Herbaceous Vascular Plants Research Articles

Field scale biodiversity in relation to the intensity grade of agricultural practices on dairy farms

The present study has been aimed at finding relationships, at the field level, between indicators of the intensity of agricultural practices, computed as carbon footprint (CF), nutrient balance, and intensity use of agrochemicals and indicator-species groups, selected to be representative of biodiversity, such as herbaceous vascular plants, carabid beetles (Coleoptera: Carabidae), and butterflies (Lepidoptera: Papilionoidea). Fields were selected and monitored over 2 years, on six adjacent dairy farms, to represent three cropping systems and five different intensity levels of agricultural practices: mono-cropped maize with high (M-high) or low (M-low) chemical pressure; maize in rotation (M-rot) with alfalfa (Alf) and low chemical pressure; herbaceous strips with no chemical pressure (Strip). Plants (through whole field monitoring), carabids (through pitfall traps) and butterflies (through transects) were sampled in fields and field margins; CF was computed by considering emissions linked to direct and indirect CO2, CH4 and N2O; N, P2O5 and K2O balances, as the difference between the total imported and exported nutrients, were computed at the field level; the agrochemical use intensity was assessed by frequency of application and Load indexes for non-target organisms. The CF was lower in Alf (84 kg CO2-eq/t DM) and Strip (11 kg CO2-eq/t DM) than in all the maize fields (6357, 4499, and 4059 kg CO2-eq/t DM for M-high, M-low and M-rot respectively). The highest nitrogen surplus was observed in M-high (+413 kg/ha), while it was intermediate for M-low and M-rot and the lowest in Alf. The M-high fields showed the highest load indexes for all the selected non-target organisms (mammals, fishes, algae, bees, and earthworms), whereas the lowest load indexes were observed in Strip and Alf. Overall 179 herbaceous species (20 invasive), 45 carabid species, and 39 butterfly species were observed over the 2 years study. The numbers of herbaceous species, of species of interest for pollinators, and of plant families were higher in Strip, Alf and M-rot, whereas the non-native and invasive plants were higher in M-high and Strip. The highest number of carabid species was observed in the Alf and M-low fields, and in Alf, M-low and Strip when the field margins were considered. The highest number of butterfly species was observed in M-rot, Alf and Strip when a single year was considered, whereas it was observed in Alf when the data were pooled over two years. The CF (kg CO2-eq/ha) had a marked negative effect on the plant (r = −0.90, P 0.01), carabid (r = −0.90, P 0.01) and butterfly (r = −0.79, P 0.01) species richness, as well as it positively affected the proportion of non-native invasive plants (r = 0.76, P 0.01). The N surplus negatively affected plant (r = −0.71, P 0.01) and butterfly (r = −0.81, P 0.01) species richness, while positively correlated with proportion of non-native invasive plants observed in the fields (r = 0.80, P 0.01). When all the species from the three indicator-species groups were considered together and plotted against CF (kg CO2-eq/t DM), and against N surplus (kg N/ha), great coefficients of determination were found (R2 = 0.81 and R2 = 0.88, respectively). The current findings provide evidence that well-implemented and diverse cropping systems constitute a benefit for biodiversity at the farm level, without compromising the yield potential, thus offering indications to European decision makers on how to design more specific agri-environmental measures.

Effects of stand structure and ungulates on understory vegetation in managed and unmanaged forests.

Conventional conservation policies in Europe notably rely on the passive restoration of natural forest dynamics by setting aside forest areas to preserve forest biodiversity. However, since forest reserves cover only a small proportion of the territory, conservation policies also require complementary conservation efforts in managed forests in order to achieve the biodiversity targets set up in the Convention on Biological Diversity. Conservation measures also raise the question of large herbivore management in and around set-asides, particularly regarding their impact on understory vegetation. Although many studies have separately analyzed the effects of forest management, management abandonment, and ungulate pressure on forest biodiversity, their joint effects have rarely been studied in a correlative framework. We studied 212 plots located in 15 strict forest reserves paired with adjacent managed forests in European France. We applied structural equation models to test the effects of management abandonment, stand structure, and ungulate pressure on the abundance, species richness, and diversity of herbaceous vascular plants and terricolous bryophytes. We showed that stand structure indices and plot-level browsing pressure had direct and opposite effects on herbaceous vascular plant species diversity; these effects were linked with the light tolerance of the different species groups. Increasing canopy cover had an overall negative effect on herbaceous vascular plant abundance and species diversity. The effect was two to three times greater in magnitude than the positive effects of browsing pressure on herbaceous plants diversity. On the other hand, a high stand density index had a positive effect on the species richness and diversity of bryophytes, while browsing had no effect. Forest management abandonment had few direct effects on understory plant communities, and mainly indirectly affected herbaceous vascular plant and bryophyte abundance and species richness and diversity through changes in vertical stand structure. Our results show that conservation biologists should rely on foresters and hunters to lead the preservation of understory vegetation communities in managed forests since, respectively, they manipulate stand structure and regulate ungulate pressure. Their management actions should be adapted to the taxa at stake, since bryophytes and vascular plants respond differently to stand and ungulate factors.

Exploring the biodiversity of key groups in coppice forests (Central Italy): the relationship among vascular plants, epiphytic lichens, and wood-decaying fungi

Sustainable Forest Management (SFM) indicators consider the main ecological and socioeconomic functions of forests but do not currently include some key groups widely adopted to assess the effects of forest management, such as herbaceous vascular plants, epiphytic lichens, and wood-decay fungi. Moreover, they are shaped into high forests while in the Mediterranean area the oldest type of forest management is coppice. We investigated the diversity and the relationships of the above-mentioned groups of taxa in three European Forest Types (EFTs) to contribute to the selection of indicator species suitable for monitoring Mediterranean coppice forests. We find only a weak cross-taxon congruence between vascular plants and lichens on considering the whole dataset, while no significant correlations are evident within the three EFTs. Species richness was significantly different among EFTs, being Thermophilous deciduous forests the richest, both considering the groups of taxa separately and the total species richness. As for species composition, significant differences were found both for the whole dataset and also for pairwise comparisons among EFTs. We provided a dwelling-species list of the three key groups of taxa, which could be suitable for monitoring the sustainability characteristics of fragmented and low continuity forests such as coppice stands.

Forest biomass, soil and biodiversity relationships originate from biogeographic affinity and direct ecological effects

Ecosystem biomass, soil conditions and the diversity of different taxa are often interrelated. These relationships could originate from biogeographic affinity (varying species pools) or from direct ecological effects within local communities. Disentangling regional and local causes is challenging as the former might mask the latter in natural ecosystems with varying habitat conditions. However, when the species pool contribution is considered in statistics, local ecological effects might be detected.In this study we disentangle the indirect effects of the species pool and direct ecological effects on the complex relationships among wood volume, soil conditions and diversities of different plant and fungal groups in 100 old‐growth forest sites (10 × 10 m) at the border of boreal and nemoral zones in northern Europe.We recorded all species for different vegetation groups: woody and herbaceous vascular plants, terricolous and epiphytic bryophytes and lichens. Fungal communities were detected by DNA‐based analyses from soil samples. Above‐ground wood volume was used as a proxy of biomass. We measured soil pH and nutrient content and obtained modelled climate parameters for each site. Species pool effect was considered by dividing sites into boreal and nemoral groups based on community composition. In order to disentangle direct and indirect effects, we applied variation partitioning, and raw and partial correlations.We found many significant positive relationships among studied variables. Many of these relationships were associated to boreal and nemoral species pools, thus indicating that biogeographic affinity of interacting plants and fungi largely defines forest diversity and functioning. At the same time, several relationships were significant also after considering biogeography: woody plant and ectomycorrhizal fungi diversities with wood volume, many plant and fungal groups with each other, or with soil conditions. These direct ecological interactions could be considered in forestry practices to achieve both economic gain and maintenance of biodiversity.

Vapor pressure deficit predicts epiphyte abundance across an elevational gradient in a tropical montane region.

Tropical Montane Cloud Forests (TMCFs) are important ecosystems to study and preserve because of their high biodiversity and critical roles in local and regional ecosystem processes. TMCFs may be particularly affected by changes in climate because of the narrow bands of microclimate they occupy and the vulnerability of TMCF species to projected increases in cloud base heights and drought. A comprehensive understanding of the structure and function of TMCFs is lacking and difficult to attain because of variation in topography within and across TMCF sites. This causes large differences in microclimate and forest structure at both large and small scales. In this study, we estimated the abundance of the entire epiphyte community in the canopy (bryophytes, herbaceous vascular plants, woody epiphytes, and canopy dead organic matter) in six sites. In each of the sites we installed a complete canopy weather station to link epiphyte abundance to a number of microclimatic parameters. We found significant differences in epiphyte abundance across the sites; epiphyte abundance increased with elevation and leaf wetness, but decreased as vapor pressure deficit (VPD) increased. Epiphyte abundance had the strongest relationship with VPD; there were differences in VPD that could not be explained by elevation alone. By measuring this proxy of canopy VPD, TMCF researchers will better understand differences in microclimate and plant community composition across TMCF sites. Incorporating such information in comparative studies will allow for more meaningful comparisons across TMCFs and will further conservation and management efforts in this ecosystem.

Tidal Wetland Community Response to Varying Levels of Flooding by Saline Water

A long-term data base (2000–2009) was used to evaluate tidal floodwater salinity and the resulting soil biogeochemical setting (methanogenic or sulfate reducing) at 54 substations, which included a variety of marsh and swamp community types along the freshwater/saltwater boundary of the Cape Fear River/Estuary, North Carolina. During this decade, a variety of extreme climatic events, i.e. floods and droughts, occurred, but overall data reflected long-term, natural conditions. At sites flooded by >1 ppt saline water more than 25 % of the time, wetlands consisted of varying types of tidal marsh. Temperate, tidal swamps were present at sites flooded by this level of saline water less than 12 % of high tides. Flooding >25 % of tides by >1 ppt seawater converted soils in those wetlands from methanogenic into sulfate reducing conditions >50 % of the time. The point along an estuarine gradient where adjacent wetlands are flooded by >1 ppt saline water less than 25 %, but more than 12 % is the zone of transition. The conversion of a tidal swamp to tidal marsh is not only caused by salt water itself, but by the sulfate constituent in seawater. Once a sufficient concentration of sulfate enters soils, sulfate reducing bacteria become active reducing the sulfate into hydrogen sulfide, which is toxic to any wetland plant species not adapted to this toxic substance. The incidence of flooding by high tides containing >1 ppt salinity is an accurate predictor of functional change in adjacent wetlands. Wetlands receiving intermediate levels of saline water, i.e. 12-25 % flooding with 1 ppt floodwater, were in some state of transition from swamp to marsh. Once trees in tidal swamps are killed, the wetland moves inevitably towards a tidal marsh dominated by species of herbaceous vascular plants with varying tolerance to saline water.

Fifty thousand years of Arctic vegetation and megafaunal diet

Although it is generally agreed that the Arctic flora is among the youngest and least diverse on Earth, the processes that shaped it are poorly understood. Here we present 50 thousand years (kyr) of Arctic vegetation history, derived from the first large-scale ancient DNA metabarcoding study of circumpolar plant diversity. For this interval we also explore nematode diversity as a proxy for modelling vegetation cover and soil quality, and diets of herbivorous megafaunal mammals, many of which became extinct around 10 kyr bp (before present). For much of the period investigated, Arctic vegetation consisted of dry steppe-tundra dominated by forbs (non-graminoid herbaceous vascular plants). During the Last Glacial Maximum (25-15 kyr bp), diversity declined markedly, although forbs remained dominant. Much changed after 10 kyr bp, with the appearance of moist tundra dominated by woody plants and graminoids. Our analyses indicate that both graminoids and forbs would have featured in megafaunal diets. As such, our findings question the predominance of a Late Quaternary graminoid-dominated Arctic mammoth steppe.

Natural substrata for corticioid fungi

The paper reviews the types of substrata inhabited by non-poroid resupinate Homobasidiomycetes <em>in situ</em> in global scale with both examples from literature sources and from observations on Belarus corticioid fungi biota. The groups of organic world colonized by corticioid basidiomata and vegetative mycelium are arboreous, semi-arboreous, and herbaceous vascular plants, Bryophyta, epiphytic coccoid algae, lichenized and non-lichenized fungi, and occasionally myxomycetes and invertebrates. The fungi occur on living, dying, and dead on all decay stages parts of organisms. Besides, the fungi are known on soil, humus, stones, artificial inorganic and synthetic materials and dung.

Allocating CSR plant functional types: the use of leaf economics and size traits to classify woody and herbaceous vascular plants

Summary Three main directions of adaptive specialization are evident in the world flora, reflecting fundamental trade‐offs between economics (conservative vs. acquisitive investment of resources) and size. The current method of ordinating plants according to these trade‐offs, CSR classification, cannot be applied to the woody species that dominate many terrestrial ecosystems. We aimed to produce a novel CSR classification method applicable to vascular plants in general. Principal components analysis (PCA) of variation in a range of plant traits for 678 angiosperm, gymnosperm and pteridophyte species was used to determine the limits to multivariate space occupied by functionally diverse species. From this calibration, correlations between PCA axes and values of leaf dry matter content (LDMC; as an index of conservatism in life history), specific leaf area (SLA; indicative of acquisitive economics) and leaf area (LA; photosynthetic organ size) were used to produce predictor regressions from which target species could be compared against the multivariate space. A spreadsheet was developed that returned ternary coordinates and tertiary CSR strategies for target subjects based on LA, LDMC and SLA values. The method allowed classification of target species within a triangular space corresponding to Grime's theoretical CSR triangle and was sufficiently precise to distinguish strategies between species within genera and within populations of species. It was also largely in agreement with previous methods of CSR classification for herbaceous species. Rapid CSR classification of woody and herbaceous vascular plants is now possible, potentially allowing primary plant functional types and ecosystem processes to be investigated over landscape scales.

Flora of fieId plantings and parks and its origin

The object of the studies presented in this paper was the flora of field plantings of different origin. The vascular flora ofthe plantings examined comprises 254 taxons, including 53 trees and shrubs, and 201 herbaceous vascular plants. The flora is rich and diverse. In 26,8% of taxons it is presents in all types of plantings. More than half of the registered species occurs once or twice only in all 23 planting groups studied. A detailed analysis of the flora examined shows that field plantings in agricultural landscapes may, in a small number of cases, constitute a source of weeds diaspores propagating in fields.

The Brazilian Program for Biodiversity Research (PPBio) Information System

The database of the Brazilian Program for Biodiversity Research (PPBio; GIVD ID SA-BR-001) includes data on the environment and biological groups such as plants. It is organized by site, which is usually a grid with 10 to 72 uniformly-distributed plots, and has already surveyed 1,638 releves across different Brazilian ecosystems. The sampling design is based on the RAPELD system to allow integration of data from diverse taxa and ecosystem processes. RAPELD is a spatially-explicit sampling scheme to monitor biodiversity in long-term ecological research sites and during rapid appraisals of biodiversity that has attracted support from many management agencies, which are using it as their long-term monitoring system. Vegetation surveys include measurements of cover, biomass and number of individuals from woody and herbaceous vascular plants, along with environmental data. We have recently migrated to a metadata catalog and data repository which allows searching for specific groups across all sites. All RAPELD data have been collected since 2001, though the site also allows data from other long-term plots to be archived as associated projects.

Vegetation Database of Québec (MRNF)

An ecological forest inventory was conducted from 1986 to 2000 in the portion of the Quebec province south of the 52nd parallel. The resulting database contains data from 28,425 ecological releves located throughout the different bioclimatic domains of Quebec. For each releve, information was gathered on both the vegetation composition and physical environment. Vegetation composition is described by several variables including tree species composition, floristic composition and species cover of different height strata for woody vascular plants as well as cover of herbaceous vascular plants, bryophytes and lichens. Variables describing the physical environment include altitude, slope inclination and aspect, microrelief, bedrock geology and surficial deposit, drainage, humus type, stoniness and soil texture. Data from these releves form the basic structure underlying the hierarchal ecological classification system of the Ministere des Ressources naturelles et de la Faune (MRNF). The data was also used to develop ecological classification field guides specific to each of the province’s ecological regions, providing detailed ecological knowledge to forest managers throughout the province. Finally, data from ecological releves were used to develop Canadian National Vegetation Classifications (CNVC) vegetation associations. This report describes the available content in the Vegetation Database of Quebec (MRNF) (GIVD ID NA-CA-002).

Responses of grassland species richness to local and landscape factors depend on spatial scale and habitat specialization

AbstractQuestionsTo what extent is species richness in semi‐natural grasslands related to local environmental factors and (present/past) surrounding landscape structure? Do responses of species richness depend on degree of habitat specialization (specialists vs generalists) and/or scale of the study?LocationÖland, Sweden.MethodsRichness of herbaceous vascular plants (subdivided into richness of grassland specialists and generalists) was recorded within 50 × 50 cm plots and 0.1–4.8 ha grassland polygons. Generalized linear models and hierarchical partitioning were used to identify local factors (habitat area and heterogeneity, grazing intensity, habitat continuity) and landscape factors (proportion of surrounding grassland in 2004, 1938 and 1800, and landscape diversity in 2004) associated with the richness estimates.ResultsAt the polygon scale, both specialist and generalist richness was positively associated with local habitat area and heterogeneity and, independently of area and heterogeneity, with grazing intensity, habitat continuity and amount of surrounding grassland in 1800. At the plot scale, specialist species richness was positively associated with habitat heterogeneity, amount of surrounding grassland in 2004 and landscape diversity. Plot‐scale generalist richness was negatively associated with surrounding grassland in 1938 and positively associated with local grazing intensity.ConclusionsBecause both habitat specialization and study scale influence conclusions about relationships between species richness and local and landscape factors, the study highlights the need to consider species diversity at multiple spatial scales when making decisions about grassland management. Large‐scale (polygon) species richness is influenced by immigration processes, with both specialists and generalists accumulating in old grasslands over centuries of grazing management. Habitat heterogeneity increased specialist species richness at both scales, suggesting that management policies should favour maintenance of a heterogeneous mosaic of open areas, trees and shrubs in temperate grazed grasslands. Although grassland specialists are sensitive to grassland isolation, in extensively managed landscapes with high landscape diversity input of grassland species from the landscape matrix may buffer negative effects of habitat fragmentation on grassland communities.