A field experiment to recreate species rich hay meadows using regional seed mixtures

Species rich semi-natural grasslands are an important but threatened habitat throughout Europe and much of the former area has been lost since the 1950s. However, in some countries large areas have been preserved and the demand for meadow recreation by sowing seed mixtures is increasing. In the White Carpathians Protected Landscape Area (Czech Republic) the use of commercial seed mixtures is undesirable and the use of regional mixtures has been investigated. The costs for seeding large areas are high and lower cost techniques are needed. In 1999 a field experiment was set up to investigate the establishment of hay meadow vegetation comparing sowing a regional mixture all over a plot with sowing narrow 2.5 In strips of regional seed mixtures into a matrix of a commercial grass mixture or into natural regeneration. The results after five seasons showed good establishment of the sown species in the meadow treatment. Spread of sown species from the sown strips into the surrounding matrix occurred but the cover of species was lower in the commercial grass matrix compared with the natural regeneration matrix. Colonisation of some plots by unsown desirable grassland species from adjacent grassland habitats also occurred, but more species colonised the natural regeneration matrix than the commercial grasses or the sown meadow matrix itself. Overall, the results indicate that, in appropriate situations, sown strips can provide a lower cost but slower and longer-term alternative to field scale sowing of regional seed mixtures for recreation of hay meadow vegetation. (C) 2007 Elsevier Ltd. All rights reserved.

Effects of seed addition on beetle assemblages during the re-creation of species-rich lowland hay meadows

Species-rich lowland hay meadows are of conservation importance for both plants and invertebrates; however, they have declined in area across Europe as a result of conversion to other land uses and management intensification. The re-creation of these grasslands on ex-arable land provides a valuable approach to increasing the extent and conservation value of this threatened habitat. Over a 3-year period a replicated block design was used to test whether introducing seeds promoted the re-creation of both plant and phytophagous beetle assemblages typical of a target hay meadow. Seeds were harvested from local hay meadows, and applied to experimental plots in the form of either green hay or brush harvesting seeds. Green hay spreading achieved the greatest success in re-creating plant and phytophagous beetle assemblages. While re-creation success increased over time for both taxa, for the phytophagous beetles the greatest increase in re-creation success relative to the establishment year also occurred where green hay was applied. We also considered the phytophagous beetles in terms of functional traits that describe host plant specificity, larval feeding location and dispersal. Phytophagous beetle functional trait composition was most similar to the target hay meadow assemblage where some form of seed addition was used, i.e. hay spreading or brush harvested seeds. This study identified the importance of introducing target plant species as a mechanism to promote the re-creation of phytophagous beetle communities. Seed addition methods (e.g. green hay spreading) are crucial to successful hay meadow re-creation.

Seed availability in hay meadows: Land-use intensification promotes seed rain but not the persistent seed bank

Intensification of land use in semi-natural hay meadows has resulted in a decrease in species diversity. This is often thought to be caused by the reduced establishment of plant species due to high competition for light under conditions of increased productivity. Sowing experiments in grasslands have found reliable evidence that diversity can also be constrained by seed availability, implying that processes influencing the production and persistence of seeds may be important for the functioning of ecosystems. So far, the effects of land-use intensification on the seed rain and the persistence of seeds in the soil have been unclear. We selected six pairs of extensively managed (Festuco-Brometea) and intensively managed (Arrhenatheretalia) grassland with traditional late cutting regimes across Switzerland and covering an annual productivity gradient in the range 176–1211 gm−2. In each grassland community, we estimated seed rain and seed bank using eight pooled seed-trap or topsoil samples of 89 cm2 in each of six plots representing an area of c. 150 m2. The seed traps were established in spring 2010 and collected simultaneously with soil cores after an exposure of c. three months. We applied the emergence method in a cold frame over eight months to estimate density of viable seeds. With community productivity reflecting land-use intensification, the density and species richness in the seed rain increased, while mean seed size diminished and the proportions of persistent seeds and of species with persistent seeds in the topsoil declined. Stronger limitation of seeds in extensively managed semi-natural grasslands can explain the fact that such grasslands are not always richer in species than more intensively managed ones.

Reprint of "Seed availability in hay meadows: Land-use intensification promotes seed rain but not the persistent seed bank''

Intensification of land use in semi-natural hay meadows has resulted in a decrease in species diversity. This is often thought to be caused by the reduced establishment of plant species due to high competition for light under conditions of increased productivity. Sowing experiments in grasslands have found reliable evidence that diversity can also be constrained by seed availability, implying that processes influencing the production and persistence of seeds may be important for the functioning of ecosystems. So far, the effects of land-use intensification on the seed rain and the persistence of seeds in the soil have been unclear. We selected six pairs of extensively managed (Festuco-Brometea) and intensively managed (Arrhenatheretalia) grassland with traditional late cutting regimes across Switzerland and covering an annual productivity gradient in the range 176-1211 gm(-2). In each grassland community, we estimated seed rain and seed bank using eight pooled seed-trap or topsoil samples of 89 cm(2) in each of six plots representing an area of c. 150 m(2). The seed traps were established in spring 2010 and collected simultaneously with soil cores after an exposure of c. three months. We applied the emergence method in a cold frame over eight months to estimate density of viable seeds. With community productivity reflecting land-use intensification, the density and species richness in the seed rain increased, while mean seed size diminished and the proportions of persistent seeds and of species with persistent seeds in the topsoil declined. Stronger limitation of seeds in extensively managed semi-natural grasslands can explain the fact that such grasslands are not always richer in species than more intensively managed ones. (C) 2013 Elsevier B.V. All rights reserved.

EC32-134 Sweet Clover Management

Sweet clover has made a phenomenal growth in popularity and acreage during recent years. In Nebraska, the production increased from 30,000 acres in 1920 to 1,126,000 acres in 1930, an expansion of over one million acres in a 10-year period. Just a few years ago, when sweet clover was classified as a weed, it was the subject of proposed state legislation to prevent its production and spread. Today sweet clover has a recognized place among standard crops and in rotation systems. The acreage of sweet clover in Nebraska is now practically equal to that of alfalfa and is more than ten times that of red clover. Some Nebraska counties grow more than 40,000 acres of sweet clover annually. This 1932 extension circular discusses the kinds of sweet clover; time and method of seeding; kinds of seed and rates of seeding; liming and inoculation; growth habits; utilization of sweet clover for pasture, soil building, hay and seed; and sweet clover in wild hay meadows.

Promoting Pollinating Insects in Intensive Agricultural Matrices: Field-Scale Experimental Manipulation of Hay-Meadow Mowing Regimes and Its Effects on Bees

Bees are a key component of biodiversity as they ensure a crucial ecosystem service: pollination. This ecosystem service is nowadays threatened, because bees suffer from agricultural intensification. Yet, bees rarely benefit from the measures established to promote biodiversity in farmland, such as agri-environment schemes (AES). We experimentally tested if the spatio-temporal modification of mowing regimes within extensively managed hay meadows, a widespread AES, can promote bees. We applied a randomized block design, replicated 12 times across the Swiss lowlands, that consisted of three different mowing treatments: 1) first cut not before 15 June (conventional regime for meadows within Swiss AES); 2) first cut not before 15 June, as treatment 1 but with 15% of area left uncut serving as a refuge; 3) first cut not before 15 July. Bees were collected with pan traps, twice during the vegetation season (before and after mowing). Wild bee abundance and species richness significantly increased in meadows where uncut refuges were left, in comparison to meadows without refuges: there was both an immediate (within year) and cumulative (from one year to the following) positive effect of the uncut refuge treatment. An immediate positive effect of delayed mowing was also evidenced in both wild bees and honey bees. Conventional AES could easily accommodate such a simple management prescription that promotes farmland biodiversity and is likely to enhance pollination services.

Below-ground processes in meadow soil under elevated ozone and carbon dioxide : - Greenhouse gas fluxes, N cycling and microbial communities

This thesis focuses on how elevated CO2 and/or O3 affect the below-ground processes in semi-natural vegetation, with an emphasis on greenhouse gases, N cycling and microbial communities. Meadow mesocosms mimicking lowland hay meadows in Jokioinen, SW Finland, were enclosed in open-top chambers and exposed to ambient and elevated levels of O3 (40-50 ppb) and/or CO2 (+100 ppm) for three consecutive growing season, while chamberless plots were used as chamber controls. Chemical and microbiological analyses as well as laboratory incubations of the mesocosm soils under different treatments were used to study the effects of O3 and/or CO2. Artificially constructed mesocosms were also compared with natural meadows with regards to GHG fluxes and soil characteristics. In addition to research conducted at the ecosystem level (i.e. the mesocosm study), soil microbial communities were also examined in a pot experiment with monocultures of individual species. By comparing mesocosms with similar natural plant assemblage, it was possible to demonstrate that artificial mesocosms simulated natural habitats, even though some differences were found in the CH4 oxidation rate, soil mineral N, and total C and N concentrations in the soil. After three growing seasons of fumigations, the fluxes of N2O, CH4, and CO2 were decreased in the NF+O3 treatment, and the soil NH4+-N and mineral N concentrations were lower in the NF+O3 treatment than in the NF control treatment. The mesocosm soil microbial communities were affected negatively by the NF+O3 treatment, as the total, bacterial, actinobacterial, and fungal PLFA biomasses as well as the fungal:bacterial biomass ratio decreased under elevated O3. In the pot survey, O3 decreased the total, bacterial, actinobacterial, and mycorrhizal PLFA biomasses in the bulk soil and affected the microbial community structure in the rhizosphere of L. pratensis, whereas the bulk soil and rhizosphere of the other monoculture, A. capillaris, remained unaffected by O3. Elevated CO2 caused only minor and insignificant changes in the GHG fluxes, N cycling, and the microbial community structure. In the present study, the below-ground processes were modified after three years of moderate O3 enhancement. A tentative conclusion is that a decrease in N availability may have feedback effects on plant growth and competition and affect the N cycling of the whole meadow ecosystem. Ecosystem level changes occur slowly, and multiplication of the responses might be expected in the long run.

Suomenlinnan Kustaanmiekan ketokasvillisuus ja siihen vaikuttavat tekijät

Suomenlinna on yksi Helsingin suosituimmista matkailu- ja kulttuurinähtävyyksistä. Kustaanmiekan, samoin kuin koko Suomenlinnan luonto on muodostunut perinteisestä suomalaisesta saaristoluonnosta ja vuosisatojen saatossa paikalle tulleista linnoituksien kasvistosta. Saaren vaihtelevien elinympäristöjen johdosta alueen kasvillisuus on hyvin rikasta. Linnoituksien monet kasvilajit ovat tulleet tulokaskasveina eri puolilta Eurooppaa sekä Venäjältä. Suurin osa Suomenlinnan alueesta on kallioketoa ja tämän lisäksi myös valliketoa, joista molemmat kuuluvat suojeltaviin alueisiin. Kustaanmiekan niityillä kasvaa keto- ja paahdelajeja, kuten harvinaista ketonoidanlukkoa (Botrychium lunaria L.) sekä ketoneilikkaa (Dianthus deltoides L.). Tämän tutkimuksen ensisijaisena tarkoituksena oli kartoittaa Kustaanmiekan alueen kesäkauden 2009 ketokasvilajisto ja eri putkilokasvilajien runsaus. Tutkimuksessa selvitettiin myös maaperätekijöiden ja alueen hoitohistorian mahdollista vaikutusta ketokasvilajistoon. Tutkimuksessa kartoitettiin kymmenen eri kedon kasvillisuus Suomenlinnan Kustaanmiekan linnoitusalueella. Kedot sijaitsivat eri puolilla Kustaanmiekkaa, sellaisilla paikoilla, missä ketokasvillisuus oli runsainta. Maastotyöt suoritettiin kesä- ja heinäkuussa laskemalla jokaisen kedon ruutujen putkilokasvien peittävyydet sekä listaamalla ylös myös ruutujen ulkopuoliset kevät- ja loppukesän kukkijat touko- ja elokuussa. Maaperän ominaisuuksien määrittämiseksi otettiin kultakin kedolta pintamaanäytteet elokuussa. Muita tutkittuja muuttujia olivat maapinnan kaltevuus sekä sammalen, karikkeen, paljaan maan, kenttäkasvillisuuden pohjakerros ja kallion osuus tutkimusruuduilla. Ketojen kasvillisuuden keskimääräinen korkeus mitattiin kesä- ja heinäkuussa. Kasvistossa oli selviä eroavaisuuksia ketojen välillä. Kasvilajien määrä vaihteli ketojen kokonaislajimäärän ollessa 40-60 kasvilajia. Yhteensä kedoilta löytyi 120 eri putkilokasvilajia, joista useimmat kukkivat sekä kesä- että heinäkuussa. Ketojen kasvilajimäärä vaihteli yhdellä neliömetrillä 6,3-13,6 kasvilajiin, minkä lisäksi Shannon-Wienerin diversiteetti-indeksi vaihteli 1,4-2,3 arvon välillä. Yleisimpiä lajeja, joita kedoilla tavattiin, olivat muun muassa siankärsämö (Achillea millefolium L.), koiranheinä (Dactylis glomerata L.), juolavehnä (Elymus repens L.) ja hopeahanhikki (Potentilla argentea L.). Alueella kasvoi myös muutamia sotatulokaslajeja kuten harmiota (Berteroa incana L.), ukonpalkoa (Bunias orientalis L.) ja karvahorsmaa (Epilobium hirsutum L.). Maaperätekijöillä, kuten suurella fosforin pitoisuudella ei ollut vaikutusta kasvilajien määrään kedoilla. Vain maan pH ja johtoluku korreloivat positiivisesti ketojen kasvillisuuden korkeuden kanssa. Vaikka tulosten perusteella ketojen hoidolla ei ollut vaikutusta ketojen kasvillisuuden määrään, voidaan kuitenkin olettaa oikeanlaisen hoidon parantavan tyypillisten ketokasvien kilpailukykyä muita niittykasveja kohtaan.

Replicability of data collected for empirical estimation of relative pollen productivity

The effects of repeated survey and fieldwork timing on data derived from a recently proposed standard field methodology for empirical estimation of Relative Pollen Productivity have been tested. Seasonal variations in vegetation and associated pollen assemblages were studied in three contrasting cultural habitat types; semi-natural ancient woodlands, lowland heaths, and unimproved, traditionally managed hay meadows. Results show that in woodlands and heathlands the standard method generates vegetation data with a reasonable degree of similarity throughout the field season, though in some instances additional recording of woodland canopy cover should be undertaken, and differences were greater for woodland understorey taxa than for arboreal taxa. Large differences in vegetation cover were observed over the field season in the grassland community, and matching the phenological timing of surveys within and between studies is clearly important if RPP estimates from these sites are to be comparable. Pollen assemblages from closely co-located moss polsters collected on different visits are shown to be variable in all communities, to a greater degree than can be explained by the sampling error associated with pollen counting, and further study of moss polsters as pollen traps is recommended.

Biotic resistance to plant invasion in grassland: Does seed predation increase with resident plant diversity?

Seed predation impacts heavily on plant populations and community composition in grasslands. In particular, generalist seed predators may contribute to biotic resistance, i.e. the ability of resident species in a community to reduce the success of non-indigenous plant invaders. However, little is known of predators' preferences for seeds of indigenous or non-indigenous plant species or how seed predation varies across communities. We hypothesize that seed predation does not differ between indigenous and non-indigenous plant species and that seed predation is positively related to plant species diversity in the resident community. The seed removal of 36 indigenous and non-indigenous grassland species in seven extensively or intensively managed hay meadows across Switzerland covering a species-richness gradient of 18-50 plant species per unit area (c. 2 m(2)) was studied. In mid-summer 2011, c. 24,000 seeds were exposed to predators in Petri dishes filled with sterilized soil, and the proportions of seeds removed were determined after three days' exposure. These proportions varied among species (9.2-62.5%) and hay meadows (17.8-48.6%). Seed removal was not related to seed size. Moreover, it did not differ between indigenous and non-indigenous species, suggesting that mainly generalist seed predators were active. However, seed predation was positively related to plant species richness across a gradient in the range of 18-38 species per unit area, representing common hay meadows in Switzerland. Our results suggest that generalist post-dispersal seed predation contributes to biotic resistance and may act as a filter to plant invasion by reducing the propagule pressure of non-local plant species.

Experimental evidence for the immediate impact of fertilization and irrigation upon the plant and invertebrate communities of mountain grasslands

The response of montane and subalpine hay meadow plant and arthropod communities to the application of liquid manure and aerial irrigation – two novel, rapidly spreading management practices – remains poorly understood, which hampers the formulation of best practice management recommendations for both hay production and biodiversity preservation. In these nutrient-poor mountain grasslands, a moderate management regime could enhance overall conditions for biodiversity. This study experimentally assessed, at the site scale, among low-input montane and subalpine meadows, the short-term effects (1 year) of a moderate intensification (slurry fertilization: 26.7–53.3 kg N·ha−1·year−1; irrigation with sprinklers: 20 mm·week−1; singly or combined together) on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass in the inner European Alps (Valais, SW Switzerland). Results show that (1) montane and subalpine hay meadow ecological communities respond very rapidly to an intensification of management practices; (2) on a short-term basis, a moderate intensification of very low-input hay meadows has positive effects on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass; (3) vegetation structure is likely to be the key factor limiting arthropod abundance and biomass. Our ongoing experiments will in the longer term identify which level of management intensity achieves an optimal balance between biodiversity and hay production.

Conservation of threatened habitat types under future climate change – Lessons from plant-distribution models and current extinction trends in southern Germany

A higher risk of future range losses as a result of climate change is expected to be one of the main drivers of extinction trends in vascular plants occurring in habitat types of high conservation value. Nevertheless, the impact of the climate changes of the last 60 years on the current distribution and extinction patterns of plants is still largely unclear. We applied species distribution models to study the impact of environmental variables (climate, soil conditions, land cover, topography), on the current distribution of 18 vascular plant species characteristic of three threatened habitat types in southern Germany: (i) xero-thermophilous vegetation, (ii) mesophilous mountain grasslands (mountain hay meadows and matgrass communities), and (iii) wetland habitats (bogs, fens, and wet meadows). Climate and soil variables were the most important variables affecting plant distributions at a spatial level of 10 × 10 km. Extinction trends in our study area revealed that plant species which occur in wetland habitats faced higher extinction risks than those in xero-thermophilous vegetation, with the risk for species in mesophilous mountain grasslands being intermediary. For three plant species characteristic either of mesophilous mountain grasslands or wetland habitats we showed exemplarily that extinctions from 1950 to the present day have occurred at the edge of the species’ current climatic niche, indicating that climate change has likely been the main driver of extinction. This is largely consistent with current extinction trends reported in other studies. Our study indicates that the analysis of past extinctions is an appropriate means to assess the impact of climate change on species and that vulnerability to climate change is both species- and habitat-specific.

Del barroco social a la Narrativa Salvaje en En octubre no hay milagros y "Lima, hora cero"

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

The dispersal of traditionally managed hay meadow plants via farmyard manure application

The dispersal of plants within botanically rich grassland is an important area of study if such swards are to be maintained. The application of farmyard manure provides a possible mechanism by which seeds contained within hay can be returned/introduced to grasslands. In this study, hay, dung and manure samples taken from farms with botanically rich meadows contained very limited quantities of seeds of desirable species. Digestion by cattle, and storage within a manure heap for 6 months or longer, further reduced seed germination. Samples were characterized by an abundance of the grass, Poa trivialis, with few forbs present. Confirmation of the negative effect of the digestive processes of cattle on seed viability was achieved using an in vitro laboratory experiment. However, this experiment did show that the perennial herbs, Filipendula ulmaria and Sanguisorba officinalis, were able to survive digestion at least as well as P. trivialis. The burial of known quantities of seeds in a manure heap also showed these perennial herbs to be at least as resistant to damage as P. trivialis. The results demonstrate that, given appropriate timing of the hay cut, seeds of species with high conservation value could become incorporated into manure for subsequent dispersal. However, manure dispersal would appear to be of limited value for many species desirable from a conservation viewpoint.

Efeito do Tratamento com Hidróxido de Sódio sobre a Fração Fibrosa, Digestibilidade e Tanino do Feno de Jurema-Preta (Mimosa tenuiflora. Wild)

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