizal fungi. Isotria medeoloides is a federally threatened forest-dwelling orchid species with a wide distribution in eastern North America. Seeds have not been successfully germinated and current management is based primarily on using subcanopy thinning to increase light in areas where monitoring demonstrates that populations are declining. We report the results of long-term monitoring efforts, canopy thinning, and orchid mycorrhizal fungus abundance studies at two locations in Virginia. The declining populations responded positively to the experimental and natural thinning of the canopy. At one site, the response was the result of understory canopy thinning. At the second site, the response was due to the natural death of a canopy tree. In light of the dramatic increase in fungal abundance following death of the canopy tree, we propose the Fungal Abundance Hypothesis as an additional approach to the management of endangered plant species. The removal of canopy trees in or adjacent to Isotria populations results in an increase in dead belowground biomass (i.e., roots of the dead canopy tree) that provides substrates for microbial growth, including orchid mycorrhizal fungi, that benefit Isotria.

Control of browning during seed germination of Meizotropis pellita: a rare and an endangered plant

Meizotropis pellita is a rare, endangered and threatened plant species found in Patwadanger forest. In nature this species grows from rootstock in precise and sensitive habitats. However, phenolic compounds provoke browning reaction which is responsible for lethal browning in plant tissue culture and hindering in vitro germination. The aim of this study was to minimize the effect of phenolic compound during seed germination. We evaluate different antibrowning treatments in Meizotropis pellita seeds. The seeds were pretreated in Polyvinylpyrrolidone and then treated seeds were cultured on MS media and sterilized seeds were directly inoculated on PVP containing MS media. These culture media incubate under dark and light conditions at different durations respectively. Our results showed that addition of antibrowning agent, PVP inhibit onset of browning. Dark and light condition also played a crucial role on onset of browning. Delayed and low intensity of browning were observed in case of seeds that were inoculated on MS media containing PVP and were kept in dark. The present research offers a positive in vitro seed germination protocol for Meizotropis pellita conservation.

Natural and Historical Heritage of the Lisbon Botanical Gardens: An Integrative Approach with Tree Collections

Botanical gardens have long contributed to plant science and have played a leading role in ex situ conservation, namely of threatened tree species. Focusing on the three botanical gardens of Lisbon (i.e., Botanical Garden of Ajuda—JBA, Lisbon Botanical Garden—JBL, and Tropical Botanical Garden—JBT), this study aims to reveal their natural heritage and to understand the historical motivations for their creation. Our results showed that these gardens contain a total of 2551 tree specimens, corresponding to 462 taxa, within 80 plant families. Of these, 85 taxa are found in the three gardens, and more than half of the taxa are hosted in JBL (334 taxa), whereas 230 and 201 taxa were recorded in JBT and JBA, respectively. The motivations for the creation of each garden are reflected in the different geographic origins of the trees they host in their living collections. The Palearctic species are dominant in JBA and JBL, and Tropical trees prevail in JBT. With more than 250 years of history, these gardens hold an invaluable natural and historical heritage, with their living collections providing valuable sources of information for the conservation of threatened plant species, at local and global scales.

Rediscovery of Ophiorrhiza incarnata C.E.C. Fisch. (Rubiaceae) from the Western Ghats of India after a lapse of 83 years

Ophiorrhiza incarnata C.E.C.Fisch. (Rubiaceae), a threatened plant species of southern Western Ghats is rediscovered from the adjacent area of the type locality after lapse of eight decades. Its distribution and conservation status are discussed.

Threatened Mangroves in the Anthropocene: Habitat Fragmentation in Urban Coastalscapes of Pelliciera spp. (Tetrameristaceae) in Northern South America

Mangroves are fragmented habitats thriving in human-dominated coastalscapes worldwide. They provide refuge to threatened plant species, such as the Neotropical Piñuelo Mangrove (formerly the monotypic Pelliciera genus, recently split into two species: P. rhizophorae and P. benthamii). However, little is known about the relationship between urbanization and the spatial configuration of mangrove habitat and how it would drive ecological and evolutionary changes in the small populations of Pelliciera spp. We used open data (e.g., land cover, mangrove cover) for 107 locations of Pelliciera spp. in Colombia (extant populations) to assess coastalscape structure and urbanization. We described coastalscape composition dynamics (for 2000 and 2010) and mangrove habitat configuration along a human-domination gradient, using landscape metrics. We computed an urban index to compare urbanization intensity among the study areas along the Caribbean coast and compared coastalscape structure and mangrove spatial metrics between basins (Caribbean and Pacific). The proportion of artificial surfaces was greater in the Caribbean than in the Pacific, but no temporal difference was found. The Caribbean basin exhibited a greater Urban Index, particularly in Cartagena and Urabá. Mangrove fragmentation was also greater in the Caribbean and it was influenced by the degree of urbanization. Mangrove area and core area were smaller in the Caribbean than in the Pacific, while cohesion was significantly lower in Cartagena than in other urban areas of the Caribbean. We propose a conceptual eco-evolutionary framework for linking mangrove patch reduction and isolation to demographic variables of Pelliciera spp. Edge effects are expected to affect birth and mortality rates in small patches. Small patches and small effective populations are expected to be more sensitive to novel biotic interactions, extreme weather, and gradual climate change. Isolation will also influence both emigration and immigration rates of propagules. We propose: (1) Assessing the conservation status of the two species, (2) setting monitoring programs of their populations of Pelliciera spp. and their surrounding coastalscapes (particularly in the Caribbean, (3) declaring protected areas, in wild and urban settings, to reduce mangrove fragmentation and urbanization.

Local-scale impact of wind energy farms on rare, endemic, and threatened plant species

Background Wind energy farms have become a popular solution to produce green energy worldwide. Their development within protected areas has increased dramatically in the past decade, and the effects on the rare, endemic and threatened plant species (i.e., protected plant species), essential for habitat conservation and management, are little known. Only a few studies directly quantify the impacts of wind energy farms on them. Our study analyzes the impact of wind energy farms on rare, endemic, and threatened plant species in steppic habitats and their recovery potential over a ten-year period on a wind energy farm within the Dealurile Agighiolului Natura 2000 site (Dobrogea Region, SE Romania). Methods We surveyed the rare, endemic, and threatened plant species within a radius of approximately 50 m around each of the 17 wind towers during the wind farm operational phase. We selected 34 plots to allow the investigation of two types of areas: (1) a disturbed area overlapping the technological platform, where the vegetation was removed before construction, and (2) an adjacent undisturbed area. To understand the effects of the wind energy farm on the rare, endemic, and threatened plant species diversity and the differences between the disturbed and undisturbed areas, we calculated under both conditions: (1) plant species richness; (2) sample-size-based rarefaction and extrapolation with Hill numbers parameterized by species richness; (3) non-metric multidimensional scaling of Jaccard dissimilarity index; (4) functional diversity; (5) beta-diversity (including replacement and nestedness of species). Results As a result of the disturbances caused by the wind energy farm’s development, we identified a sharp contrast between the diversity of rare, endemic, and threatened plants inhabiting disturbed and undisturbed areas near the wind towers. Our research showed that less than 40% of the total inventoried rare, endemic, and threatened species colonized the disturbed sites. Species turnover within undisturbed plots was higher than disturbed plots, implying that the plant community’s heterogeneity was high. However, a higher richness in rare, endemic, and threatened plant species was found in the plots around the wind towers in grasslands of primary type. Sample-size-based rarefaction and extrapolation with Hill numbers by observed species richness indicated an accurate estimation of species richness in disturbed habitats, demonstrating that recovery after wind energy farm construction was incomplete after ten years of low-intensity plant restoration and conservation activities. Thus, we consider that operating activities must be reconfigured to allow the complete recovery of the communities with rare, endemic, and threatened plant species.

The role of the Francisco Javier Clavijero Botanic Garden (Xalapa, Veracruz, Mexico) in the conservation of the Mexican flora

Background and Aims: There are approximately 3000 botanic gardens in the world. These institutions cultivate approximately six million plant species, representing around 100,000 taxa in cultivation. Botanic gardens make an important contribution to ex situ conservation with a high number of threatened plant species represented in their collections. To show how the Francisco Javier Clavijero Botanic Garden (JBC) contributes to the conservation of Mexican flora, we asked the following questions: 1) How is vascular plant diversity currently conserved in the JBC?, 2) How well is this garden performing with respect to the Global Strategy for Plant Conservation (GSPC) and the Mexican Strategy for Plant Conservation (MSPC)?, and 3) How has the garden’s scientific collection contributed to the creation of new knowledge (description of new plant species)?Methods: We used data from the JBC scientific living collection stored in BG-BASE. We gathered information on species names, endemism, and endangered status, according to national and international policies, and field data associated with each species. Key results: We found that 12% of the species in the JBC collection is under some risk category by international and Mexican laws. Plant families with the highest numbers of threatened species were Zamiaceae, Orchidaceae, Arecaceae, and Asparagaceae. We also found that Ostrya mexicana, Tapirira mexicana, Oreopanax capitatus, O. echinops, and O. xalapensis are highly threatened species representative of cloud forest currently in the collection. Conclusions: The conservation and scientific utility of the JBC collection is reflected in the exceptional accession data and the description of 24 new plant species. Having a significant number of threatened plant species in its ex situ collection, the JBC contributes to the implementation of the GSPC, particularly Target 8, as well as the implementation of the MSPC.

Plant nutrient acquisition strategies along an N:P gradient: implications for vegetation models

<p>Since modern days, anthropogenic activity significantly alters the nitrogen and phosphorus cycle, and these changes are substantially affecting terrestrial plant communities. Along with potassium (K), nitrogen (N) and phosphorus (P) are key nutrients limiting plant growth. Plants occupy distinct niches along N:P ratio gradients, and their physiological adaptation to these environments could potentially help us understand current and future species composition within N- and P-limited soils. Bergmann et al. (2020), provided an improved two-dimensional conceptual framework to understand resource acquisition through belowground rooting behaviour. They discerned two largely independent gradients: a conservation and a collaboration gradient. The conservation gradient differentiates between species with a slow strategy, which have a high root tissue density implying slow resource uptake and investment in long-living roots, and species with a fast strategy, that show high root N concentration implying high resource uptake but a short lifespan. The collaboration gradient goes from an outsourcing strategy with a high root diameter allowing carbon investment in fungal partners versus a do-it-yourself soil exploration strategy which requires a high specific root length. This framework, however, has not been assessed from a nutrient stoichiometric perspective. For this, we retrieved 12 belowground traits from trait databases and linked them to a European-wide field dataset of 990 vegetation recordings with species composition, site-productivity and nutrient contents of herbaceous ecosystems (extended dataset building on Wassen et al. (2021)). Using the framework of Bergmann et al. (2020), we show that plant communities in P-limited sites have adopted a slow and collaborative belowground strategy, whereas N-limited plant communities show a fast and do-it-yourself belowground strategy. Our result implies that, in addition to the benefit for fast-growing species in a nutrient-enriching world, anthropogenic alterations in the nutrient balance may also heavily affect species fitness and survival due to their nutrient-specific rooting strategies. The biggest remaining question is, however, if species will be able to adapt to changes in nutrient stoichiometry and if they can, how fast this adaptation process will be. Our results provide a new insight into belowground strategies under N or P limitation and may have consequences for the representation of plant traits in vegetation models. Finally, we strongly urge to analyse rooting traits of a larger number of species along a N:P gradient to increase the reliability of community trait estimates.</p><p> </p><p>References:</p><p>Bergmann, J., Weigelt, A., van der Plas, F., Laughlin, D. C., Kuyper, T. W., Guerrero-Ramirez, N., Valverde-Barrantes, O. J., Bruelheide, H., Freschet, G. T., Iversen, C. M., Kattge, J., McCormack, M. L., Meier, I. C., Rillig, M. C., Roumet, C., Semchenko, M., Sweeney, C. J., van Ruijven, J., York, L. M., & Mommer, L. (2020). The fungal collaboration gradient dominates the root economics space in plants.<em> Science Advances</em>, 6(27), eaba3756. https://doi.org/10.1126/sciadv.aba3756</p><p>Wassen, M. J., Schrader, J., van Dijk, J., & Eppinga, M. B. (2021). Phosphorus fertilization is eradicating the niche of northern Eurasia’s threatened plant species. <em>Nature Ecology & Evolution</em>, 5(1), 67-73. https://doi.org/10.1038/s41559-020-01323-w</p>

The Assessment and the Within-Plant Variation of the Morpho-Physiological Traits and VOCs Profile in Endemic and Rare Salvia ceratophylloides Ard. (Lamiaceae)

Salvia ceratophylloides (Ard.) is an endemic, rare, threatened plant species recently rediscovered in very few individuals in two different sites of South Italy. The study of within-plant variation more than among-plant one is fundamental to understand the plant adaptation to the local conditions, especially in rare species, and consequently to preserve plant biodiversity. Here, we reported the variation of the morpho-ecophysiological and metabolic traits between the sessile and petiolate leaf of S. ceratophylloides plants in two different sites for understanding the adaptation strategies for surviving in these habitats. The S. ceratophylloides individuals exhibited different net photosynthetic rate, maximum quantum yield, light intensity for the saturation of the photosynthetic machinery, stomatal conductance, transpiration rate, leaf area, fractal dimension and some VOCs between the different leaf types. This within-plant morpho-physiological and metabolic variation was depended on the site. These results provide empirical evidence of sharply within-plant variation of the morpho-physiological traits and VOCs profiles in S. ceratophylloides which could be because of adaptation to the local conditions.