Abundance of arthropods as food for meadow bird chicks in response to short- and long-term soil wetting in Dutch dairy grasslands

BackgroundThroughout the world, intensive dairy farming has resulted in grasslands almost devoid of arthropods and birds. Meadow birds appear to be especially vulnerable during the chick-rearing period. So far, studies have focused mainly on describing population declines, but solutions to effectively stop these trends on the short-term are lacking. In this study at a single farm, we experimentally manipulated soil moisture through occasional irrigation, to mitigate against early season drainage and create favorable conditions for the emergence of above-ground arthropods during the meadow bird chick rearing phase.MethodsTo guarantee the presence of at least a sizeable arthropod community for the measurement of effects of wetting, we selected a farm with low intensity management. The land use and intensity of the study site and surroundings were categorized according to the national land use database and quantified using remote sensing imagery. From May 1 to June 18, 2017, we compared a control situation, with no water added, to two wetting treatments, a “short-term” (3 weeks) treatment based on wetting on warm days with a sprinkler system and a “long-term” treatment next to a water pond with a consistently raised water table from 2010. We measured soil temperature, soil moisture and resistance as well as the biomass of arthropods at 3-day intervals. Flying arthropods were sampled by sticky traps and crawling arthropods by pitfall traps. Individual arthropods were identified to Order and their length recorded, to assess their relevance to meadow bird chicks.ResultsThe land use analysis confirmed that the selected dairy farm had very low intensity management. This was different from most of the surrounding area (20 km radius), characterized by (very) high intensity land use. The experiments showed that irrigation contributed to cooler soils during midday, and that his happened already in the early part of the season; the differences with the control increased with time. In the short- and long-term treatments, soil moisture increased and soil resistance decreased from the mid-measurement period onward. Compared with the control, cumulative arthropod biomass was higher in the long-term treatment, but showed no change in the irrigation treatment. We conclude that small-scale interventions, such as occasional irrigation, favorably affected local soil properties. However, the effects on above-ground arthropod abundance currently appear limited or overridden by negative landscape-scale processes on arthropods

Mapping Agricultural Biodiversity:Legacy data and tensions between ways of seeing fields

Mapping is a core approach used to investigate and display spatial dynamics of biological diversity and habitats. In the Netherlands, agricultural lands occupy nearly two-thirds of the land surface and provide the greatest potential for habitat restoration; particularly in grassland-based dairy production systems, which comprise the largest share of these agricultural lands. When a crop rotation is applied to a long-term grassland, the resulting disruption of ecological complexity requires years–if not decades–to restore, even after reconversion. The availability of high-quality land-use data for measuring the spatio-temporal distribution of grassland legacies is thus essential for monitoring the dynamics of biodiversity in production grasslands. In this study, we reflect on the Basic Crop Registration (BRP) of the Netherlands, an open spatial data infrastructure developed for parcel-level crop registration and examine how it shapes our spatio-temporal understanding of land use. The BRP serves as an administrative basis for numerous national and local-level regulatory and financial arrangements, mainly aimed at agricultural actors. In this study, we repurposed BRP data to introduce a new perspective on depicting the stability of grasslands in a high-intensity agricultural region. We used this data to map the frequency of grassland-to-cropland conversions using 17 years of longitudinal crop records in southwest Friesland, Netherlands. The legacy effects of grassland-to-cropland conversion were investigated in a field study, where significant differences were found between new and long-term grasslands in plant community composition, soil organic matter content, bulk density, soil penetration resistance, and pH. In our analysis of BRP data, we discovered a significant number of grasslands that were recently converted from cropland but that were recorded as long-term grasslands. This affected approximately 12% of the study area from 2005–2021, which prevents the accurate tracking of grassland stability over time. This misclassification also adds uncertainty to the temporal context of the decline in grassland-dependent species in the region. However, using a spatially-explicit mapping approach, these misclassifications can be corrected and help produce an effective measure of grassland stability with potential as an agroecosystem monitoring tool for researchers, land-use planners, and policymakers

Rotation grazing as a conservation management tool:Vegetation changes after six years of application in a salt marsh ecosystem

Grazing is commonly used in conservation to promote biodiversity, but the search for a grazing management regime that optimises biodiversity is still ongoing. Rotation grazing, where grazing is followed by a relatively long period of non-grazing, is a relative new tool in conservation management, and empirical studies on its effects on biodiversity are scarce. In this study, we tested for the effects of this rotation grazing on vegetation in comparison with more traditional regimes. We used a grazing experiment on the salt marsh of Noord-Friesland Buitendijks, The Netherlands, where we determined the effect of three rotation cycles (6 years; one year summer grazing with 1 cattle ha(-1) alternated with an ungrazed year) on species richness, temporal turnover and composition in comparison with more traditional regimes of summer grazing with horses and cattle at two densities (0.5 and 1 animal ha(-1)): We also determined the change in cover of two species of specific concern, Aster tripolium (an important host plant for pollinators) and Elytrigia atherica (an invasive dominant species). After six years, species richness increased in all grazing regimes, but less in rotation than in grazing with 1 horse or 1 cattle ha(-1). Species turnover was similar across all grazing regimes. Species composition in rotation differed from compositions in 1 cattle and 1 horse ha(-1). The increase in cover of A. tripolium was lower under rotation than grazing with 0.5 cattle ha(-1), but not different to the other regimes. Change in cover of E. atherica did not significantly differ across regimes, and showed a trend of increase in the ungrazed regime only. Hence, we found that the effects of rotation grazing on vegetation are relatively similar to the grazing regimes with cattle or horses in low densities. The implementation of this rotation regime over the more traditional regimes remains to be decided by the conservation body, depending on its applicability in terms of available grazing areas and livestock, as well as overall conservation goals

Implications of landscape configuration on understory forage productivity: a remote sensing assessment of native forests openings

Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage productivity drivers in highly heterogeneous forested landscapes, or their variability over the year, are still unclear. The aim of this work is to find predictors of Normalized Difference Vegetation Index (NDVI) variation in the openings of native temperate forests and to evaluate how these predictors change within the growing season. We used high spatial resolution remote sensing imagery from NW Patagonia to separate forest openings from tree dense canopy. We obtained data of each opening related with herbaceous and shrub forage productivity and calculated landscape metrics. We estimated a multiple linear regression model for predicting NDVI in each season. Beyond known variables related with forage productivity (altitude, precipitation, etc.), the shape of forest’ openings appeared as relevant in predicting NDVI. Higher values of forest opening perimeters were related with a decrease in NDVI in spring when soil water content is not limiting and conversely with an increase in NDVI in summer when water is limiting growth. These results suggest that environmental drivers such as temperature and soil moisture inside the opening, and competition or facilitation process between trees and grasses are mediated by the shape of the opening. Management of heterogeneous native forests for cattle raising requires considering the shape of the openings to maximize forage productivity.Fil: Trinco, Fabio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Rusch, Verónica E.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Howison, Ruth A.. University of Groningen; Países BajosFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Tittonell, Pablo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentin

Small herbivores slow down species loss up to 22 years but only at early successional stage

The long-term influence of persistent small herbivores on successional plant community configuration is rarely studied. We used a herbivore exclusion experiment along the successional gradient in a salt-marsh system, to investigate the effects of hares and geese, and hares alone, on plant diversity at five successional stages (the earliest, two early, the intermediate and the late successional stages) in the short and long term, i.e. 7 and 22 years, respectively. Plant diversity declined over time at all successional stages except for the earliest one. Small herbivores slowed down species decline, but only at one early successional stage. Small herbivores slowed down species decline via decreasing dominance of preferred grass Festuca rubra in the short term, and less preferred Elytrigia atherica in the long term. The effects of hares and geese were more pronounced than hares alone, indicating an important additive role of geese, especially in the long term. Synthesis. Small herbivores can have a strong and long-lasting impact on plant diversity, but it highly depends on the abundance of small herbivores, which in turn depends on the quality and abundance of forage plants. A diverse herbivore community may have more positive effects on regulating plant communities

High Migratory Survival and Highly Variable Migratory Behavior in Black-Tailed Godwits

Few studies have been able to directly measure the seasonal survival rates of migratory species or determine how variable the timing of migration is within individuals and across populations over multiple years. As such, it remains unclear how likely migration is to affect the population dynamics of migratory species and how capable migrants may be of responding to changing environmental conditions within their lifetimes. To address these questions, we used three types of tracking devices to track individual black-tailed godwits from the nominate subspecies (Limosa limosa limosa) throughout their annual cycles for up to 5 consecutive years. We found that godwits exhibit considerable inter- and intra-individual variation in their migratory behavior across years. We also found that godwits had generally high survival rates during migration, although survival was reduced during northward flights across the Sahara Desert. These patterns differ from those observed in most other migratory species, suggesting that migration may only be truly dangerous when crossing geographic barriers that lack emergency stopover sites and that the levels of phenotypic flexibility exhibited by some populations may enable them to rapidly respond to changing environmental conditions

Warming springs and habitat alteration interact to impact timing of breeding and population dynamics in a migratory bird

In seasonal environments, increasing spring temperatures lead many taxa to advance the timing of reproduction. Species that do not may suffer lower fitness. We investigated why black-tailed godwits (Limosa limosa limosa), a ground-breeding agricultural grassland shorebird, have not advanced timing of reproduction during the last three decades in the face of climate change and human-induced habitat degradation. We used data from an 11-year field study to parameterize an Integral Projection Model to predict how spring temperature and habitat quality simultaneously influence the timing of reproduction and population dynamics. We found apparent selection for earlier laying, but not a correlation between the laying dates of parents and their offspring. Nevertheless, in warmer springs, laying dates of adults show a stronger positive correlation with laying date in previous springs than in cooler ones, and this leads us to predict a slight advance in the timing of reproduction if spring temperatures continue to increase. We also show that only in landscapes with low agricultural activity, the population can continue to act as a source. This study shows how climate change and declining habitat quality may enhance extinction risk

Planetary limits to soil degradation

Soils are essential to life on Earth but are rapidly degrading worldwide due to unsustainable human activities. We argue that soil degradation constitutes a key Earth system process that should be added to the planetary boundaries framework.info:eu-repo/semantics/publishedVersio

Large herbivores change the direction of interactions within plant communities along a salt marsh stress gradient

Question: How multiple abiotic stress factors combined with herbivory affect interactions within plant communities is poorly understood. We ask how large herbivore grazing affects the direction of plant-plant interactions along an environmental gradient in a salt marsh. Location: Grazed (cattle) and ungrazed salt marshes of the Dutch Wadden Sea island Schiermonnikoog. Here, patches of tall plant communities, dominated by the tough, unpalatable species Juncus maritimus Lam., are found alternating with low-statured, intensively grazed plant communities. Methods: Along the inundation gradient, we measured plant species composition and plant species traits (specific leaf area, specific root length, maximum height and abundance) inside and outside J. maritimus patches in grazed and ungrazed areas. In addition, we measured soil structure parameters (bulk density, soil porosity, clay depth), multiple limiting conditions for plant growth (soil salinity, soil redox, plant canopy light interception), plant biomass, presence of herbivores and abundance of soil macro-detritivores. Results: Under grazing, the palatable grasses Elytrigia atherica (Link) Kerguelen and Festuca rubra L. were positively associated with J. maritimus, while shade-intolerant Puccinellia maritima (Huds.) Parl. and Juncus gerardii Loisel. were negatively associated with this species. Furthermore, macro-detritivore presence was higher inside J. maritimus patches. In ungrazed areas E. atherica and F. rubra were negatively associated with J. maritimus, while P. maritima and J. gerardii were rare. In both grazed and ungrazed conditions the directions of species associations were independent of the inundation gradient. Analysis of species traits and abiotic conditions suggested that associational resistance (a facilitation type) was important in grazed areas. In ungrazed areas, light competition was the likely dominant process. Conclusions: The direction of species associations within these salt marsh communities was strongly affected by grazing, not by the underlying stress gradient. Measurement of species traits indicated that plant-plant interactions shifted from competitive to facilitative under grazing. Besides grazing, cross-trophic facilitation of soil disturbing macro-detritivores may play an important - thus far ignored - role in structuring plant communities

Replication Data for: Above-ground arthropod biomass responses to short- and long-term soil wetting in Dutch dairy farmland

The dataset consists of five text files: File 20170608_transect_data_QRY: data on soil temperature, moisture and resistance collected during the three surveys File landscape_context: land category classification and CSAR values used for the quantification of landscape use File pitfall2017: arthropod samples from pitfall traps File sticky2017: arthropod samples from sticky traps Temperatures: temperature data from ibuttons </ol