Diffuse knapweed (Centaurea diffusa) is a noxious non-native forb that is currently invading and dominating western North American grasslands. We established a series of fertilization, reverse fertilization, and removal experiments in grasslands east of the Colorado Front Range, USA, to examine the response of C. diffusa and the rest of the grassland community to changes in nutrient availabilit...

To understand the leaf-level responses of successional tree species to forest gap formation and nitrogen deposition, we performed canopy clearing and nitrogen-amendment treatments in larch plantations and investigated the changes in the light-use characteristics and the leaf structure of the invading deciduous broad-leaved tree seedlings. We hypothesized that the responses of the tree seedlings...

The effect of nitrogen deposition on the species richness of acid grasslands in Denmark: a comparison with a sudy performed on a European scale Journal Article How to cite: Damgaard, Christian; Jensen, Lennarth; Frohn, Lise Marie; Borchsenius, Finn; Nielsen, Knud Erik; Ejrnæs, Rasmus and Stevens, Carly J. (2011). The effect of nitrogen deposition on the species richness of acid grasslands in De...

Aims Aboveground biomass production commonly increases with species richness in plant biodiversity experiments. Little is known about the direct mechanisms that cause this result. We tested if by occupying different heights and depths above and below ground, and by optimizing the vertical distribution of leaf nitrogen, species in mixtures can contribute to increased resource uptake and, thus, i...

2009 2 CONTENTS 1. INTRODUCTION 9 1.1. Free radicals and their derivatives in living organisms 9 1.1.1. Reactive oxygen species (ROS) 11 1.1.2. Reactive nitrogen species (RNS) 13 1.1.3. Protective mechanisms against free radicals.

The Nannochloropsis genus contains oleaginous microalgae that have served as model systems for developing renewable biodiesel. Recent genomic and transcriptomic studies on Nannochloropsis species have provided insights into the regulation of lipid production in response to nitrogen stress. Previous studies have focused on the responses of Nannochloropsis species to short-term nitrogen stress, b...

An agroforestry experiment was conducted that involved four planting systems: monoculture of the focal species Zanthoxylum bungeanum and mixed cultures of Z. bungeanum and Capsicum annuum, Z. bungeanum and Medicago sativa and Z. bungeanum and Glycine max. Soil microbial food web (microorganisms and nematodes) was investigated under manipulated extreme rainfall in the four planting systems to as...

Cloned nitrogen fixation (nifl) genes from Klebsiella pneumoniae hybridize to DNA from 19 out of 19 widely divergent nitrogen-fixing bacterial strains but do not hybridize to DNA from 10 different non-nitrogen-fixing species. K pneumoniae nifDNA fragments that hybridize to DNA from other species contain part of the three structural genes that code for nitrogenase polypeptides. We have utilized ...

Cloned nitrogen fixation (nifl) genes from Klebsiella pneumoniae hybridize to DNA from 19 out of 19 widely divergent nitrogen-fixing bacterial strains but do not hybridize to DNA from 10 different non-nitrogen-fixing species. K pneumoniae nifDNA fragments that hybridize to DNA from other species contain part of the three structural genes that code for nitrogenase polypeptides. We have utilized ...