Salit Kark Department of Evolution, Systematics and Ecology

1. Conservation Biology (Ecology) Lecture 3 Nov 2009 Salit Kark Department of Evolution, Systematics and Ecology The Silberman Institute of Life Sciences The Hebrew University of Jerusalem

2. THE CONVENTION ON BIOLOGICAL DIVERSITY (CBD) • Signed by over 150 governments in 1992 in Rio • Became effective as international law in 1993 • First international agreement committing governments to comprehensive protection of the Earth's biological resources  • February 2004, 188 countries and the European Union had ratified the agreement; the U.S. was one of the last nations to sign.

3. THE CONVENTION ON BIOLOGICAL DIVERSITY (CBD) The CBD has three overall goals: • The conservation of biological diversity • The sustainable use of its components, and • The fair and equitable distribution of benefits derived from "genetic resources".

4. THE CONVENTION ON BIOLOGICAL DIVERSITY (CBD) Participating governments agree to carry out various measures to conserve biodiversity: • to create national plans for protection of biodiversity. • to identify ecosystems, species and genomes important for conservation and sustainable use of biodiversity • to monitor biological diversity and any factors that might have impacts on it. • to establish a system of protected areas.

5. THE CONVENTION ON BIOLOGICAL DIVERSITY (CBD) Participating governments agree to carry out various measures to conserve biodiversity: • to manage biological resources to ensure conservation and sustainable use • to rehabilitate and restore ecosystems • to take measures for ex situ conservation.  • The CBD includes agreements for using biological diversity. And governments must provide for "fair sharing" of the benefits derived from genetic resources.

6. Ecosystem services value Example: Pollination services From: The Nature and Value of Australia’s Ecosystem Services: A Framework for Sustainable Environmental Solutions by Steven J. Cork and David Shelton (2000) About 92% of plants worldwide are pollinated by animals. There are more than 1200 vertebrate species and between 100,000 and 200,000 invertebrates involved in pollination of flowering plants. 30% of US food supply by volume depends on animal pollinators, of which bee species (Apoidea) are the most important. but most crops in the USA and Australia are pollinated mainly by introduced honey bees.

7. Example: Pollination services From: The Nature and Value of Australia’s Ecosystem Services: A Framework for Sustainable Environmental Solutions by Steven J. Cork and David Shelton (2000) The value of honey bees to agriculture in the USA is estimated to be US$2–8 billion annually. Many farmers rely on pollinators of the European honeybee (Apis mellifera) that they import temporarily to crop fields to provide pollination during bloom. Honeybees are not always the most effective pollinators of a given crop, and the number of honeybee colonies, both domesticated and feral, have declined by 50–70% since 1946.

8. Example: Pollination services Concern about this heavy reliance on one pollinator species. A “pollination crisis” has been predicted in the US due to a major decline in honey bees caused by a range of diseases and mites. Native, unmanaged bee populations also provide important pollination services to various crops, and are generally more diverse and are abundant near natural habitat It is estimated that other pollinators could take up US$4–7 billion of the service in the USA if they and their habitat were present in sufficient amounts.

9. Example: Pollination services …observed declines in pollination rates and seed set in a range of crops and native plants ...possibly associated with less pollination by native bees due to urbanisation, land clearing and modern agriculture.

10. Example: Pollination services Claire Kremen’s study, Ecology Letters, 2004.

11. Example: Pollination services They studied 22 watermelon (Citrullus lanatus) fields located in California June to August 2000. Farms varied in the proportion of natural habitat (riparian forest, chaparral and oak woodland) found nearby. Also compared organic and 'conventional' farms In northern California, 28 native solitary and two native social bee species pollinate watermelon Assessed bee visitation to watermelon flowers by walking 50 m of row in 10 min. Estimated the mean total number of pollen grains deposited by bees per flower.

12. Example: Pollination services Kremen’s study: For native bees, mean pollen deposition per flower was significantly related to proportion of riparian or upland habitat no significant effect of farm-type (low power) Model: if farmers were to rely entirely on native bee communities for pollination, their farms would need to be situated in areas containing ≥ 40% of natural habitat within a 2.4 km radius as natural habitat, or ≥ 30% within 1.2 km Both the amount and the stability of pollination services from native bees increased with increased proportional area of upland habitats.

13. Example: Pollination services In Australia, a range of native moths, beetles, flies, birds and marsupials are important pollinators of commercial crops. However, the overall potential for native pollinators to substitute for honey bees is unknown. Declining pollination rates of native vegetation in agricultural landscapes Fragmentation and use of pesticides is having impacts on pollination services in Australia and other areas as well.

14. Conservation biology Population level considerations Genetic Demographic Spatial: (m)population dynamics

15. Population Genetics and Conservation Relationship between population size and genetic variability

16. How do we estimate genetic diversity?

17. הוריאביליות הגנטית נובעת מהעובדה שבלוקוס אחד יכול להיות באוכלוסיה יותר מאלל אחד אוכלוסיה בת – 6 פרטים 2 אללים: a ו- b 3 גנוטיפים: ab ,bb ,aa מה תהיינה תוצאות ההגרלה לאחר דור(בהנחה שכל פרט מחליף עצמו בפרט אחד)? תדירות אלל :a p= 8/12= 0.67 הגרלה סטוכסטיות q= 4/12= 0.33 תדירות אלל :b תדירות גנוטיפ aa: p2=0.672=0.44 תצפית: 3 תצפית: 1 תצפית: 2 מס' פרטים צפוי 0.44*6= 2.7 תדירות גנוטיפ bb: q2=0.332=0.11 מס' פרטים צפוי 0.11*6= 0.7 תדירות גנוטיפ ab: 2pq=0.66•0.33=0.44 מס' פרטים צפוי 0.44*6= 2.7 סטית הנחזה מהצפוי אוכלוסיה קטנה, ולכןמספר "ניסוים" קטן Source Uriel Safriel

18. תדירות גנוטיפ aa: p2 q2 תדירות גנוטיפ bb: תדירות גנוטיפ ab: תדירות גנוטיפ ab: 2pq אולם שווי-המשקל ישמר מדור לדור רק באוכלוסיות גדולות כאשר תדירות אלל a היא p ותדירות אלל b היא q תדירות הגנוטיפים קובעת את עמידות האוכלוסיהלגורמי ההכחדה האקראית  סטוכסטיות דמוגרפית סטוכסטיות סביבתית סטוכסטיות הקטסטרופות  מקטינות את האוכלוסיה  חוק הרדי-ויינברג קורס  ההרכב הגנטי משתנה  עמידות האוכלוסיה משתנה בהעדר סלקציה תישמר תדירות זו מדור לדור – חוק הרדי-ויינברג Source Uriel Safriel

19. N גבוה כדי לא לאבד אללים מלוקוס מרובה-אללים אוכלוסיה צריכה להיות גדולה צוואר הבקבוק • כדי לא לאבד אללים נדירים שדווקא הם יסייעו להחלץ מהמצב המסוכן של אוכלוסיה קטנה • האוכלוסיה צריכה להיות גדולה • הקטנה דרסטית בגודל האוכלוסיה (קטסטרופה) •  • הקטנות ב – • שעור ההטרוזיגוטיות • מספר האללים בלוקוס מרובה-אללים • מספר האללים הנדירים • שעור ההטרוזיגוטיות כתוצאה מירידה במספר האללים הנדירים • מספר האללים הנדירים כתוצאה מירידה במספר האללים בלוקוס מרובה-אללים •  • עליה בהסתברות ההכחדה  שונות גנטית גבוהה  עמידות להכחדה מסוכן לכשעצמו N נמוך מצב מסוכן עוד יותר אם צוואר הבקבוק מתארך שונות גנטית נמוכה ↓ פגיעות להכחדה Source Uriel Safriel

20. What is a Population Bottleneck? N RECOVERY An observable and dramatic collapse in numbers CRASH Bottleneck TIME

21. N CRASH INSULAR OR CAPTIVE Bottleneck TIME

22. Whatever the circumstances: a bottleneck is equivalent to taking a relatively small sample of items, in this case genes, from a large population(game…)

23. Loss of genetic variability has multiple aspects • specific alleles will either be lost or retained (maintained) • genetic variance (or heterozygosity) will be lost