Fraying around the edges: negative effects of the invasive Tradescantia zebrina Hort. ex Bosse (Commelinaceae) on tree regeneration in the Atlantic Forest under different competitive and environmental conditions

2019 ◽  
Vol 12 (4) ◽  
pp. 713-721
Author(s):  
Wagner A Chiba de Castro ◽  
Rafael O Xavier ◽  
Federico H L Garrido ◽  
Jair H C Romero ◽  
Cleto K Peres ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Environmental Conditions ◽  
Tree Regeneration ◽  
Negative Effects

Endoparasitism in colonial hosts: patterns and processes

Parasitology ◽  
2007 ◽  
Vol 134 (6) ◽  
pp. 841-852 ◽  
Author(s):  
S. L. L. HILL ◽  
B. OKAMURA
Keyword(s):  
Vertical Transmission ◽  
Environmental Conditions ◽  
Negative Effects ◽  
Temporal Sampling ◽  
Colony Fission ◽  
High Prevalence ◽  
Novel Host ◽  
Patterns And Processes ◽  
Host Parasite ◽  
Lack Of Knowledge

SUMMARYThis study begins to redress our lack of knowledge of the interactions between colonial hosts and their parasites by focusing on a novel host-parasite system. Investigations of freshwater bryozoan populations revealed that infection by myxozoan parasites is widespread. Covert infections were detected in all 5 populations studied and were often at high prevalence while overt infections were observed in only 1. Infections were persistent in populations subject to temporal sampling. Negative effects of infection were identified but virulence was low. Infection did not induce mortality in the environmental conditions studied. However, the production of statoblasts (dormant propagules) was greatly reduced in bryozoans with overt infections in comparison to uninfected bryozoans. Overtly-infected bryozoans also grew more slowly and had low fission rates relative to colonies lacking overt infection. Bryozoans with covert infections were smaller than uninfected bryozoans. High levels of vertical transmission were achieved through colony fission and the infection of statoblasts. Increased fission rates may be a strategy for hosts to escape from parasites but the parasite can also exploit the fragmentation of colonial hosts to gain vertical transmission and dispersal. Our study provides evidence that opportunities and constraints for host-parasite co-evolution can be highly dependent on organismal body plans and that low virulence may be associated with exploitation of colonial hosts by endoparasites.

scholarly journals Age-dependent effects of moderate differences in environmental predictability forecasted by climate change, experimental evidence from a short-lived lizard (Zootoca vivipara)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. Masó ◽  
J. Kaufmann ◽  
H. Clavero ◽  
P. S. Fitze
Keyword(s):  
Climate Change ◽  
Life History ◽  
Environmental Conditions ◽  
Life History Traits ◽  
Negative Effects ◽  
Age Classes ◽  
Environmental Predictability ◽  
Common Lizard ◽  
Zootoca Vivipara ◽  
Age Dependent

Abstract Whether and how differences in environmental predictability affect life-history traits is controversial and may depend on mean environmental conditions. Solid evidence for effects of environmental predictability are lacking and thus, the consequences of the currently observed and forecasted climate-change induced reduction of precipitation predictability are largely unknown. Here we experimentally tested whether and how changes in the predictability of precipitation affect growth, reproduction, and survival of common lizard Zootoca vivipara. Precipitation predictability affected all three age classes. While adults were able to compensate the treatment effects, yearlings and juvenile females were not able to compensate negative effects of less predictable precipitation on growth and body condition, respectively. Differences among the age-classes’ response reflect differences (among age-classes) in the sensitivity to environmental predictability. Moreover, effects of environmental predictability depended on mean environmental conditions. This indicates that integrating differences in environmental sensitivity, and changes in averages and the predictability of climatic variables will be key to understand whether species are able to cope with the current climatic change.

scholarly journals Atlantic forest bird communities provide different but not fewer functions after habitat loss

2015 ◽  
Vol 282 (1811) ◽  
pp. 20142844 ◽  
Author(s):  
Greet De Coster ◽  
Cristina Banks-Leite ◽  
Jean Paul Metzger
Keyword(s):  
Functional Diversity ◽  
Atlantic Forest ◽  
Functional Traits ◽  
Habitat Loss ◽  
Species Turnover ◽  
Bird Species ◽  
Ecological Groups ◽  
Negative Effects ◽  
Functional Integrity ◽  
New Community

Habitat loss often reduces the number of species as well as functional diversity. Dramatic effects to species composition have also been shown, but changes to functional composition have so far been poorly documented, partly owing to a lack of appropriate indices. We here develop three new community indices (i.e. functional integrity, community integrity of ecological groups and community specialization ) to investigate how habitat loss affects the diversity and composition of functional traits and species. We used data from more than 5000 individuals of 137 bird species captured in 57 sites in the Brazilian Atlantic Forest, a highly endangered biodiversity hotspot. Results indicate that habitat loss leads to a decrease in functional integrity while measures of functional diversity remain unchanged or are even positively affected. Changes to functional integrity were caused by (i) a decrease in the provisioning of some functions, and an increase in others; (ii) strong within-guild species turnover; and (iii) a replacement of specialists by generalists. Hence, communities from more deforested sites seem to provide different but not fewer functions. We show the importance of investigating changes to both diversity and composition of functional traits and species, as the effects of habitat loss on ecosystem functioning may be more complex than previously thought. Crucially, when only functional diversity is assessed, important changes to ecological functions may remain undetected and negative effects of habitat loss underestimated, thereby imperiling the application of effective conservation actions.

scholarly journals Portuguese agriculture and its role in multifunctional rural development

2010 ◽  
Vol 4 (5-6) ◽  
pp. 145-152
Author(s):  
Maria Raquel Ventura-Lucas ◽  
Carlos Marques ◽  
Maria De Belém Martins ◽  
Rui Fragoso
Keyword(s):  
Climate Change ◽  
Social Cohesion ◽  
Environmental Conditions ◽  
Rural Areas ◽  
Cultural Landscapes ◽  
Sustainable Land Management ◽  
Negative Effects ◽  
Portuguese Population ◽  
New Challenges ◽  
Safe Food

AsinEurope,agricultureinPortugalissupposedtofulfill a multiplicity of roles. It should contribute to supply Portuguese population with quality and safe food, to be viable in a global, competitive, dynamic and aggressive market, to preserve precious cultural landscapes across country through sustainable land management, to assist rural areastobeattractiveandfeasibleandtosupportemployment and social cohesion. Nevertheless, adjustments are expected to adapt to new environmental conditions, mainly climate change, to minimize weaknesses, to hold new opportunities and face new challenges. Otherwise, increases on human desertification, rural areas abandonment and consequent negative effects on territory are predictable.

scholarly journals Fauna epiedáfica associada a fragmentos florestais de Araucaria angustifolia em diferentes condições edafoclimáticas no estado do Paraná

2021 ◽  
Vol 14 (2) ◽  
pp. 1070
Author(s):  
Ketrin Lorhayne Kubiak ◽  
Jéssica Camile Da Silva ◽  
Luis Felipe Wille Zarzycki ◽  
Carlos Alberto Casali ◽  
Dinéia Tessaro
Keyword(s):  
Atlantic Forest ◽  
Environmental Conditions ◽  
Forest Fragments ◽  
Araucaria Angustifolia ◽  
Ecological Functions ◽  
Decomposition Dynamics ◽  
Southwest Region ◽  
Chemical Attributes ◽  
Dichotomous Classification ◽  
Collection Point

A fauna edáfica desempenha funções ecológicas fundamentais na interface solo-serapilheira, sendo dependente das condições ambientais que está inserida. Neste sentido, este estudo objetivou avaliar a diversidade de organismos epiedáficos em fragmentos florestais de Araucaria angustifolia na região Sudoeste do Paraná sob diferentes condições edafoclimáticas. A amostragem da fauna foi realizada em três áreas com diferentes condições edafoclimáticas, em função da variação da altitude, nos municípios de Dois Vizinhos, Pato Branco e Mangueirinha, Sudoeste do PR. Instalou-se oito armadilhas de queda em cada fragmento que permaneceram a campo por um período de sete dias. Os organismos amostrados foram identificados com auxílio de lupa binocular e chaves dicotômicas de classificação. Em cada ponto de coleta também amostrou-se o solo na camada de 0-10 cm para avaliação dos atributos químicos do solo. As diferentes condições edafoclimáticas na região Sudoeste do Paraná não afetam significativamente a abundância, riqueza e a diversidade de organismos epiedáficos associados a fragmentos florestais de Araucaria angustifolia. Porém, a temperatura interferiu na dinâmica de decomposição da matéria orgânica do solo. Epiedaphic fauna associated with Araucaria angustifolia forest fragments in different edaphoclimatic conditions in the state of Paraná A B S T R A C TThe edaphic fauna plays fundamental ecological functions in the soil-litter interface, being dependent on the environmental conditions that are inserted. In this sense, this study aimed to evaluate the diversity of epiedaphic organisms in forest fragments of Araucaria angustifolia in the Southwest region of Paraná under different edaphoclimatic conditions. The fauna sampling was carried out in three areas with different edaphoclimatic conditions, depending on the altitude variation, in the municipalities of Dois Vizinhos, Pato Branco and Mangueirinha, Southwest of PR. Eight drop traps were installed in each fragment that remained in the field for a period of seven days. The sampled organisms were identified with the aid of a binocular loupe and dichotomous classification keys. At each collection point, the soil was also sampled in the 0-10 cm layer to assess the chemical attributes of the soil. The different edaphoclimatic conditions in the Southwest region of Paraná do not significantly affect the abundance, richness and diversity of epiedaphic organisms associated with forest fragments of Araucaria angustifolia. However, the temperature interfered in the decomposition dynamics of the soil organic matter.Keywords: soil biota, Atlantic Forest, invertebrates, bioindicators

Effects of local anthropogenic stressors on a habitat cascade in an estuarine seagrass system

2019 ◽  
Vol 70 (8) ◽  
pp. 1129 ◽  
Author(s):  
Alfonso Siciliano ◽  
David R. Schiel ◽  
Mads S. Thomsen
Keyword(s):  
New Zealand ◽  
Environmental Conditions ◽  
Seagrass Beds ◽  
Associated Fauna ◽  
Negative Effects ◽  
Positive Effects ◽  
Anthropogenic Stressors ◽  
Species Change ◽  
Spatio Temporal ◽  
Primary Habitat

Recent research has shown that co-occurring primary and secondary habitat-forming species typically support higher biodiversity than do monocultures of the primary habitat-former alone. However, these ‘habitat cascades’ may not be universal and it is important to know whether, when and where positive effects on biodiversity from secondary habitat-forming species change to negative effects. Here, we tested how anthropogenic stressors (fertilisation and sedimentation) and unattached secondary habitat-forming Ulva seaweeds affected the primary habitat-forming seagrass, Zostera muelleri, and its associated invertebrates in the Avon–Heathcote Estuary, New Zealand. We experimentally stressed Zostera by adding different fertilisation and sediment levels. Fertilisation had little impact, whereas even low sedimentation levels had strong negative effects on Zostera and its associated fauna. In a second experiment, sediments and Ulva were added to seagrass beds and unvegetated mudflats to test whether sediment stress modifies habitat cascades. We found again strong negative effects of sediments on Zostera, irrespective of spatio-temporal conditions, and that negative effects of sediments on invertebrates were enhanced in the presence of the secondary habitat former. These results highlighted that anthropogenic stressors can destabilise habitat cascades; processes that may be of particular importance in estuaries that are characterised by low biodiversity and stressful environmental conditions.

Seed dormancy in tree species of the Tropical Brazilian Atlantic Forest and its relationships with seed traits and environmental conditions

2015 ◽  
Vol 38 (2) ◽  
pp. 243-264 ◽  
Author(s):  
Thaysi Ventura de Souza ◽  
Izabel Christina Torres ◽  
Neusa Steiner ◽  
Maria Terezinha Silveira Paulilo
Keyword(s):  
Atlantic Forest ◽  
Seed Dormancy ◽  
Environmental Conditions ◽  
Tree Species ◽  
Brazilian Atlantic Forest ◽  
Seed Traits

Study on Effects of Environment Conditions on Essential Service Water System of Nuclear Power Station

2017 ◽  
Author(s):  
Yang Ting ◽  
Li Guang Sheng ◽  
Li Zeng Fen ◽  
Peng Yue ◽  
Hu Jian
Keyword(s):  
Environmental Conditions ◽  
Nuclear Power ◽  
Water System ◽  
Open Water ◽  
Water Levels ◽  
Negative Effects ◽  
Power Stations ◽  
Service Water ◽  
Physical And Chemical ◽  
Essential Service

For nuclear power stations, the main function of Essential Service Water System (ESWS) is to discharge the waste heat from reactor core and spent fuel pool to the environment controllably, which is directly related to the safety and economy of nuclear power stations. Usually ESWS use open water from sea, rivers, lakes, reservoirs, as heat transfer medium. Extremely harsh environmental conditions may disable system functions and even lead to ESWS failure, directly reduce the safety and economy of nuclear power stations, and cause serious nuclear accidents. Failure of ESWS is one of the main reasons that lead to the Fukushima nuclear accident because of the loss of electricity after the earthquake and tsunami. Based on the typical ESWS configuration and conditions of serving nuclear power stations in China, the influence of environmental conditions on the function of water system is studied, and the corresponding measures are analyzed. These conditions can be divided into three categories: temperatures, water levels, and physical and chemical characteristics. Temperatures affect cooling characteristic of ESWS mainly. Nuclear power stations in tropical areas need to focus on cooling capacity might be reduced by high temperature. Those in cold region need attention to excessive cooling and freezing problems caused by low temperature. The influence of water levels is mainly fluid transport capacity and selection of equipment to ESWS. When the range of natural water level is too wide, designers shall consider measures to narrow it, such as the construction of highly reliable reservoir. Inland nuclear power stations shall try to ensure the reliability of ESWS; prevent water level changes beyond the scope of design caused by drought and flood disasters. The effects of physical and chemical properties are derived from the open water characteristics, including high salinity, high chloride ion concentration, carrying solid particles, suspended solids, and aquatics, and so on. These characteristics will cause the equipment and pipeline eroded or even damaged, aqueducts of intake and output jammed, heat exchangers of the final heat sink weakened and other negative effects, resulting in ESWS performance decline. Some of these factors are the characteristics of station site natural environment, some others are changes caused by human activities. Some factors are sustained, long-term; some others may be sudden, temporary. Influence on these factors need to be taken measures from many aspects, including structure, biological disinfection, special materials and equipment, environmental protection measures around the nuclear power station, and so on. On the whole, the environmental factors that affect ESWS in the nuclear power stations are wide, and the influence mechanism is more complex. These factors ultimately act on ESWS, but most of them cannot be banished inside of ESWS or the final heat sink system. Against the negative effects from environmental conditions, it has to be considered from all steps in the engineering of nuclear power stations, including design, construction and operation. All the measures shall be suitable to local conditions, in order to ensure the safety and economy of nuclear power stations.

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