Traditional versus sprinkler irrigation of mountain hay meadows in the Valais : consequences for biodiversity

Effects of grassland management on plants and invertebrates in Transylvania, Romania : a threat to local biodiversity hotspots

Effects of different irrigation systems on the biodiversity of species-rich hay meadows

QuestionsDoes the recent change from traditional to sprinkler irrigation result in alterations in the surrounding landscape of species‐rich hay meadows in an arid Swiss mountain region? Are landscape composition and landscape heterogeneity important determinants of plant diversity in these meadows?LocationSouthwestern Switzerland.MethodsWe surveyed vascular plant species in six traditionally and six sprinkler‐irrigated hay meadows. Plant species were divided into grassland specialists and generalists. Individual landscape traits were assessed in circular areas with radii of 50 and 100 m around each meadow in a field survey. Aerial photographs were used to measure the percentage area covered by different habitat types in the present and prior to the installation of sprinklers at the same spatial scale as in the field surveys. The potential effects of irrigation technique and present‐day landscape features on the plant diversity and species composition of hay meadows were examined with GLM and NMDS.ResultsLandscape composition was more diverse for traditionally than for sprinkler‐irrigated meadows, but did not differ prior to the installation of sprinklers. Total plant species richness and the number of specialists were negatively affected by the distance to the closest haystack. Generalists were positively influenced by a variety of different small‐scale landscape traits in the surroundings, whereas the percentage area covered by woodland had a negative effect. Finally, hay meadows irrigated with sprinklers had an increased number of generalist plant species.ConclusionsThis study showed that the small‐scale surroundings, and to some extent the type of irrigation, are important for the conservation of plant diversity of these meadows. Furthermore, the study suggests that the installation of sprinklers was associated with a homogenization of the landscape, which facilitates land use. Extensive management should be promoted by compensation payments for farmers to prevent intensification.

Traditional management practices are suggested to maintain species-rich grasslands. In the Valais, an arid region of Switzerland, hay meadows are traditionally irrigated using open water channels. However, in the past decades this irrigation technique has been increasingly replaced by sprinkler irrigation, which is assumed to result in a more homogeneous water distribution than open water channels. This study examined whether the change in irrigation technique affected the small-scale distribution of plants and soil characteristics in hay meadows in the Valais. Three plots consisting of 13 subplots of increasing size (0.1 × 0.1 to 6.4 × 6.4 m) were installed in six traditionally and six sprinkler-irrigated meadows. In all subplots, plant species richness and soil characteristics [moisture, pH, total organic nitrogen, organic matter content (SOM), total and plant available phosphorus] were recorded. The type of irrigation technique did not affect the shape of the plant species–area relationship. In none of the meadows did the species area–curves reach the asymptote within the range of plot sizes examined. Mantel r statistics showed that spatial autocorrelation in the soil characteristics examined was low and their small-scale distributions were not influenced by the irrigation technique except for soil pH and SOM. Our results indicate a pronounced small-scale heterogeneity in the distribution of plant species and soil characteristics for both types of irrigation technique. This can partly be explained by the fact that sprinklers distribute the water less homogeneously than commonly assumed. As applied in the Valais, sprinkler irrigation does not reduce the spatial heterogeneity and hence biodiversity of hay meadows.

Plant species richness of permanent grasslands has often been found to be significantly associated with productivity. Concentrations of nutrients in biomass can give further insight into these productivity- plant species richness relationships, e.g. by reflecting land use or soil characteristics. However, the consistency of such relationships across different regions has rarely been taken into account, which might significantly compromise our potential for generalization. We recorded plant species richness and measured above-ground biomass and concentrations of nutrients in biomass in 295 grasslands in three regions in Germany that differ in soil and climatic conditions. Structural equation modelling revealed that nutrient concentrations were mostly indirectly associated with plant species richness via biomass production. However, negative associations between the concentrations of different nutrients and biomass and plant species richness differed considerably among regions. While in two regions, more than 40% of the variation in plant species richness could be attributed to variation in biomass, K, P, and to some degree also N concentrations, in the third region only 15% of the variation could be explained in this way. Generally, highest plant species richness was recorded in grasslands where N and P were co-limiting plant growth, in contrast to N or K (co-) limitation. But again, this pattern was not recorded in the third region. While for two regions land-use intensity and especially the application of fertilizers are suggested to be the main drivers causing the observed negative associations with productivity, in the third region the little variance accounted for, low species richness and weak relationships implied that former intensive grassland management, ongoing mineralization of peat and fluctuating water levels in fen grasslands have overruled effects of current land-use intensity and productivity. Finally, we conclude that regional replication is of major importance for studies seeking general insights into productivity-diversity relationships.

There is a wealth of smaller-scale studies on the effects of forest management on plant diversity. However, studies comparing plant species diversity in forests with different management types and intensity, extending over different regions and forest stages, and including detailed information on site conditions are missing. We studied vascular plants on 1500 20m×20m forest plots in three regions of Germany (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin). In all regions, our study plots comprised different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests, which resulted from clear cutting or shelterwood logging), various stand ages, site conditions, and levels of management-related disturbances. We analyzed how overall richness and richness of different plant functional groups (trees, shrubs, herbs, herbaceous species typically growing in forests and herbaceous light-demanding species) responded to the different management types. On average, plant species richness was 13% higher in age-class than in unmanaged forests, and did not differ between deciduous age-class and selection forests. In age-class forests of the Schwäbische Alb and Hainich-Dün, coniferous stands had higher species richness than deciduous stands. Among age-class forests, older stands with large quantities of standing biomass were slightly poorer in shrub and light-demanding herb species than younger stands. Among deciduous forests, the richness of herbaceous forest species was generally lower in unmanaged than in managed forests, and it was even 20% lower in unmanaged than in selection forests in Hainich-Dün. Overall, these findings show that disturbances by management generally increase plant species richness. This suggests that total plant species richness is not suited as an indicator for the conservation status of forests, but rather indicates disturbances.

1. The consequences of species loss on ecosystem functioning within a single trophic level have been extensively studied. However, the loss of basal species is likely to have profound impacts on the abundance, richness and ecosystem functioning of species at higher trophic levels. 2. Here, we used experimentally established plant communities with a species richness gradient to study the effects of plant species loss on a multi-trophic insect community in the field. We measured densities and species richness of aphids and parasitic wasps (primary, secondary and facultative tertiary parasitoids of aphids) that naturally colonized the grassland plots. 3. Furthermore, we calculated two ecosystem functions: aphid load (the number of aphid individuals per host plant biomass used as a proxy for herbivory) and parasitism rate. We used structural equation models to explore pathways of direct and indirect effects of plant species richness on higher trophic levels. 4. We found that the densities and richness of species at all trophic levels were influenced by changes in plant species richness. The effects were rarely direct, but instead mediated by the abundance and species richness of aphid host plants and subsequent trophic levels. 5. The herbivore and primary parasitoid levels were most directly affected by changes in plant species richness, with highest insect densities and species richness occurring at intermediate plant species richness. The densities and species richness of secondary parasitoids declined linearly with plant species richness owing to sparser resources, resulting in shorter food chains in communities with the highest plant species richness. 6. Aphid load was highest at intermediate plant species richness and negatively affected by both host plant biomass and host plant species richness. Parasitism rate was mostly affected indirectly via aphid density and overall only weakly negatively related to plant species richness. 7. Our results demonstrate that plant species richness can have strong cascading effects up to high trophic levels. However, their direction may differ at the lower and higher ends of the plant species richness spectrum, cautioning against simplifying consequences of plant species loss for specialist food webs that may become limited by sparse resources at high plant richness.

Summary A field experiment was carried out over 2005–2006 at Kruszyn Krajenski near Bydgoszcz. The experiment was established as twofactorial including: I – sprinkling irrigation: K – without sprinkling irrigation (control), W – sprinkling irrigation, II: varied nitrogen fertilization: N0 = 0 kg N/ha, N1 = 40 kg N/ha, N2 = 80 kg N/ha, N3 = 120 kg N/ha. The subject of this study were insects which were caught successively with an entomological net three times during the growing seasons, in July and August. In each of three replications of the treatment with an area of 10 m 2 , five sweeps were made. It was found that the irrigated plants of buckwheat cultivar Panda were more attractive for Hemiptera and Thysanoptera in comparison to non-irrigated. The most numerous Hemiptera on buckwheat plants were Miridae, which preferred irrigated plants and a high rate of nitrogen fertilization. Cicadellidae: Psammotettix alienus, Macrosteles laevis and Empoasca pteridis occurred in a greater number on non-irrigated plants and with high nitrogen rate. Thysanoptera were less frequent than Hemiptera. The most numerous Thysanoptera on buckwheat plants were Phlaeothripidae which preferred irrigated plants and medium rate of nitrogen fertilization.

Contrasting effects of irrigation and fertilization on plant diversity in hay meadows

We analyzed the consequences of climate change and the increase in soil erosion, as well as their interaction on plant and soil properties in semiarid Mediterranean shrublands in Eastern Spain. Current models on drivers of biodiversity change predict an additive or synergistic interaction between drivers that will increase the negative effects of each one. We used a climatic gradient that reproduces the predicted climate changes in temperature and precipitation for the next 40 years of the wettest and coldest end of the gradient; we also compared flat areas with 20° steep hillslopes. We found that plant species richness and plant cover are negatively affected by climate change and soil erosion, which in turn negatively affects soil resistance to erosion, nutrient content and water holding capacity. We also found that plant species diversity correlates weakly with plant cover but strongly with soil properties related to fertility, water holding capacity and resistance to erosion. Conversely, these soil properties correlate weaker with plant species cover. The joint effect of climate change and soil erosion on plant species richness and soil characteristics is antagonistic. That is, the absolute magnitude of change is smaller than the sum of both effects. However, there is no interaction between climate change and soil erosion on plant cover and their effects fit the additive model. The differences in the interaction model between plant cover and species richness supports the view that several soil properties are more linked to the effect that particular plant species have on soil processes than to the quantity and quality of the plant cover and biomass they support. Our findings suggest that plant species richness is a better indicator than plant cover of ecosystems services related with soil development and protection to erosion in semiarid Mediterranean climates.

During the present time, the coastal area is lack of interested by the farmer as the cultivation site of agriculture plant. It is caused by the problem constraint of land physical character and the climate (particularly, micro climate), so that most confined the kinds of plant may be cultivated. The more narrowed of agriculture area, then optimalizing the use of coastal area for developing agriculture is necessary to conduct, although must throungh various means with an environment reengineering, as climate modification, conservation efforts of land moisture, supplying irrigation water, and etc. So that in the research will be implemented the research on the melon plant cultivation with various treatment.But, these condition of micro climate can be manipulated or reengineered with using simple technology in shape of closed shade, so that can be created an ideal condition for cultivation requirements. The result show that melon plant cultivated under the shade with sprinkler irrigation and drip irrigation gives the highest result that is 325 kg/70 m2 or 4,65 kg/m2, the melon planted under the shade + sprinkler irrigation + mulse the result 272 kg/70 m2 or 3,89 kg/m2, while the lowest result is that planted without using the shade with sprinkler irrigation and drip irrigation : 200 kg/m2 or 2,86 kg/m2.

The massive declines in terrestrial arthropods reported across Europe call for effective methods to monitor and promote biodiversity in human-dominated landscapes. Previous studies vary in their support for the suitability of plants as indicators of arthropod diversity, while the potential of subsets of conservation-relevant plant species to estimate arthropod richness remains to be tested. Moreover, the relative importance of plant species richness compared to other factors driving arthropod richness, such as land-use intensity, habitat amount and landscape configuration, is poorly understood. We conducted a multi-scale field study in Southern Germany, sampling vascular plants and terrestrial arthropods in four local land-use types (forest, grassland, arable field, settlement) across large-scale gradients of climate and land-use intensity. We obtained an extensive arthropod dataset using Malaise traps as sampling method and DNA metabarcoding for species identification. We compared the correlation of three sets of plant species richness (total, red-listed and biotope-indicator plants) with arthropod richness, including different trophic and taxonomic groups. Using mixed-effect models, we assessed the partial effects of plant species richness, habitat amount and landscape configuration on local arthropod richness while controlling for climate and land-use effects, and explored the environmental drivers of plant species richness. Arthropod species numbers of all trophic groups strongly responded to species numbers of plants that indicate protected habitats, while red-listed plant species richness was a key determinant for the richness of red-listed arthropods and butterflies. In most cases, plant species richness and temperature were stronger drivers of arthropod richness than the amount of surrounding semi-natural habitat and landscape configuration. While total plant species richness was highest in settlements, the richness of biotope-indicator plants was highest in forests and positively influenced by the amount of semi-natural habitat and edge density. The number of red-listed plant species increased with edge density at the landscape scale but was independent of habitat amount. We conclude that the richness of conservation-relevant plant species provides a powerful indicator of arthropod diversity, and underpins the potential of such plant lists for monitoring habitat quality. Our study highlights the importance of openings in forests for conservation of plants and arthropods as well as of preserving and restoring fragments of high-quality biotopes in agricultural and urban areas where the amount of semi-natural habitat is limited.

Arbuscular mycorrhiza is an ancient symbiosis between the majority of land plants and fungi
\nfrom the phylum Glomeromycota. Arbuscular mycorrhizal fungi (AMF) colonize plant roots
\nand contribute to the mineral nutrient uptake of the hosts in exchange for carbohydrates. AMF
\nspecies diversity and identity was reported to have a decisive influence on the composition
\nand productivity of natural plant communities. Only around 200 glomeromycotan species
\ndescribed so far were thought to colonize the majority of higher plant species and thus, their
\nhost specificity was thought to be very low.
\nIn this thesis, molecular methods were used to investigate ecological aspects of root
\ncolonizing AMF. The community composition of these fungi was analyzed in two plant
\nspecies-rich grasslands facing different environmental conditions and harboring different
\nplant communities. One site consisting of two meadows located close to each other was
\nsituated in the upper montane zone of the Swiss Alps. The other was located in the lowland in
\nFrance on the edge of the Jura mountains. The roots were analyzed using AMF-specific
\nnested PCR, RFLP screening and sequencing of rDNA small subunit and internal transcribed
\nspacer regions. AMF sequences were analyzed phylogenetically and used to define
\nmonophyletic sequence types.
\nOverall, 27 different AMF sequence types were detected in the root samples from both
\nfield sites. The overlap between the AMF communities in the alpine and lowland site was
\nrelatively small - they shared just six sequence types. These results indicate strong
\ngeographical differences in the AMF community composition, reflecting different
\nenvironmental conditions and plant species communities in each site.
\nThe question was adressed, whether different host plant species co-occurring in the same
\narea host distinct or similar AMF communities. Gentiana verna, G. acaulis and Trifolium spp.
\ngrowing in two alpine species-rich meadows harbored significantly different AMF
\ncommunities, whereas the differences between the two sites were negligible. These results
\nindicate that within a relatively small area with similar soil and climatic conditions, the host
\nplant species can have a major influence on the AMF communities within the roots. In these
\nalpine sites, there was also a focus on green plants from the family Gentianaceae. In contrast
\nto their mycoheterotrophic relatives, the green gentians did not show a high level of
\nspecificity towards AMF. The plants sampled harbored AMF communities comprising
\nmultiple phylotypes from different fungal lineages.
\nIn the lowland site – a calcareous grassland – different culturing methods and their
\ninfluence on the AMF community composition in the roots were adressed. Four plant species
\nwere sampled i) directly in the field, ii) in a bait plant bioassay conducted directly in that
\n
\ngrassland and iii) in a greenhouse trap experiment using soil and a transplanted whole plant
\nfrom that grassland as inoculum. The community composition in their roots was strongly
\ninfluenced by the experimental approach, with additional influence of cultivation duration,
\nsubstrate and host plant species in some experiments.
\nSome fungal phylotypes, e.g. Glomus mosseae and several members of Glomus group B,
\nappeared predominantly in the greenhouse experiment or in bait plants. These phylotypes can
\nbe considered r strategists, rapidly colonizing uncolonized ruderal habitats in early
\nsuccessional stages of the fungal community. Other phylotypes as Glomus badium and
\nGLOM-A16 were detected almost exclusively in roots sampled from plants naturally growing
\nin the grassland or from bait plants exposed in the field, indicating that they preferentially
\noccur in late successional stages of fungal communities and thus represent the K strategy. The
\nonly phylotype found with high frequency in all three experimental approaches as well as in
\nthe alpine site was GLOM A-1 (Glomus intraradices), which is assumed to be a generalist.
\nThese ecological strategies of different AMF species or phylotypes should be considered
\nin AMF experimental work. In greenhouse trap experiments it is difficult to establish a rootcolonizing
\nAMF community reflecting the diversity of these fungi in the field roots, because
\nfungal succession in such artificial systems may bias the results. However, the field bait plant
\napproach might be a convenient way to study the influence of different environmental factors
\non AMF community composition directly under the field conditions.
\nFinally, the co-existence of the Glomeromycota in the root samples with fungi from the
\nbasidiomycotan order Sebacinales was addressed. These fungi are widely distributed and
\nknown to form various types of presumable mycorrhizal associations of different morphology
\n(ecto-, ectendo-, orchid, ericoid, jungermannoid) with a broad range of host plant species.
\nHowever, their presence in plants forming arbuscular mycorrhiza has not been reported yet.
\nTherefore, the root samples originating from the two species-rich grasslands mentioned above
\nwere analyzed with Sebacinales-specific primers for the D1/D2 region of the nuclear 28S
\nrDNA subunit. Fungi from the order Sebacinales were present in the majority of the root
\nsamples from both sites, where they co-existed with the Glomeromycota. In agreement with
\nstudies targeting the Sebacinales in ericoid plants, the phylogenetic analysis of sebacinoid
\nsequences from our samples did not reveal any patterns according to their host plant species
\nor geographical origin.

Improvement of agricultural water management by implementing more efficient irrigation methods is essential for sustainable use of water and soil resources. The main objective was to assess and compare the use of parametric evaluation (PM) and multi‐criteria assessment (MCA) in the decision and planning process of irrigation management by land suitability assessment of three irrigation techniques. Land and soil properties were determined and assessed, and suitability maps were produced for surface, sprinkler and drip irrigation methods in the Çarşamba Delta plain (Black Sea region, Turkey; 972.2 ha). MCA was more flexible and sensitive due to the analytical hierarchy process and thus better reflected real conditions, than the widely used PM. In both approaches, drip irrigation was the most suitable. The main restricting factors in all irrigation systems in this area were slope, soil depth and soil texture. Results demonstrated that the arability of 33% (PM) or 30% (MCA) of the study area would be improved by employing drip irrigation instead of surface or sprinkler irrigation. Maps show where the change of traditional surface irrigation system should start. Such a change would be projected into better water use efficiency and more efficient use of soil while reducing degradation processes, namely soil erosion. © 2019 John Wiley & Sons, Ltd.

The availability of floral resources is considered a key factor for the maintenance and conservation of pollinators. We compared the forage floral diversity of three types of lowland meadows (Molinia meadows, tall herb fringe meadows, and hay meadows) located in south eastern Poland. The total number of plant species was 125, including 84 species (67.2%) classified as plants visited by insects. The richness and diversity of forage flora differed between the types of meadow. The Molinia meadows and hay meadows were preferred by pollinators. However, different taxonomic groups of pollinators can respond to the variability and availability of floral resources in a different way. Molinia meadows are of particular importance for the abundance of Bombus spp., solitary bees, and flies. The RDA ordination model demonstrated that the floral community composition, plant species abundance, plant species richness, and floral attributes (size, shape, phenology) were all important for the abundance of insect visitors in the mosaic of meadows. The cluster analysis showed that most plant species were visited by similar groups of insects; however, their proportion differed considerably. Our results present arguments for inclusion of semi-natural meadows into conservation plans and for efforts of protection of highly effective floral resources aimed at maintenance of pollinators.