Search results for "Climate"

Tropical Andean forests are highly susceptible to nutrient inputs--rapid effects of experimental N and P addition to an Ecuadorian montane forest.

2012

Tropical regions are facing increasing atmospheric inputs of nutrients, which will have unknown consequences for the structure and functioning of these systems. Here, we show that Neotropical montane rainforests respond rapidly to moderate additions of N (50 kg ha -1 yr -1) and P (10 kg ha -1 yr -1). Monitoring of nutrient fluxes demonstrated that the majority of added nutrients remained in the system, in either soil or vegetation. N and P additions led to not only an increase in foliar N and P concentrations, but also altered soil microbial biomass, standing fine root biomass, stem growth, and litterfall. The different effects suggest that trees are primarily limited by P, whereas some pro…

Changes in evapotranspiration and phenology as consequences of shrub removal in dry forests of central Argentina

2014

More than half of the dry woodlands (forests and shrublands) of the world are in South America, mainly in Brazil and Argentina, where in the last years intense land use changes have occurred. This study evaluated how the transition from woody-dominated to grass-dominated system affected key ecohydrological variables and biophysical processes over 20 000 ha of dry forest in central Argentina. We used a simplified surface energy balance model together with moderate-resolution imaging spectroradiometer–normalized difference vegetation index data to analyse changes in above primary productivity, phenology, actual evapotranspiration, albedo and land surface temperature for four complete growing …

Pathways towards a sustainable future envisioned by early-career conservation researchers

2021

Scientists have warned decision-makers about the severe consequences of the global environmental crisis since the 1970s. Yet ecological degradation continues and little has been done to address climate change. We investigated early-career conservation researchers' (ECR) perspectives on, and prioritization of, actions furthering sustainability. We conducted a survey (n = 67) and an interactive workshop (n = 35) for ECR attendees of the 5th European Congress of Conservation Biology (2018). Building on these data and discussions, we identified ongoing and forthcoming advances in conservation science. These include increased transdisciplinarity, science communication, advocacy in conservati…

Food availability and temperature optima shaped functional composition of chironomid assemblages during the Late Glacial–Holocene transition in North…

2021

Abstract Non-biting midges (Chironomidae) are the most diverse and abundant invertebrate group in boreal lakes and are strongly responsive to climate change, thus they are a valuable palaeoecological proxy for studying aquatic biodiversity response in the face of climate change. Here, we aim to decipher the influence of climate-induced changes on temporal patterns in chironomid assemblages. We apply a novel approach combining traditional taxon-based analysis and species-trait framework to subfossil chironomid assemblages in a sediment core covering the Late Glacial–Holocene transition in Northern Europe. We produce pollen-based July and January temperature reconstructions to characterize pa…

Biodiversity is not (and never has been) a bed of roses!

2011

9 pages; International audience; Over the last decades, the critical study of fossil diversity has led to significant advances in the knowledge of global macroevolutionary patterns of biodiversity. The deep-time history of life on Earth results from background originations and extinctions defining a steady-state, nonstationary equilibrium occasionally perturbed by biotic crises and "explosive" diversifications. More recently, a macroecological approach to the large-scale distribution of extant biodiversity offered new, stimulating perspectives on old theoretical questions and current practical problems in conservation biology. However, time and space are practically distinct, but functional…

Globacrochordiceras gen. nov. (Acrochordiceratidae, late Early Triassic) and its significance for stress-induced evolutionary jumps in ammonoid linea…

2013

<i>Globacrochordiceras transpacificum</i> gen. et sp. nov. is an ammonoid (Ammonoidea, Cephalopoda) with a shell characterized by plicate ribbing (rounded and undulating ribs strengthening on the venter without interruption), increasing involution through ontogeny, overhanging and deep umbilical wall, absence of tuberculation, subtriangular whorl section, globose adult shape with a closed umbilicus followed by an abrupt egressive coiling, and a subammonitic adult suture line. This new taxon occurs in Nevada (USA) and in Guangxi (South China). It has its typical occurrence within the <i>Neopopanoceras haugi</i> Zone of late Spathian age (Early Triassic). The plicate r…

Large herbivore population and vegetation dynamics 14,600–8300 years ago in central Latvia, northeastern Europe

2019

Abstract This study seeks to explain how the large herbivore (large vertebrate, megafauna – terrestrial taxa with adults > 45 kg) population density changed during abrupt postglacial climate and environmental change. The Lateglacial and Early Holocene (14,600–8300 years ago) were represented by various environmental and climate changes and a transition from a cold to a warm climate, with subsequent changes in flora and fauna. Using Lake Āraisi as a case study (Latvia, northeastern Europe), local to regional vegetation was reconstructed by analyzing plant macroremains and pollen from the lake sediment profile. Here, we present the first dung fungus spore-based qualitative reconstruction of l…

2020

Hypothermic Stunning in Juvenile Green Turtles (Chelonia mydas) in Uruguayan Coastal Waters: Learning for Future Events

2017

Abstract Chelonia mydas in temperate areas exhibits behavioral changes for adapting to sea temperature fluctuations; however, prolonged exposure to cold temperatures can lead to hypothermia and thus hypothermic stunning events. Here we report an unusual stranding event of 90 green turtles recorded in a 12-d period in July 2012 in southeastern Uruguay, analyzing the event in an oceanographic and meteorological context. Monitoring such events provides a unique opportunity to understand the impact of hypothermic stunning on juvenile green turtle stocks that spend the entire year in this temperate region of the southwestern Atlantic Ocean.

Towards European Dimensions of City Resilience

2016

International audience; Disaster resilience is becoming more important and raises the highest concerns worldwide, including in Europe. Cities have a vital role for resilience because a majority of the population resides in the cities. Despite the recognition of the importance of city resilience, there is no strong consensus what city resilience is and its dimensions, and how the resilience concept should be transferred into management practice in the cities. In this paper, we conduct a survey of EU sectorial approaches in terms of EU-funded projects related to climate change and critical infrastructure, where urban or city resilience are in focus. The goal is to obtain an overview of how th…