if you want to remove an article from website contact us from top.

    what factor is most likely to have caused the change in the number of bird species that occurred between years 30 and 60?

    James

    Guys, does anyone know the answer?

    get what factor is most likely to have caused the change in the number of bird species that occurred between years 30 and 60? from EN Bilgi.

    Climate change causes upslope shifts and mountaintop extirpations in a tropical bird community

    Global warming is predicted to constitute an “escalator to extinction” for species that live on mountains. This is because species are generally moving to higher elevations as temperatures warm, and species that live only near mountaintops may ...Montane species worldwide are shifting upslope in response to recent temperature increases. These upslope shifts are predicted to lead to mountaintop extinctions of species that live only near mountain summits, but empirical examples of populations that ...

    RESEARCH ARTICLE FREE ACCESS SHARE ON

    Climate change causes upslope shifts and mountaintop extirpations in a tropical bird community

    Benjamin G. Freeman https://orcid.org/0000-0001-6131-6832 [email protected], Micah N. Scholer, Viviana Ruiz-Gutierrez, and John W. FitzpatrickAuthors Info & Affiliations

    October 29, 2018 | 115 (47) 11982-11987 | https://doi.org/10.1073/pnas.1804224115

    661 113

    Metrics

    Total downloads 661 Last 12 Months 661 Total citations 113 Last 12 Months 51

    Significance

    Global warming is predicted to constitute an “escalator to extinction” for species that live on mountains. This is because species are generally moving to higher elevations as temperatures warm, and species that live only near mountaintops may run out of room. However, there is little evidence that high-elevation populations are disappearing as predicted. Here, we show that recent warming does indeed act as an escalator to extinction for birds that live on a remote Peruvian mountain. High-elevation species have shrunk in range size and declined in abundance, and several previously common species have disappeared. We suggest that high-elevation species in the tropics are particularly vulnerable to climate change.

    Abstract

    Montane species worldwide are shifting upslope in response to recent temperature increases. These upslope shifts are predicted to lead to mountaintop extinctions of species that live only near mountain summits, but empirical examples of populations that have disappeared are sparse. We show that recent warming constitutes an “escalator to extinction” for birds on a remote Peruvian mountain—high-elevation species have declined in both range size and abundance, and several previously common mountaintop residents have disappeared from the local community. Our findings support projections that warming will likely drive widespread extirpations and extinctions of high-elevation taxa in the tropical Andes. Such climate change-driven mountaintop extirpations may be more likely in the tropics, where temperature seems to exert a stronger control on species’ range limits than in the temperate zone. In contrast, we show that lowland bird species at our study site are expanding in range size as they shift their upper limits upslope and may thus benefit from climate change.

    Sign up for PNAS alerts.

    Get alerts for new articles, or get an alert when an article is cited.

    MANAGE ALERTS

    Climate change is causing many montane species to shift their distributions upslope to track their optimal climate (1–3). Summit-dwelling species lack higher-elevation habitats to receive them and are widely predicted to decline or disappear altogether as upslope shifts drive an “escalator to extinction” (4–6). Indeed, mountaintop extinctions are a primary mechanism underlying the broader projection that climate change alone will lead to extinctions on the order of ∼10% of all eukaryotic species on Earth by 2100 (7, 8). Mountaintop extinctions may be more likely in the tropics, where the nearly flat latitudinal gradient in temperature means that tropical montane taxa are unlikely to persist by shifting to higher latitudes, an option that is more available to taxa in the temperate zone where the latitudinal temperature gradient is much steeper (9). In light of these predictions, conservation biologists and global change researchers have substantial interest in documenting the impact of recent warming on the distributions of high-elevation species. If projections of widespread mountaintop extinctions are valid, we expect to uncover empirical examples of mountaintop populations that have been extirpated associated with recent climate change. However, despite a large literature reporting the geographic responses of species to recent climate change, there are surprisingly few examples of recent mountaintop extirpations plausibly driven by climate change (10).

    Models that predict mountaintop extinctions to be pervasive assume that temperature is the primary factor that controls range limits of montane species. The observation that species are generally shifting toward historically cooler environments associated with recent temperature increases is strong evidence that temperature is indeed a generally important factor limiting species’ distributions, although biotic interactions can also influence range limits (11). Crucially, however, observed range shifts for temperate zone species typically lag far behind those predicted by recent warming (1). In contrast, observed shifts among tropical species roughly match those predicted by climate shifts (12). These observations suggest the hypothesis that current mean temperatures (or perhaps factors tightly correlated with temperature) are a dominant driver of most tropical species’ elevational range limits, while additional factors set range limits of temperate zone species. If so, recent temperature increases may be more likely to cause mountaintop extirpations in tropical populations than in temperate zone ones. While populations of high-elevation tropical species are already threatened due to introduced diseases (13–15) and habitat destruction (16), extirpations of tropical mountaintop populations driven primarily by climate change have yet to be documented.

    We tested the prediction that populations of high-elevation tropical species are threatened by climate change by examining how birds on a remote Peruvian mountain have shifted their elevational distributions in response to recent temperature increases. We compared the results of a modern survey conducted in 2017 with data from a historic survey conducted in 1985 by J.W.F. and colleagues from the Field Museum. This historic survey was specifically designed to document elevational limits of bird species along a ∼8-km river-to-ridgetop transect in the Cerro de Pantiacolla (470 m at the Palatoa River to 1,415 m at the ridge summit) (Fig. 1). This dataset provided the opportunity to test the idea of mountaintop extirpations, because the historic survey documented 16 species of birds that were restricted to the ridgetop (i.e., found only above 1,300 m). Our resurvey, conducted in 2017, covered the same ground at the same time of year and matched the methods of the historic survey ( and , Table S1). The Pantiacolla Transect remains uninhabited by humans and consists of primary evergreen forest. While no anthropogenic land use changes have occurred between historic and modern surveys, annual mean temperatures have increased in the intervening three decades by ∼0.42 °C (). In this region of southeastern Peru, mean annual temperature declines by ∼0.55 °C per 100-m increase in elevation (17). Thus, populations would have to shift upslope by ∼75 m to experience temperature ranges in 2017 comparable with what they experienced in 1985. Based on this expectation, we predicted that, among high-elevation species found along the Pantiacolla Transect, upslope shifts would result in () narrower elevational distributions, () a decline in available area, () concomitant declines in overall abundance, and () the extirpation of at least some species that were previously found only on the ridgetop. We view the Pantiacolla Transect—a narrow trail between a valley bottom and the top of a local ridge—as providing a miniature, real-world model of the same processes that are likely occurring on a larger geographical and elevational scale in the tropical Andes and potentially elsewhere on tropical mountains worldwide.

    Source : www.pnas.org

    EVR 1001 Ch. 4

    Start studying EVR 1001 Ch. 4-7. Learn vocabulary, terms, and more with flashcards, games, and other study tools.

    EVR 1001 Ch. 4-7

    This biome often features wildfires due to extensive dry seasons.

    a. desert b. chaparral

    c. temperate deciduous forest

    d. boreal forest (taiga)

    Click card to see definition 👆

    b. chaparral

    Click again to see term 👆

    What does the left y-axis of the graph represent?

    a. ecological age

    b. number of bird species

    c. number of breeding pairs per 100 acres

    d. stage of ecological succession

    Click card to see definition 👆

    c. number of breeding pairs per 100 acres

    Click again to see term 👆

    1/195 Created by syd_bates4

    Textbook solutions for this set

    Living in the Environment

    19th Edition

    G. Tyler Miller, Scott E. Spoolman

    397 explanations

    Living in the Environment

    19th Edition

    G. Tyler Miller, Scott E. Spoolman

    397 explanations

    Search for a textbook or question

    Terms in this set (195)

    This biome often features wildfires due to extensive dry seasons.

    a. desert b. chaparral

    c. temperate deciduous forest

    d. boreal forest (taiga)

    b. chaparral

    What does the left y-axis of the graph represent?

    a. ecological age

    b. number of bird species

    c. number of breeding pairs per 100 acres

    d. stage of ecological succession

    c. number of breeding pairs per 100 acres

    What does the blue graph line represent?

    a. breeding pairs per 100 acres

    b. species density c. ecological age

    d. number of species

    d. number of species

    After 20 years, what was the total number of bird species?

    a. 14 b. 60 c. 120

    d. cannot be determined from this graph

    a. 14

    In which year was the density of birds greatest?

    a. 20 b. 100 c. 105 d. 160

    e. cannot be determined from this graph

    c. 105

    In which period did the number of species increase most rapidly?

    a. 0 to 20 years b. 20 to 40 years c. 40 to 60 years d. 60 to 100 years e. 100 to 160 years a. 0 to 20 years

    What factor is most likely to have caused the change in the number of bird species that occurred between years 30 and 60?

    a. decreasing food supply

    b. increasing competition among bird species

    c. increasing number of bird habitats

    d. evolution of new bird species

    c. increasing number of bird habitats

    Which of the following statements best describes the bird populations during the period from 100 to 160 years?

    a. Both the number of species and the number of breeding pairs were stable.

    b. The number of species slowly increased, while the number of breeding pairs reached a peak and then slowly declined.

    c. The number species declined slightly, while the number of breeding pairs reached a peak and then declined.

    d. The number of species slowly reached a peak and then slowly declined, while the number of breeding pairs slowly increased.

    b. The number of species slowly increased, while the number of breeding pairs reached a peak and then slowly declined.

    The climax, or final stage, of old-field succession is an oak-hickory forest, which is usually well established after 160 years. What happens to the diversity of bird species after 160 years?

    a. Both the number of species and the number of breeding pairs remain stable.

    b. The number of species remains stable, while the number of breeding pairs slowly declines.

    c. The number of species slowly increases, while the number of breeding pairs slowly declines.

    d. The answer cannot be determined from this graph.

    d. The answer cannot be determined from this graph.

    Two species of lizard live on the same tree and consume the same sorts of food. Regardless, neither species is in direct competition with the other. The key to this scenario is that one of the species is nocturnal; the other is diurnal. What is this called?

    a. parasitism b. symbiosis

    c. resource partitioning

    d. herbivory

    c. resource partitioning

    Sign up and see the remaining cards. It’s free!

    Boost your grades with unlimited access to millions of flashcards, games and more.

    Continue with Google

    Continue with Facebook

    Already have an account?

    Sets with similar terms

    ENV Science exam 2

    87 terms rachel_miller832

    EVR 1001 Chapter 5

    54 terms sophiamagrane

    EVR Chapter 5 (EXAM 2)

    48 terms jackszary

    EVR HW 5 (Exam 2)

    44 terms danielle_schweiger

    Sets found in the same folder

    Chapter 31: Fungi

    35 terms Expediant2

    Biology Ch. 26

    30 terms skhiabani

    BIO 2 EXAM 3

    80 terms ellegurrl

    BIO 2 EXAM 4

    39 terms ashleynelle4

    Other sets by this creator

    SLHS 460 Exam 3

    103 terms syd_bates4

    Athlete Recovery EDCI 270

    5 terms syd_bates4

    EVR 1001 Ch. 15-18

    185 terms syd_bates4

    EVR 1001 Chpt. 12-14

    141 terms syd_bates4

    Verified questions

    ENVIRONMENTAL SCIENCE

    Choose the best answer. Saltwater intrusion is likely to occur when (a) a cone of depression is created near a coastal ecosystem. (b) humans drill into a confined aquifer near the coast. (c) farmers irrigate their crops with an excess of saline water (d) an artesian well is created near the coast.

    Source : quizlet.com

    Population responses of bird populations to climate change on two continents vary with species’ ecological traits but not with direction of change in climate suitability

    Climate change is a major global threat to biodiversity with widespread impacts on ecological communities. Evidence for beneficial impacts on populations i

    Open Access

    Published: 09 October 2019

    Population responses of bird populations to climate change on two continents vary with species’ ecological traits but not with direction of change in climate suitability

    Lucy R. Mason, Rhys E. Green, …Richard D. Gregory

    volume 157, pages

    337–354 (2019)Cite this article

    8164 Accesses 11 Citations 43 Altmetric Metrics details

    Abstract

    Climate change is a major global threat to biodiversity with widespread impacts on ecological communities. Evidence for beneficial impacts on populations is perceived to be stronger and more plentiful than that for negative impacts, but few studies have investigated this apparent disparity, or how ecological factors affect population responses to climatic change. We examined the strength of the relationship between species-specific regional population changes and climate suitability trends (CST), using 30-year datasets of population change for 525 breeding bird species in Europe and the USA. These data indicate a consistent positive relationship between population trend and CST across the two continents. Importantly, we found no evidence that this positive relationship differs between species expected to be negatively and positively impacted across the entire taxonomic group, suggesting that climate change is causing equally strong, quantifiable population increases and declines. Species’ responses to changing climatic suitability varied with ecological traits, however, particularly breeding habitat preference and body mass. Species associated with inland wetlands responded most strongly and consistently to recent climatic change. In Europe, smaller species also appeared to respond more strongly, whilst the relationship with body mass was less clear-cut for North American birds. Overall, our results identify the role of certain traits in modulating responses to climate change and emphasise the importance of long-term data on abundance for detecting large-scale species’ responses to environmental changes.

    Introduction

    Correlational studies over large numbers of species, regions and taxonomic groups have revealed clear associations between recent climate change and observed changes in geographical range and abundance of many plant and animal taxa (Hickling et al. 2006; Parmesan and Yohe 2003; Spooner et al. 2018; Stephens et al. 2016). The evidence for positive changes in species abundance and distribution in response to beneficial recent climate change (i.e. in regions where this will lead to abundance increases and range extensions) is generally perceived to be stronger and more plentiful than for populations expected to be negatively impacted (e.g. Frishkoff et al. 2016; Parmesan et al. 1999; Parmesan and Yohe 2003; Root et al. 2003; Thomas et al. 2006; Thomas and Lennon 1999). However, this effect may be an artefact, particularly if there are time lags in the responses of populations to climate change, or if range retractions are more difficult to detect than expansions. For example, climate change may adversely affect an animal species through changes in vegetation affecting the suitability of its habitat, which take time to occur, leading to an extinction debt (Kuussaari et al. 2009). Such time lags may act in the opposite direction too, resulting in instances where beneficial effects, and therefore, the responses of species predicted to benefit may be delayed (Menéndez et al. 2006), but this would not explain the suggested excess of positive relative to negative effects on species distribution and population changes.

    Range retractions may be more difficult to detect than expansions, particularly when occurrence is mapped at a coarse scale. Range expansion requires successful colonisation of a new site beyond the current range by a small number of individuals, whilst range retraction may require the extinction of many local populations (Thomas et al. 2006; Brommer et al. 2012). Furthermore, the biological process of extinction may constitute a longer-term process than colonisation, which may not be detected in the relatively short time periods considered by many studies of range change (Brommer et al. 2012). Finally, attributing range retractions solely to climatic change is difficult. Range expansion in areas of degraded habitat can easily be attributed to improving climatic conditions. However, apportioning the cause of range retractions among a suite of threatening processes, including habitat degradation and invasive species, is much harder (Thomas et al. 2006). Despite some evidence for the negative effects of climate change on populations (Lehikoinen et al. 2019), there is still no consensus on whether the reported difference in strength and quantity of evidence for positive relative to negative effects of climate change is an artefact or a true reflection of species’ responses. A large-scale, multispecies assessment of the positive relative to negative effects of climate change on species’ populations would provide important insights into the cause of this apparent disparity.

    In some studies investigating the impacts of climate change, species distribution models (SDMs) relating geographical distribution to climatic variables are combined with annual meteorological data to estimate the direction and magnitude of changes in climate suitability over a given time period for different species or regions (Engler et al. 2017; Stephens et al. 2016). Variation in observed population changes, both among species in a given area and among regions for a given species, can then be compared to the modelled differences in climate suitability trend. A positive relationship between observed and expected change is taken as correlational evidence of a probable population-level response of distribution and/or abundance to climatic change (although see Clavero et al. 2011). Such studies have found positive relationships between climate suitability and population trend, as expected, but have also identified substantial residual variation in the observed changes in distribution and abundance that is not accounted for statistically by measures of climatic change (Green et al. 2008; Stephens et al. 2016).

    Source : link.springer.com

    Do you want to see answer or more ?
    James 10 month ago
    4

    Guys, does anyone know the answer?

    Click For Answer