Search results for "Earth"

Land-use and climate related drivers of change in the reindeer management system in Finland: geography of perceptions

2021

Drivers of change in the reindeer management system are rather well-known. But when developing the gover-nance to support the traditional livelihoods, it is crucial to understand also practitioner perceptions. Systematic research on these is lacking. We analyzed the land-use and climate related drivers within the reindeer man-agement area (RMA) in Finland, and, using a perception geography approach, studied the herder perceptions towards these. We conducted an on-site questionnaire survey with herders from 51 herding districts. Factors directly affecting the welfare of reindeer were perceived as crucial by herders, for example basal icing affecting the forage availability, and land-use rela…

Ticket to spawn: Combining economic and genetic data to evaluate the effect of climate and demographic structure on spawning distribution in Atlantic…

2019

Abstract Climate warming and harvesting affect the dynamics of species across the globe through a multitude of mechanisms, including distribution changes. In fish, migrations to and distribution on spawning grounds are likely influenced by both climate warming and harvesting. The Northeast Arctic (NEA) cod (Gadus morhua) performs seasonal migrations from its feeding grounds in the Barents Sea to spawning grounds along the Norwegian coast. The distribution of cod between the spawning grounds has historically changed at decadal scales, mainly due to variable use of the northern and southern margins of the spawning area. Based on historical landing records, two major hypotheses have been put f…

Climate Change and Migration for Scandinavian Saami: A Review of Possible Impacts

2019

Migration, especially of indigenous peoples, related to or influenced by climate change continues to gain increasing research and policy attention. Limited material remains for this topic for Scandinavia&rsquo

Macrophytes shape trophic niche variation among generalist fishes.

2017

Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation…

Partitioning net carbon dioxide fluxes into photosynthesis and respiration using neural networks

2020

Abstract The eddy covariance (EC) technique is used to measure the net ecosystem exchange (NEE) of CO2 between ecosystems and the atmosphere, offering a unique opportunity to study ecosystem responses to climate change. NEE is the difference between the total CO2 release due to all respiration processes (RECO), and the gross carbon uptake by photosynthesis (GPP). These two gross CO2 fluxes are derived from EC measurements by applying partitioning methods that rely on physiologically based functional relationships with a limited number of environmental drivers. However, the partitioning methods applied in the global FLUXNET network of EC observations do not account for the multiple co‐acting…

The unique inflorescence structure of Dorema aucheri (Apiaceae): An adaptation to the arid environment

2021

Abstract Arid environments demand specific adaptations from plants in vegetative and reproductive systems. Self–compatibility, high pollen production and few well developed fruits are adapted to increase sexual reproductive success. Dorema aucheri is an arid–adapted, perennial monocarpic species endemic to southern Iran. It has a unique inflorescence structure. In this study, significance of inflorescence architecture for reproductive success was investigated in a wild population. The huge yellow inflorescences were frequently visited by manifold insects. The species is andromonoecious and spatially subdivided in a distal part with perfect flowers and a proximal part with male flowers. Flow…

Adapted conservation measures are required to save the Iberian lynx in a changing climate

2013

The Iberian lynx ( Lynx pardinus ) has suffered severe population declines in the twentieth century and is now on the brink of extinction 1 . Climate change could further threaten the survival of the species 2 , but its forecast effects are being neglected in recovery plans 3,4 . Quantitative estimates of extinction risk under climate change have so far mostly relied on inferences from correlative projections of species’ habitat shifts 5 . Here we use ecological niche models coupled to metapopulation simulations with source–sink dynamics 6,7 to directly investi- gate the combined effects of climate change, prey availabil- ity and management intervention on the persistence of the Iberian lyn…

The influence of temperature model assumptions on the prognosis accuracy of extinction risk

2000

Abstract For a species whose abundance is well-known to correlate on the degree of heat different temperature model assumptions may affect the prognosis accuracy of persistence. Likewise, year-to-year autocorrelations in weather fluctuations are known to decrease extinction risk. Thus, we investigated the grey bush cricket Platycleis albopunctata . For this species is known that growth and reproduction is mainly influenced by temperature. We developed a stochastic individual based model for the bush cricket. This day–degree model described the demographic growth of the species that depends on temperature. Daily temperatures were generated by five different methods: (i) temperatures were seq…

2018

The Atlantic surfclam (Spisula solidissima) is a commercially important species in North American waters, undergoing biological and ecological shifts. These are attributed, in part, to environmental modifications in its habitat and driven by climate change. Investigation of shell growth patterns, trace elements, and isotopic compositions require an examination of growth lines and increments preserved in biogenic carbonates. However, growth pattern analysis of S. solidissima is challenging due to multiple disturbance lines caused by environmental stress, erosion in umbonal shell regions, and constraints related to sample size and preparation techniques. The present study proposes an alternat…

Life history and spatial distribution of the enchytraeid wormCognettia sphagnetorum(Oligochaeta) in metal-polluted soil: Below-ground sink-source pop…

2001

We studied the life history, metal-avoidance behavior, spatial distribution, and population growth of enchytraeid worms (Cognettia sphagnetorum [Oligochaeta]) originating from two sites: one uncontaminated, and another patchily polluted by heavy metals. Effects of patchy soil contamination on populations were studied in microcosms. In uncontaminated soil, worms from the polluted site had lower viability and reduced growth rate as juveniles but higher growth rate as adults compared to worms from the unpolluted site. They were also smaller in size at fragmentation (reproduction). Worms from the polluted site reached a larger population size than worms from the unpolluted site. Hence, worms fr…