Trang chủ » Top 9 probability of extinction depends đầy đủ nhất

Top 9 probability of extinction depends đầy đủ nhất

Top 9 probability of extinction depends đầy đủ nhất

Bài viết sau đây sẽ cung cấp cho bạn đầy đủ kiến thức và nội dung về probability of extinction depends mà bạn đang tìm kiếm do chính biên tập viên Làm Bài Tập biên soạn và tổng hợp. Ngoài ra, bạn có thể tìm thấy những chủ đề có liên quan khác trên trang web lambaitap.edu.vn của chúng tôi. Hy vọng bài viết này sẽ giúp ích cho bạn.

Minimum viable population

When a PVA shows that a population has a relatively high risk of extinction, a logical next step would be to determine what could be done to prevent the extinction from happening. In general, protecting larger populations reduces extinction probability (Figure 9.5). To understand exactly how large is large enough, a PVA can also be used to estimate a minimum viable population (MVP). As the name implies, an MVP is the smallest number of individuals necessary for a population to have a chance of long-term persistence, despite the potential effects of demographic, environmental, and genetic stochasticity, and natural catastrophes faced by small populations (Section 8.7). This is well illustrated in the influential paper by Shaffer (1981), who compared setting MVP targets to planning for floods; engineers cannot rely on the average annual rainfall when designing flood control systems near rivers and wetlands. Instead, they must design systems that can also handle extreme rainfall and flooding events. These extreme events may occur rarely, perhaps once every 50 years, but they will likely occur during the lifetime of a flood control system. Similarly, to maximise the long-term protection of a threatened species, we must take actions that protect them in both average and extreme years characterized by catastrophic events such as cyclones/hurricanes, forest fires, and disease epidemics (Anderson et al., 2017). This is especially true considering future climate change scenarios, where every year may be uncharacteristically harsh, in effect a 50-year event.

Figure 9.5 A graph (both axes on log scales) derived from a meta-analysis including 1,198 species showing how a larger minimum viable population (MVP) size translates to a higher likelihood of persistence over time. (A) If the goal is for 50% chance of persistence after 10 years, 100 individuals are required; (B) If the goal is for 90% chance of persistence after 100 years, 3,000 individuals are required; (C) If the goal is for 90% chance of persistence after 1,000 years, 100,000 individuals are required. After Traill et al., 2010, CC BY 4.0.

Several studies have attempted to come up with a “universal” MVP value that could ensure that a population of any species has a reasonable chance of persistence. The estimates vary greatly. For example, a universal MVP estimate from the 1980s, the “50/500 rule”, suggested that at least 50 individuals are necessary to prevent inbreeding, and 500 to prevent genetic drift (Frankham et al., 2014). While this 50/500 rule is currently used to guide the IUCN Red List Criteria for small populations (see e.g. Table 8.1, Criteria D), more recent studies suggested that this estimate is much too low. For example, one study that considered over 1,000 species calculated that 1,377 individuals must be protected to ensure the survival of the population and species (Brooke et al., 2006). Another study argued that 4,169 adults needed to be protected (Traill et al., 2007), while a third study identified 7,316 adults as the universal MVP (Reed et al., 2003). The reason why these estimates are highly variable is because MVPs are context specific, with the results varying greatly by species, location, and degree of threat (Flather et al., 2011). For some species, it might be necessary to protect large numbers of individuals—maybe thousands or tens of thousands for invertebrates and annual plants with that can experience large population size fluctuations. For other species, such as those that are long-lived and reproduce regularly, protecting only a few hundred individuals may suffice. Unfortunately, many threatened species have population sizes much smaller than any of these recommended minimums. For example, half of the 23 surveyed elephant populations remaining in West Africa have fewer than 200 individuals (Bouché et al., 2011), a number considered to be vastly inadequate for their long-term survival, especially in the absence of strong conservation management.

While a universal MVP value will probably never be agreed upon, species and location specific MVP estimates have great value for guiding conservation efforts. For example, it can suggest the minimum number of individuals that need to be released to improve chances of reintroduction success (Section 11.2). MVP estimates can also be combined with a species’ home range requirements to determine a minimum dynamic area (MDA), which is the smallest area of suitable habitat required to sustain the MVP. The use of MVP and MDA, and factors influencing it, were well illustrated in several studies on South Africa’s fragmented cheetah (Acinonyx jubatus, VU) population. Here, researchers originally found that translocations every 1-5 years can greatly improve the likelihood of persistence for 20 subpopulations with at least 10 cheetahs each, or for 10 subpopulations with at least 15 cheetahs each (Lindsey et al., 2009). But a follow-up study then showed that these results were context specific, and highly dependent on the presence of other predators that compete for the same prey (Lindsey et al., 2011). With no competitors, a minimum dynamic area of 200 km2 would be sufficient to support 10 cheetahs. However, a reserve of at least 700 km2 would be needed for 15 cheetahs and 15 lions, and even more if other competitor carnivores are present.

Because of the close relationship between population viability and habitat availability, these two factors are often considered together in population and habitat viability assessments (PHVA, http://www.cpsg.org/our-approach/workshop-processes/phva-workshop-process). Such an assessment was recently performed for Sierra Leone’s western chimpanzees (Pan troglodytes verus, CR), where 53 conservation partners came together to develop a recovery plan for this highly threatened species (Carlsen et al., 2012). As an illustration of how conservation projects can bring people from different walks of life together, the participants for this PHVA came from universities, government, NGOs, and the private sector, and included Paramount Chiefs, representatives from the UN and Sierra Leone’s government ministries, and well as experts in tourism, communications, population modelling, and wildlife rehabilitation.

Top 9 probability of extinction depends tổng hợp bởi Lambaitap.edu.vn

Probability of extinction depends both the

  • Tác giả: cunghocvui.com
  • Ngày đăng: 08/25/2022
  • Đánh giá: 4.88 (789 vote)
  • Tóm tắt: Probability of extinction depends ______ both the population size and fine details of the population demography.Hỗ trợ học tập, giải bài tập, tài liệu miễn …

9. Probability of extinction depends ______ both the population size

  • Tác giả: hoidapvietjack.com
  • Ngày đăng: 03/12/2022
  • Đánh giá: 4.76 (509 vote)
  • Tóm tắt: Probability of extinction depends ______ both the population size and fine details of the population demography. a. on b. in c. from d. for

Xem thêm: Top 8 don t forget lock the door before go to bed chính xác nhất

9. Probability of extinction depends on both the population size and f

  • Tác giả: vi4.ilovetranslation.com
  • Ngày đăng: 01/09/2022
  • Đánh giá: 4.5 (539 vote)
  • Tóm tắt: Probability of extinction depend. 9. Probability of extinction depends on both the population size and fine details of the population demography.

Probability of extinction depends both the population size

  • Tác giả: tuhoc365.vn
  • Ngày đăng: 07/31/2022
  • Đánh giá: 4.39 (343 vote)
  • Tóm tắt: Probability of extinction depends ______ both the population size and fine details of the population demography.

Xem thêm: Top 17 đèn sáng bình thường khi nào đầy đủ nhất

Probability of extinction depends both the population size and fine details of the population demography

  • Tác giả: hoctapsgk.com
  • Ngày đăng: 10/04/2022
  • Đánh giá: 4.02 (477 vote)
  • Tóm tắt: Probability of extinction depends ______ both the population size and fine details of the population demography.Trang tài liệu, đề thi, kiểm tra website …

Probability of extinction depends both the population size and fine details of the population demography

  • Tác giả: cungthi.online
  • Ngày đăng: 01/30/2022
  • Đánh giá: 3.93 (279 vote)
  • Tóm tắt: Probability of extinction depends ______ both the population size and fine details of the population demography. A on B in C from D for.

Xem thêm: Top 10+ auxin có tác dụng kích thích nảy mầm của hạt chính xác nhất

A stochastic model for the probability of malaria extinction by mass

  • Tác giả: europepmc.org
  • Ngày đăng: 09/30/2022
  • Đánh giá: 3.72 (217 vote)
  • Tóm tắt: This paper examines how the probability of stochastic extinction depends on population size, MDA coverage and the reproduction number under control, R c .

Probability of extinction depends both the population size and fine details of the population demography

  • Tác giả: hoc247.net
  • Ngày đăng: 10/05/2022
  • Đánh giá: 3.3 (254 vote)
  • Tóm tắt: Probability of extinction depends ______ both the population size and fine details of the population demography. A. on. B. in.

Answers for Population viability analysis – IELTS reading practice test

  • Tác giả: mini-ielts.com
  • Ngày đăng: 01/22/2022
  • Đánh giá: 3.17 (371 vote)
  • Tóm tắt: This is a tool for predicting the probability that a species will become extinct in a particular region over a specific period. It has been successfully …
  • Khớp với kết quả tìm kiếm: Early attempts to predict population viability were based on demographic uncertainty Whether an individual survives from one year to the next will largely be a matter of chance. Some pairs may produce several young in a single year while others may …
Xem thêm
Scroll to Top