scholarly journals Climate change, climatic variation and extreme biological responses

2017 ◽  
Vol 372 (1723) ◽  
pp. 20160144 ◽  
Author(s):  
Georgina Palmer ◽  
Philip J. Platts ◽  
Tom Brereton ◽  
Jason W. Chapman ◽  
Calvin Dytham ◽  
...  
Keyword(s):  
Climatic Variability ◽  
Population Trends ◽  
Population Changes ◽  
Widespread Species ◽  
Population Responses ◽  
Extreme Climatic Events ◽  
Biological Responses ◽  
Biodiversity Change ◽  
Taxonomic Groups

Extreme climatic events could be major drivers of biodiversity change, but it is unclear whether extreme biological changes are (i) individualistic (species- or group-specific), (ii) commonly associated with unusual climatic events and/or (iii) important determinants of long-term population trends. Using population time series for 238 widespread species (207 Lepidoptera and 31 birds) in England since 1968, we found that population ‘crashes’ (outliers in terms of species' year-to-year population changes) were 46% more frequent than population ‘explosions’. (i) Every year, at least three species experienced extreme changes in population size, and in 41 of the 44 years considered, some species experienced population crashes while others simultaneously experienced population explosions. This suggests that, even within the same broad taxonomic groups, species are exhibiting individualistic dynamics, most probably driven by their responses to different, short-term events associated with climatic variability. (ii) Six out of 44 years showed a significant excess of species experiencing extreme population changes (5 years for Lepidoptera, 1 for birds). These ‘consensus years’ were associated with climatically extreme years, consistent with a link between extreme population responses and climatic variability, although not all climatically extreme years generated excess numbers of extreme population responses. (iii) Links between extreme population changes and long-term population trends were absent in Lepidoptera and modest (but significant) in birds. We conclude that extreme biological responses are individualistic, in the sense that the extreme population changes of most species are taking place in different years, and that long-term trends of widespread species have not, to date, been dominated by these extreme changes. This article is part of the themed issue ‘Behavioural, ecological and evolutionary responses to extreme climatic events’.

Seeing the wood and the trees—predicting the future for fragmented plant populations in Australian landscapes

2007 ◽  
Vol 55 (3) ◽  
pp. 250 ◽  
Author(s):  
Linda Broadhurst ◽  
Andrew Young
Keyword(s):  
Rare Species ◽  
Reproductive Strategy ◽  
Plant Populations ◽  
Widespread Species ◽  
Current State ◽  
Considerable Research ◽  
Demographic Processes ◽  
New Challenges ◽  
Taxonomic Groups

Australian landscapes face significant environmental challenges in the coming decade. The fragmentation of vegetation following broadscale land-clearing has rapidly altered critical genetic and demographic processes within and among the remnants that still reside in these landscapes. These perturbations threaten the long-term persistence of many species. Although considerable research has been directed towards the management of rare species, little is understood about how common and widespread species respond to these new challenges. In this paper we review the current state of knowledge regarding species biology for some key Australian taxonomic groups to develop broad predictions about the major threats to species persistence, particularly for some of the most common and widespread floral components of fragmented Australian landscapes. The main focus is on associations between reproductive strategy, vulnerability to demographic and genetic threats, and implications for fecundity.

scholarly journals Effect of ecological and conventional managements on soil enzymatic activities in coffee agroecosystems

2018 ◽  
Vol 48 (4) ◽  
pp. 420-428
Author(s):  
Johana Juliet Caballero Vanegas ◽  
Karen Bibiana Mejía Zambrano ◽  
Lizeth Manuela Avellaneda-Torres
Keyword(s):  
Sustainable Management ◽  
Climatic Variability ◽  
Agricultural Practices ◽  
Enzymatic Activities ◽  
Acid And Alkaline Phosphatase ◽  
Dry Seasons ◽  
Synthetic Fertilizers ◽  
Coffee Agroecosystems ◽  
Alkaline And Acid Phosphatase

ABSTRACT Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.

scholarly journals Long-Term Monitoring Reveals Differential Responses of Mussel and Host Fish Communities in a Biodiversity Hotspot

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 122
Author(s):  
Irene Sanchez Gonzalez ◽  
Garrett W. Hopper ◽  
Jamie Bucholz ◽  
Carla L. Atkinson
Keyword(s):  
Invasive Species ◽  
Life History ◽  
Biodiversity Hotspot ◽  
Biodiversity Hotspots ◽  
Host Fish ◽  
Long Term Monitoring ◽  
Differential Responses ◽  
Taxonomic Groups ◽  
Term Monitoring

Biodiversity hotspots can serve as protected areas that aid in species conservation. Long-term monitoring of multiple taxonomic groups within biodiversity hotspots can offer insight into factors influencing their dynamics. Mussels (Bivalvia: Unionidae) and fish are highly diverse and imperiled groups of organisms with contrasting life histories that should influence their response to ecological factors associated with local and global change. Here we use historical and contemporary fish and mussel survey data to assess fish and mussel community changes over a 33 year period (1986–2019) and relationships between mussel abundance and their host fish abundance in Bogue Chitto Creek, a tributary of the Alabama River and a biodiversity hotspot. Mussel abundance declined by ~80% and community composition shifted, with eight species previously recorded not found in 2019, and a single individual of the endangered Pleurobema decisum. Fish abundances increased and life history strategies in the community appeared stable and there was no apparent relationship between mussel declines and abundance of host fish. Temporal variation in the proportion of life history traits composing mussel assemblages was also indicative of the disturbances specifically affecting the mussel community. However, changes and declines in mussel assemblages in Bogue Chitto Creek cannot be firmly attributed to any specific factor or events because of gaps in historical environmental and biological data. We believe that mobility differences contributed to differential responses of fish and mussel communities to stressors including habitat degradation, recent droughts and invasive species. Overall, our work indicates that monitoring biodiversity hotspots using hydrological measurements, standardized survey methods and monitoring invasive species abundance would better identify the effects of multiple and interactive stressors that impact disparate taxonomic groups in freshwater ecosystems.

scholarly journals Contrasting long-term population trends of beach-nesting shorebirds under shared environmental pressures

2021 ◽  
Vol 260 ◽  
pp. 109178
Author(s):  
Eunbi Kwon ◽  
Samantha Robinson ◽  
Chelsea E. Weithman ◽  
Daniel H. Catlin ◽  
Sarah M. Karpanty ◽  
...  
Keyword(s):  
Population Trends ◽  
Environmental Pressures

Harvest rate of sooty shearwaters (Puffinus griseus) by Rakiura Māori: a potential tool to monitor population trends?

2004 ◽  
Vol 31 (3) ◽  
pp. 319 ◽  
Author(s):  
Jane Catherine Kitson
Keyword(s):  
New Zealand ◽  
Cross Section ◽  
Large Scale ◽  
Population Change ◽  
Population Trends ◽  
Harvest Rate ◽  
General Index ◽  
Careful Screening ◽  
Potential Tool

Sooty shearwaters (tītī, muttonbird, Puffinus griseus) are highly abundant migratory seabirds, which return to breeding colonies in New Zealand. The Rakiura Māori annual chick harvest on islands adjacent to Rakiura (Stewart Island), is one of the last large-scale customary uses of native wildlife in New Zealand. This study aimed to establish whether the rate at which muttonbirders can extract chicks from their breeding burrows indicates population trends of sooty shearwaters. Harvest rates increased slightly with increasing chick densities on Putauhinu Island. Birders' harvest rates vary in their sensitivities to changing chick density. Therefore a monitoring panel requires careful screening to ensure that harvest rates of the birders selected are sensitive to chick density, and represents a cross-section of different islands. Though harvest rates can provide only a general index of population change, it can provide an inexpensive and feasible way to measure population trends. Detecting trends is the first step to assessing the long-term sustainability of the harvest.

Habitat factors related to wild rabbit population trends after the initial impact of rabbit haemorrhagic disease

2006 ◽  
Vol 33 (6) ◽  
pp. 467 ◽  
Author(s):  
Carlos Calvete ◽  
Enrique Pelayo ◽  
Javier Sampietro
Keyword(s):  
Habitat Quality ◽  
Population Trends ◽  
Wild Rabbit ◽  
Pest Species ◽  
Predator Species ◽  
Rabbit Population ◽  
Habitat Factors ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease

The European wild rabbit (Oryctolagus cuniculus) is an introduced pest species in Australia and New Zealand. Rabbits have a devastating negative impact on agricultural production and biodiversity in these countries, and Rabbit Haemorrhagic Disease (RHD) is currently included in control strategies for rabbit populations. On the other hand, the European wild rabbit is a key native prey species in the Iberian Peninsula. Since the arrival of RHD, however, rabbit populations have undergone dramatic decreases and several predator species at risk of extinction are currently dependent on the rabbit population density. Therefore, from the point of view of biodiversity conservation, evaluating habitat correlates and trends of rabbit populations after the first RHD epizootic is of great interest to improve the long-term control or promotion of wild rabbit populations. We estimated the relationship between habitat factors and long-term population trends as well as the relationships between habitat factors and rabbit abundance 2 and 14 years after the arrival of RHD in several Iberian rabbit populations. We observed that only 26% of surveyed populations seemed to experience an increase in rabbit abundance over the last 12 years and that this increase was higher in the low-rabbit-abundance areas of l992, leading to high rabbit abundance in 2004. Our results suggested that short- and long-term impacts of RHD were related to habitat quality. The initial impact of RHD was higher in more suitable habitats, but increasing long-term population trends were positively related to good habitat quality.

Green manure: Alternative to carbon sequestration in a Typic Ustipsamment under semiarid conditions

2018 ◽  
Vol 8 ◽  
Author(s):  
Nelson Virgilio Piraneque Gambasica ◽  
Sonia Esperanza Aguirre Forero ◽  
Adriano Reis Lucheta
Keyword(s):  
Carbon Sequestration ◽  
Cover Crops ◽  
Green Manure ◽  
Block Design ◽  
Climatic Variability ◽  
Plant Cover ◽  
Caribbean Region ◽  
Full Potential ◽  
Semiarid Conditions

Vegetative soil cover mitigates climatic variability and enhances the balance between mineralization and humification processes. Under aerobic conditions, most of the carbon that enters the soil is labile, but a small fraction (1%) is humified and stable, contributing to the soil carbon reserve; therefore, it is important to assess the carbon content captured after green manure cultivation and decomposition. During two consecutive semesters, July to December 2016 and January to June 2017, green manure plots (<em>Zea mays </em>L., <em>Andropogon sorghum </em>subsp.<em> sudanensis </em>and <em>Crotalaria longirostrata</em>) were cultivated individually, in a consortium or amended with palm oil agro-industrial biosolids in a randomized complete block design with 12 treatments. Once decomposed, the different carbon fractions (organic, oxidizable, non-oxidizable, removable and total) were determined. The results showed high total and organic carbon contents under the sorghum treatment, at 30 and 28 Mg ha<sup>-1</sup>, respectively, followed by those under the fallow + biosolid treatment, at 29.8 Mg ha<sup>-1</sup> and 27.5 Mg ha<sup>-1</sup>, respectively. Despite the short experiment duration and the possible contributions of previous management on recalcitrant carbon soil stocks, these findings suggest the importance of maintaining plant cover and utilizing green manure in the Colombian Caribbean region. Long-term experiments may be conducted to confirm the full potential of cover crops on carbon sequestration under tropical semiarid conditions.

scholarly journals Testing Farmers’ Perception of Climate Variability: A Case Study from Kirtipur of Kathmandu Valley

2012 ◽  
pp. 30-34
Author(s):  
Jiban Mani Poudel
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Global Climate ◽  
Climatic Variability ◽  
Global Perspective ◽  
Kathmandu Valley ◽  
Climatic Fluctuations ◽  
Climate Fluctuations ◽  
Global And Local

In the 21st century, global climate change has become a public and political discourse. However, there is still a wide gap between global and local perspectives. The global perspective focuses on climate fluctuations that affect the larger region; and their analysis is based on long-term records over centuries and millennium. By comparison, local peoples’ perspectives vary locally, and local analyses are limited to a few days, years, decades and generations only. This paper examines how farmers in Kirtipur of Kathmandu Valley, Nepal, understand climate variability in their surroundings. The researcher has used a cognized model to understand farmers’ perception on weather fluctuations and climate change. The researcher has documented several eyewitness accounts of farmers about weather fluctuations which they have been observing in a lifetime. The researcher has also used rainfall data from 1970-2009 to test the accuracy of perceptions. Unlike meteorological analyses, farmers recall and their understanding of climatic variability by weather-crop interaction, and events associating with climatic fluctuations and perceptions are shaped by both physical visibility and cultural frame or belief system.DOI: http://dx.doi.org/10.3126/hn.v11i1.7200 Hydro Nepal Special Issue: Conference Proceedings 2012 pp.30-34

scholarly journals On the effect of short-term climate variability on mountain glaciers: insights from a case study

2013 ◽  
Vol 59 (217) ◽  
pp. 992-1006 ◽  
Author(s):  
Daniel Farinotti
Keyword(s):  
Climatic Variability ◽  
Swiss Alps ◽  
Ice Dynamics ◽  
Mountain Glaciers ◽  
Temperature And Precipitation ◽  
Glacier Ice ◽  
Long Term Trends ◽  
Model Set ◽  
Set Up

AbstractStudies addressing the response of glaciers to climate change have so far analyzed the effect of long-term trends in a particular set of meteorological variables only, implicitly assuming an unaltered climatic variability. Here a framework for distinguishing between year-to-year, month-to-month and day-to-day variability is proposed. Synthetically generated temperature and precipitation time series following the same long-term trend but with altered variability are then used to force an ice-dynamics model set up for Rhonegletscher, Swiss Alps. In the case of temperature, variations in the day-to-day variability are shown to have a larger effect than changes at the yearly scale, while in the case of precipitation, variability changes are assessed as having negligible impact. A first set of scenarios is used to show that compared to reference, doubling the temperature variability can reduce glacier ice volume by up to 64% within half a decade. A second set derived from the results of the European ENSEMBLES project, however, shows that such changes are expected to remain below 8% even for extreme scenarios. Although the latter results relativize the importance of the effect in the near future, the analyses indicate that at least caution is required when assuming ‘unchanged variability’.

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