Grass-clover mixtures: benefits for arable and livestock farms and biodiversity.

Introduction: Grass-clover mixtures show many benefits for sustainable agriculture. In the Netherlands, organic arable and livestock farmers often work together in a so-called partner farm concept: the arable farms grow one-year grass-clover leys to widen their crop rotation and as fodder for a livestock farm in exchange for manure. The aim of this research was to investigate the effect of different grass-clover mixtures and monocultures in a one-year ley on both aboveground and belowground parameters in light of the benefits of the ley for livestock farms, arable farms and biodiversit

De invloed van vegetatie op de erosiebestendigheid van dijken : de start van een monitoringsexperiment naar de effecten van de vegetatiesamenstelling op de erosiebestendigheid van de Purmerringdijk

Met het oog op klimaatverandering, waardoor zowel zeer droge als zeer natte perioden een grotere druk leggen op de conditie en kwaliteit van dijkgraslanden, is het zaak om experimenteel te onderzoeken welke rol de vegetatiesamenstelling heeft op de erosiebestendigheid. Door de geschiktheid van zowel gangbare als nieuwe zaadmengsels te testen en de huidige toetsingsmethoden te evalueren, kunnen de resultaten van dit onderzoek bijdragen aan toekomstige richtlijnen voor aanleg, beheer en toetsing van dijkgraslanden

Can the presence of plantain (Plantago lanceolata L.) improve nitrogen cycling of dairy grassland systems on peat soils?

Reactive nitrogen (N) losses, and in particular nitrous oxide losses, from dairy grasslands on peat soils are generally high as a result of relative high soil organic matter contents, potential N mineralisation rates and shallow groundwater levels. Effects of the inclusion of the temperate forage species plantain (Plantago lanceolata L.) (PL), which produces secondary compounds with biological nitrification inhibition capacity, on the fate of soil mineral N were studied in a combined mesocosm and field experiment. The experiments comprised four treatments differing in intentional herbage share of plantain versus perennial ryegrass (Lolium perenne L.) (100%PL, 66%PL, 33%PL and 0%PL). Potential nitrification in the mesocosm experiment was significantly lower at 100%PL versus 0%PL (p = 0.018), but soil nitrate concentrations were not. Nitrous oxide fluxes reduced by 39% (p = 0.021) in the presence of plantain in the field experiment, without an obvious link to the quantity of plantain. N use efficiency of plantain tended to increase with the quantity of plantain in the sward in the mesocosm experiment (p = 0.098), but not in the field experiment. Our results suggest that the presence of plantain can affect the fate of soil mineral N of dairy grasslands on peat soils.FWN – Publicaties zonder aanstelling Universiteit Leide

Leading trait dimensions in flood-tolerant plants

Background and AimsWhile trait-based approaches have provided critical insights in general plant functioning, we lack a comprehensive quantitative view on plant strategies in flooded conditions. Plants adapted to flooded conditions have specific traits (e.g., root porosity, low root/shoot ratio, and shoot elongation) to cope with the environmental stressors including anoxic sediments, and the subsequent presence of phytotoxic compounds. In flooded habitats, plants also respond to potential nutrient and light limitations, e.g., through the expression of leaf economics traits and size-related, respectively. However, we don’t know whether and how these trait dimensions are connected.MethodsBased on a trait dataset compiled on 131 plant species from 141 studies in flooded habitats, we quantitatively analysed how flooding-induced traits are positioned in relation to the other two dominant trait dimensions; leaf economics and size-related traits. We evaluated how these key trait components are expressed along wetness gradients, across habitat types and among plant life forms.Key ResultsWe found that flooding-induced traits constitute a trait dimension independent from leaf economics traits and size-related traits, indicating that there is no generic trade-off associated to flooding adaptations. Moreover, individual flooding-induced traits themselves are to a large extent decoupled from each other. These results suggest that adaptation to stressful environments, such as flooding, can be stressor-specific without generic adverse effects on plant functioning (e.g., causing trade-offs on leaf economics traits).ConclusionsThe trait expressions across multiple dimensions promote plant adaptations and co-existence across multi-faceted flooded environments. The decoupled trait dimensions, as related to different environmental drivers, also explain why ecosystem functioning (including e.g. methane emissions) are species- and habitat-specific. Thus, our results provide a backbone for applying trait-based approaches in wetland ecology by considering flooding-induced traits as an independent trait dimension.Environmental Biolog

Global patterns of the leaf economics spectrum in wetlands

The leaf economics spectrum (LES) describes consistent correlations among a variety of leaf traits that reflect a gradient from conservative to acquisitive plant strategies. So far, whether the LES holds in wetland plants at a global scale has been unclear. Using data on 365 wetland species from 151 studies, we find that wetland plants in general show a shift within trait space along the same common slope as observed in non-wetland plants, with lower leaf mass per area, higher leaf nitrogen and phosphorus, faster photosynthetic rates, and shorter leaf life span compared to non-wetland plants. We conclude that wetland plants tend to cluster at the acquisitive end of the LES. The presented global quantifications of the LES in wetland plants enhance our understanding of wetland plant strategies in terms of resources acquisition and allocation, and provide a stepping-stone to developing trait-based approaches for wetland ecology.Environmental Biolog

Flooding-induced adventitious rooting in Rumex : morphology and development in an ecological perspective

Contains fulltext : 6671.pdf (publisher's version ) (Open Access

Elongation by primary lateral roots and adventitious roots during conditions of hypoxia and high ethylene concentrations

Contains fulltext : 6699.pdf (publisher's version ) (Open Access