Context matters: the landscape matrix determines the population genetic structure of temperate forest herbs across Europe

Context Plant populations in agricultural landscapes are mostly fragmented and their functional connectivity often depends on seed and pollen dispersal by animals. However, little is known about how the interactions of seed and pollen dispersers with the agricultural matrix translate into gene flow among plant populations. Objectives We aimed to identify effects of the landscape structure on the genetic diversity within, and the genetic differentiation among, spatially isolated populations of three temperate forest herbs. We asked, whether different arable crops have different effects, and whether the orientation of linear landscape elements relative to the gene dispersal direction matters. Methods We analysed the species’ population genetic structures in seven agricultural landscapes across temperate Europe using microsatellite markers. These were modelled as a function of landscape composition and configuration, which we quantified in buffer zones around, and in rectangular landscape strips between, plant populations. Results Landscape effects were diverse and often contrasting between species, reflecting their association with different pollen- or seed dispersal vectors. Differentiating crop types rather than lumping them together yielded higher proportions of explained variation. Some linear landscape elements had both a channelling and hampering effect on gene flow, depending on their orientation. Conclusions Landscape structure is a more important determinant of the species’ population genetic structure than habitat loss and fragmentation per se. Landscape planning with the aim to enhance the functional connectivity among spatially isolated plant populations should consider that even species of the same ecological guild might show distinct responses to the landscape structure.

Sensitivity to habitat fragmentation across European landscapes in three temperate forest herbs

Context Evidence for effects of habitat loss and fragmentation on the viability of temperate forest herb populations in agricultural landscapes is so far based on population genetic studies of single species in single landscapes. However, forest herbs differ in their life histories, and landscapes have different environments, structures and histories, making generalizations difficult. Objectives We compare the response of three slow-colonizing forest herbs to habitat loss and fragmentation and set this in relation to differences in life-history traits, in particular their mating system and associated pollinators. Methods We analysed the herbs’ landscape-scale population genetic structure based on microsatellite markers from replicate forest fragments across seven European agricultural landscapes. Results All species responded to reductions in population size with a decrease in allelic richness and an increase in genetic differentiation among populations. Genetic differentiation also increased with enhanced spatial isolation. In addition, each species showed unique responses. Heterozygosity in the self-compatible Oxalis acetosella was reduced in smaller populations. The genetic diversity of Anemone nemorosa, whose main pollinators are less mobile, decreased with increasing spatial isolation, but not that of the bumblebee-pollinated Polygonatum multiflorum. Conclusions Our study indicates that habitat loss and fragmentation compromise the long-term viability of slow-colonizing forest herbs despite their ability to persist for many decades by clonal propagation. The distinct responses of the three species studied within the same landscapes confirm the need of multi-species approaches. The mobility of associated pollinators should be considered an important determinant of forest herbs’ sensitivity to habitat loss and fragmentation.

Belowground morphology and population dynamics of two forest understory herbs of contrasting growth form

Forest understory herbs exhibit a large range of variation in morphology and life history. Here we expand the reported range of variation by describing the belowground structures of two very different species, Xerophyllum tenax and Chimaphila umbellata. We excavated individuals in forests of the Cascade Mountains, Pacific Northwest, USA. Xerophyllum tenax has short rhizomes, but an extensive root system that is exceptionally large among forest understory species. The roots reach 4 m in length and may occupy an area 50 times that of the aboveground canopy. In contrast, Chimaphila umbellata has very small roots, but an extensive rhizome system. The largest plant we excavated had 57 m of connected rhizomes and still had a seedling source. Both species have long-lived individuals but differ in response to disturbance. Based on monitoring of 151 permanent 1 m2 plots in an old-growth forest, X. tenax increased only minimally in density over 40 years following tephra deposition from the 1980 eruption of Mount St. Helens, whereas density of C. umbellata increased substantially. The very different morphology of these two species highlights the large range of variation found among forest herbs, which needs to be considered when examining the forest understory.

Rapid Changes in Ground Vegetation of Mature Boreal Forests—An Analysis of Swedish National Forest Inventory Data

The boreal forest floor vegetation is critical for ecosystem functioning and an important part of forest biodiversity. Given the ongoing global change, knowledge on broad-scale changes in the composition and abundance of different plant species and species groups is hence important for both forest conservation and management. Here, we analyse permanent plot data from the National Forest Inventory (NFI) on changes in the vegetation over a 10-year period in four regions of Sweden. To limit the direct and relatively well-known effects of forest management and associated succession, we only included mature forest stands not influenced by forestry during the 10 years between inventories, and focused on vegetation change mainly related to other factors. Results show strong decrease among many species and species groups. This includes dominant species such as Vaccinimum myrtillus and Deschampsia flexuosa as well as several forest herbs. The only species increasing are some mosses in the southern regions. Our data do not allow for a causal interpretation of the observed patterns. However, the changes probably result from latent succession in combination with climate change and nitrogen deposition, and with time lags complicating the interpretation of their relative importance. Regardless of the cause, the observed changes are on a magnitude that suggest impacts on ecosystem functioning and hence highlight the need for more experimental work.

Diversity of forest herbs during summer season in the reserve forest of Bhupdeopur of district Raigarh (C.G.) India

In the present study the emphasis is given on the study of herb layer vegetation in Bhupdeopur reserve forest of Raigarh district of Chhattisgarh as the exclusive studies on herb layer in forest ecosystems are the need of present ecological time. An extensive survey has been conducted in summer to find out the various types of forest herbs. Forty four herb species were recorded in summer season , their local names and various uses by the local inhabitants including medicinal values were recorded. The parameters such as frequency , density and adundance were also undertaken.

Medicinal Plant, Anoectochilus: Distribution, Ecology, Commercial Value and Use in North Vietnam

Background: Anoectochilus orchids have been widely used as medicine. However, it has been overharvested in nature because of high commercial values. This study aims at identifying distribution ranges and ecological characteristics of Anoectochilus orchids serving for sustainable development and describing traditional uses by ethnic people in Lai Chau Province, North Vietnam. Methods: Twenty-one plots of 100 m2 each (10 m × 10 m) were established for ecological survey and stand structures were analyzed for vegetation characteristics. While interviewing was applied to gather information on harvesting method, marketing, and medicinal uses. Results: Three Anoectochilus orchids (A. lanceolatus, A. calcareus, and A. setaceus) were found in Lai Chau Province, North Vietnam. These species distribute in both evergreen old-growth and secondary broadleaved forests, and mixed broadleaf-bamboo forest on the elevations of 996–2,134 m. They grow in forests with a high canopy cover of 67 m2 canopy area/ 100 m2 land and high cover (> 90% land) of low vegetation (< 2 m tall). It is believed that using the whole plant of Anoectochilus can treat hypertension and diabetes mellitus and improve the development of underdeveloped children. The folk uses include soaking in alcohol and boiled water for daily drinks like green tea, and consuming as a vegetable. The best harvesting season is during Autumn–Winter and fresh product is mainly marketed with the price of up to 100 U$D/1 kg fresh mass. Conclusion: A. lanceolatus, A. calcareus and A. setaceus are potential forest herbs for poverty reduction to ethnic communities in North Vietnam. The natural populations have been reduced remarkably because of overharvesting. Growing techniques are an urgent need for the conservation and sustainable development of such valuable orchids.