Grauhörnchen vs. Eichhörnchen

Competition for resources in Europe's forests – grey versus red squirrels As a result of the introduction of the north American grey squirrel in Britain, Ireland and Italy in the 19th and 20th century, the sole native tree squirrel species in Europe – the red squirrel – faced a completely novel competitor. In order to understand the interactions between the two species and to develop a conservation strategy, the two species' biology and ecology was the focus of intense research over the last 25 years. We provide an overview of research findings and the complex competitive interactions for resources and the curcial role of disease in the replacement of native red by introduced grey squirrels. Key factors in the competitive replacement process are habitat composition and patterns of seed food availability, which directly influence individual body condition and reproductive success. In addition, in the British Isles a squirrelpox virus for which grey squirrels act as a reservoir and vector has a drastic impact on the competitive interactions between the two species.     

Seevögel im Südpolarmeer

Seabirds face a number of challenges in Antarctic and Subantarctic breeding areas, such as variations in food supply and changes in the ecosystem due to climate change, aggregation and competition from the limited number of suitable breeding areas, and inaccessible breeding areas due to changes in precipitation. Adjustments to irregular food supplies, such as flexible incubation and nesting times, and torpor in chicks can help seabirds keep pace with changes occurring due to climate change. Data loggers are used to better understand the responses of adult birds to changes in the ecosystem and the resulting population trends. Various data loggers are used for a variety of applications, from one gram light loggers for long‐term tracking across large scales to high‐resolution GPS loggers with acquisition of acceleration data that can also be used to model energy expenditure. In order to fully understand the movement ecology of seabirds, several approaches need to be considered: ecological segregation in space, time and choice of food, energy landscapes and the non‐lethal effects of predation (landscapes of fear).     

Changes in Elephant Abundance Affect Forest Composition or Regeneration?

While overall numbers of African elephant have declined dramatically in recent times, some populations are now confined to protected areas and are locally overabundant—an undesirable situation for both biodiversity conservation and elephants. In forested protected areas, options to manage elephants are limited because it is difficult to safely approach animals, yet it is vital that these populations are managed because browsing by elephants can dramatically alter forest ecosystems. Using data collected over 50 yr in Kibale National Park, Uganda, we examine the prediction that increasing elephant numbers and associated changes in their foraging behavior have caused a shift in tree community composition. Although the relative abundance of elephants increased significantly between 1996 and 2010, the population structure of their preferred tree food species did not change, nor did tree community composition change in favor of species able to re‐sprout after elephant damage. Furthermore, over the last 50 yr Kibale elephants have not become more selective foragers, as would be expected if more nutritious tree species were declining. However, elephants are more abundant in disturbed areas dominated by shrubs and grasses and appear to have arrested forest succession in these areas. At their current abundance, elephants have not selectively altered the composition of intact old growth forest, but they do inhibit the regeneration of disturbed areas.     

Knöllchenbakterien: Helfer der Landwirtschaft

Knöllchenbakterium – the “microbe of the year” In 2015, the VAAM selected Knöllchenbakterium as “microbe of the year”. Knöllchenbakterium ist a collective term for a number of different bacterial species that are able to establish a root nodule symbiosis with legumes. During nodule development the bacteria differentiate into bacteroids that are confined by an additional membrane. These organelle‐like structures are now called symbiosomes, whose task is to fix molecular nitrogen for the benefit of the plant. In return, the plant has to supply all nutrients. The symbiotic interaction is initiated by a specific signal exchange. The first signals are flavonoids secreted by the plant. This leads to the activation of the bacterial nod genes. The Nod proteins synthesize and secrete Nod factors: modified and fatty acid‐carrying oligosaccharide. They serve as a specific signal to the plant and induce nodule formation. Besides this core signaling, a number of extracellular components, e.g. exopolysaccharides, lipopolysaccharides and secreted proteins influence the symbiotic interaction very specific for each individual system.     

Bio‐ und Geotop Einhornhöhle

The “Unicorn Cave” Between the towns of Herzberg and Bad Lauterberg exists an important area of Permian dolomite formations with caves and special cliffs of dolomite rock with the particular location Unicorn Cave in the centre. Even the name of this cave sounds mysterious. For hundreds of years, digging for the bones of the unicorn had been the foremost interest. The cave – home of thousands of cave‐bears – has been famous and well known even far beyond the Harz‐mountains.     

Vegetationsbrände in der Erdgeschichte

Fires in the Earth history Fire is a naturally occurring factor in the biosphere ever since the first appearance of land plants in the Late Silurian about 425 million years ago. Charcoal and characteristic polyaromatic hydrocarbons can be used as evidence for such palaeo‐wildfires. Besides the presence of fuel (=plant biomass) and sources of ignition (i.e. lightning strikes) the most important factors influencing the occurrence of fires throughout the Earth history are varying atmospheric oxygen concentrations and climatic changes. Although our knowledge about palaeo‐wildfires remains incomplete for several periods of the Earths history it is possible to use the existing knowledge to gain a better understanding of the possible impacts of current and future climate change on the fire‐ecology of modern ecosystems.     

Boden – ein unterschätzter Lebensraum

Soil – an underestimated biotope The soil is a biotope with high species abundances and richness. It is, furthermore, a location where important ecosystem services are realized. Recent research projects on the origin and development of soil animal communities, on the heterogeneous interactions within the soil nutrient net and the distribution of soil animals show the different ecological traits and adaptabilities of the world beneath our feet. So research contributes to maintain the eco‐resource of soil and its sustainable use.     

Ölpflanzen in Europa

Oil plants in Middle Europe Renewable resources have an increasing impact on industry and technology. Oil plants supply vegetable oil, which is important for our nutrition but can also be used as an industrial resource. Plant oils have many non‐food uses. They are not only used as Biofuels, but can also be found in many technical products including industrial lubricants, hydraulic oils, washing agents, paints and varnishes, and much else. In Europe rapeseed, sunflower, and olive are the primary oil plants. Rapeseed oil is newly recommended for infant nutrition, as it contains a high concentration of α‐linolenic acid, which is an important building block in brain development.     

Hormone als Schadstoffe?

Environmental estrogens Endocrine disrupters are environmental substances which interfere with the hormone system of organisms and thereby induce adverse effects. They exert their biological activity either by disrupting hormone metabolism or by imitating the biological action of the endogenous hormones. In the aquatic environment, an important group of endocrine disrupters is represented by the estrogen‐active compounds, which mimic the female sex hormone, 17β‐estradiol. Both laboratory experiments and field studies on fishes have demonstrated that already very low concentrations of environmental estrogens are able to induce disturbances in the hormone system and hormone‐regulated processes of fishes.     

Exoten am Lago Maggiore. Die Exkursion

Exotic woody plants at Lago Maggiore Insubria, the region around Lago Maggiore below about 500 m a.s.l., is characterized by mainly siliceous bedrock, acid soils and a mild climate with precipitation particularly in summer. This bioclimatic parameters together with the long history of horticulture around the lakes have led to an extraordinary diversity of woody plants in this small area of about 4.000 km². Especially the large number of evergreen broad‐leaved species, many of them introduced from warmer and subtropical parts of the world, predestines Insubria for botanical research. Some of these ornamental evergreen species have already naturalized and can be found in the insubrian deciduous forests. The article outlines also the role of woody plants during evolution.     

Informationsaustausch in der Ektomykorrhiza

To see the wood for the trees: Communication in ectomycorrhizal symbiosis The mutual symbiosis of ectomycorrhiza has been established in a co‐evolution that depends on a specific communication between the woody plant and the fungus. The exchange of inorganic nutrients and water (delivered by the fungus) for sugar (supplied by the host tree) provides the basis for the symbiosis. The interaction is initiated with signals that can be associated with root exudates and volatiles in the soil matrix. After recognition, the fungus is able to modulate plant response functions that usually suppress pathogens by excretion of effector molecules, which allows entry into the root. Within the root, specific cell wall proteins of the fungus like hydrophobins are important for host specificity. Signals in the mycorrhizal root like the auxin indole‐acetic acid modify the morphology of both partners resulting in the intimate interactions of fully established mycorrhiza. The soil hyphae of the fungus, at the same time, respond to other bacteria and fungi in the mycorrhizosphere.     

From Cassyrane to Cashmeran – The Molecular Parameters of Odorants

This review, including some new experimental results, is the summary of a talk at the ‘flavors & fragrances 2013’ conference in Leipzig, organized jointly by the GDCh, the Liebig‐Vereinigung, and the EuCheMS. After times of searching for natural odor principles and serendipitous discoveries by chemical inspiration, directed odorant design today offers the highest hit rates for the discovery of new odorants, although serendipity still plays a role. Keeping intact the electronic shape required for a certain olfactophore‐binding geometry, one can add or subtract structural elements, rigidify molecular structures, or introduce more structural flexibility. To find out which structural features are critical, the ‘seco‐approach’, in which different fragments are removed by cutting strategic bonds, is the most analytical. Following this approach, such ingredients as Serenolide, Sylkolide, and Pomarose were designed. Transferring this design principle from the family of damascones to that of the theaspiranes led to the discovery of Cassyrane, though completely different structural features turned out to be relevant. Application of the seco‐concept to a 3,7a‐substituted 2,6,7,7a‐tetrahydro‐1H‐inden‐5‐yl musk lead structure derived from carotol resulted in the discovery of a new family of dienone musks with novel structure? odor correlations. However, cutting the C(2)? O bond of Cassyrane and oxidizing the resulting seco‐structure to the 1,2,5,1″‐tetradehydro derivative links the family of dienone musks with that of blackcurrant odorants, but the resulting target structures turned out to be potent orris odorants. (3E,5E)‐5‐(tert‐Butyl)octadeca‐3,5‐dien‐2‐one even possesses the lowest odor threshold in the whole ionone family (0.036 ng/l air), which could be rationalized by a superposition analysis on (?)‐cis‐γ‐irone. In the course of the synthesis of these high‐impact orris odorants, we discovered that, depending on the reaction conditions, the dehydration step of the intermediate 5‐hydroxyalk‐3‐yn‐2‐ones was accompanied by a carbenium‐ion rearrangement. Depending on the substitution pattern, these rearrangement products and their derivatives possessed interesting musky‐woody olfactory properties reminiscent of Cashmeran, demonstrating that the same structural elements can code for completely different odors, i.e., cassis, musk, orris, violet, and Cashmeran‐type, depending only on their spatial arrangement.     

Good news from Latin America and the Caribbean: national and international restoration networks are moving ahead

Degradation of ecosystems is ongoing in Latin America but there is also a strong upswing in conservation and restoration efforts. SIACRE – the Ibero‐American and Caribbean Society for Ecological Restoration – is playing a key role in coordinating and promoting this trend at international, national, and subnational levels. In October 2014, SIACRE members organized the first national seminar on ecological restoration in Chile, with participants representing both academic and non‐academic sectors. This seminar served as the catalyst for this essay and was an historic event at the national level. Much work has been underway in the science and practice of restoration in Chile, but until now it has been fragmented. This first national seminar enabled helped the principal strengths and challenges that Chile has and must face in the transdisciplinary domain of ecological restoration. Since 2004, various meetings have been organized in the region, in order to communicate the importance of restoration, especially in Mexico, Cuba, Colombia, Brazil, and more recently in Chile and Argentina. Here we trace the history of national and subnational restoration networks in Latin America and the Caribbean, and of SIACRE, and then outline some goals and challenges for the coming years.     

Bevölkerungswachstum: Bildung ist die Lösung

Population growth – education is the answer Over the last decades world population has been constantly growing by some 80 million per year. Whereas the growth rate as well as the fertility rate have been cut by half since the 1970th, population growth will continue well over mid‐century. As the developed countries have completed the demographic transition from high mortality and fertility rates to low ones, population growth is fading out there or has already been reversed into decline. In the least developed countries mortality has fallen as well, whereas fertility decline has stalled. Therefor population growth is very high making the solution of the widespread problems in this part of the world more and more difficult. One obvious way out of this trap would be a better education that could open new development perspectives. A positive side effect is that educated women have much less offspring than their counterparts who never went to school.     

Seasonal patterns in rainforest litterfall: Detecting endogenous and environmental influences from long‐term sampling

Tropical rainforests play an important role in the storage and cycling of global terrestrial carbon. In the carbon cycle, net primary productivity of forests is linked to soil respiration through the production and decomposition of forest litter. Climate seasonality appears to influence the production of litter although there is considerable variability within and across forests that makes accurate estimates challenging. We explored the effects of climate seasonality on litterfall dynamics in a lowland humid rainforest over a 7‐year period from 2007 to 2013, including an El Niño/La Niña cycle in 2010/2011. Litterfall was sampled fortnightly in 24 traps of 0.50 m diameter within a 1‐ha forest plot. Total mean litterfall was 10.48 ± 1.32 (±SD, dry weight) Mg ha^?1 year^?1 and seasonal in distribution. The different components of litterfall were divided into L_Leaf (63.5%), L_Wood (27.7%) and L_{FF[flowers & fruit]} (8.8%), which all demonstrated seasonal dynamics. Peak falls in L_Leaf and L_Wood were highly predictable, coinciding with maximum daily temperatures and 1 and 2 months prior to maximum monthly rainfall. The El Niño/La Niña cycle coincided with elevated local winter temperatures and peak falls of L_Leaf and L_Wood. Importantly, we establish how sampling length and generalized additive models eliminate the requirement for extensive within‐site sampling when the intention is to describe dynamics in litterfall patterns. Further, a greater understanding of seasonal cycles in litterfall allows us to distinguish between endogenous controls and environmental factors, such as El Niño events, which may have significant impacts on biochemical cycles.     

Acute role of the brain-derived neurotrophic factor (BDNF) on the respiratory neural network activity in mice in vitro

In humans, several pathologies are associated with disturbances of the respiratory control, some of them including alteration in the brain-derived neurotrophic factor (BDNF) signalling pathway. BDNF has long been known as a neurotrophic factor involved in survival, differentiation and maintenance of neuronal populations in the peripheral and central nervous system. More recently BDNF has also been discovered to be a potent neuromodulator with acute effects on neuronal excitability and synaptic plasticity. Animals deleted for the gene encoding BDNF exhibit respiratory alteration suggesting an important but yet undefined role of the neurotrophin in respiratory rhythmogenesis either by a trophic and/or an acute action. The possibility that BDNF might exert an acute regulatory role on the rhythmic activity of the respiratory generator of the pre-B?tzinger complex has been recently examined in newborn mice in vitro. Results obtained, reviewed in the present paper, will help getting insights in respiratory rhythm regulatory mechanisms that involve BDNF signalling.     

Single‐Atom to Single‐Atom Grafting of Pt1 onto FeN4 Center: Pt1@FeNC Multifunctional Electrocatalyst with Significantly Enhanced Properties

Nonprecious metal catalysts (NPMCs) Fe?N?C are promising alternatives to noble metal Pt as the oxygen reduction reaction (ORR) catalysts for proton‐exchange‐membrane fuel cells. Herein, a new modulation strategy is reported to the active moiety Fe?N₄ via a precise “single‐atom to single‐atom” grafting of a Pt atom onto the Fe center through a bridging oxygen molecule, creating a new active moiety of Pt₁?O₂?Fe₁?N₄. The modulated Fe?N?C exhibits remarkably improved ORR stabilities in acidic media. Moreover, it shows unexpectedly high catalytic activities toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with overpotentials of 310 mV for OER in alkaline solution and 60 mV for HER in acidic media at a current density of 10 mA cm^?2, outperforming the benchmark RuO₂ and comparable with Pt/C(20%), respectively. The enhanced multifunctional electrocatalytic properties are associated with the newly constructed active moiety Pt₁?O₂?Fe₁?N₄, which protects Fe sites from harmful species. Density functional theory calculations reveal the synergy in the new active moiety, which promotes the proton adsorption and reduction kinetics. In addition, the grafted Pt₁?O₂? dangling bonds may boost the OER activity. This study paves a new way to improve and extend NPMCs electrocatalytic properties through a precisely single‐atom to single‐atom grafting strategy.