Monitoring Ecosystem Health

Transcription

1 Monitoring Ecosystem Health ESRM 150 Autumn 2015 What is a healthy ecosystem? We propose that a healthy ecosystem is one that is sustainable that is, it has the ability to maintain its structure (organization) and function (vigor) over time in the face of external stress (resilience). Costanza and Mageau (1999) Ways to monitor ecosystem health Monitor all species in a system 1

2 Ways to monitor ecosystem health Monitor all species in a system What potential problems may accompany this approach? Ways to monitor ecosystem health Ways to monitor ecosystem health Simplifies it to focus on a specific species or suite of species or monitor the habitat itself 2

3 Ways to monitor ecosystem health Monitor all species in a system Keystone species Umbrella species Indicator species Remote sensing What do you need to know to select the correct species? Usually need long term data sets Life-history and basic biology Reproduction Lifespan Trophic level Etc. Population dynamics and BIDE Source-sink The connections between species in the system Top down versus bottom up and trophic cascades Life History Traits An organism's life history is the sequence of events related to survival and reproduction that occur from birth through death. r (fast species) Unstable environment, density independent, quantity K (slow species) Stable environment, density dependent, quality 3

4 r (fast species) K (slow species) Organism size Small Large Energy used to make each individual Low High # Offspring produced Many Few Timing of maturation Early Late (much parental care) Life expectancy Short Long Lifetime reproductive events Few Many Are endangered species often r or K? What about successful invasive species? Population Dynamics B I D E Population Dynamics B I D E 4

5 Population Dynamics Need to know about movement and dispersal between populations Can be difficult to study Metapopulation or an Isolated Population? Population Dynamics: Source-sink dynamics Think about a faucet. You have the spout (source) and the drain (sink). Water moves from the spout to the drain. Source-sink dynamics Source Can be large area Lots of breeding Animals leave this area and move to other habitats (often smaller) Sink Often smaller area Animals moving to this area from the source population Often high levels of mortality here Something attractive about this habitat (excess resources, unused space, etc.) 5

6 Structures 1/26/2016 Source-sink dynamics Interspecific Connections: Top down versus bottom up control Ongoing debate TOP DOWN Apex Predator BOTTOM UP Apex Predator Most likely often a mixture of both in many systems Prey Species Meso-carnivores Prey Species Structure Meso-carnivores Top down 6

7 Abundance 1/26/2016 Bottom Up Large Fish (Eat Small Fish) Small Fish (Eat Zooplankton) Zooplankton (Eat Phytoplankton) Phytoplankton (Primary Producers) Time Trophic Cascades Addition/removal of predators alters entire ecosystem structure Classic examples (sea otters, wolves) Good Morning! Come and pickup a notecard Only one per student 7

8 Quiz #3 Put your name on your note card You get credit for being here whether you get the question right or not This is quiz 3 out of 4 Quiz #3 1. Name two of the four major types of pollution? 2. Do endangered species tend to be r species or k species? Quiz #3 1. The four major types of pollution 1. Solid waste 2. Chemical waste 3. Noise pollution 4. Light pollution 2. Do endangered species tend to be r species or k species? 8

9 Quiz #3 1. The four major types of pollution 1. Solid waste 2. Chemical waste 3. Noise pollution 4. Light pollution 2. Do endangered species tend to be r species or k species? k-species Beluga whale (Delphinapterus leucas) Ways to monitor ecosystem health Monitor all species in a system Keystone species Umbrella species Indicator species Remote sensing 9

10 Keystone Species Term coined by R Paine (1969) A keystone species is a species that exerts an impact on its community that is both strong and disproportionate to its abundance. The keystone analogy refers to the architectural element at the apex of an arch that locks the other pieces into position, and is used colloquially to refer to the supporting element of a larger structure. Encyclopedia of Earth What are some examples of keystone species? Keystone species characteristics Historically a top predator Now include species which exert influence through other interactions Competition (apex predators control on mesopredators) Mutualism (birds and fruit) Pollination (honey bees) Dispersal (elephants and grasslands) Etc. Any species that s presence or absence affects the composition of the rest of the ecosystem Removal or addition often leads to trophic cascades Keystone Species Sea Otters 10

11 Keystone Species Sea Stars What influence on a system does Pisaster, a top predator, have? Removed Pisaster from some intertidal areas but maintained other areas as a control Monitored species diversity in areas with Pisaster and in areas where it was absent. What do you think they found in terms of biodiversity? Keystone Species Sea Stars Why might it be difficult to use keystone species to monitor ecosystem health? Keystone species difficulties Intensive to determine which species are a keystone Requires an understanding of the system as a whole The absence of that species may be one of the few ways to determine a true keystone species Other than assuming it s a top predator, difficult to target 11

12 What is an umbrella species? The concept of an umbrella species has been used by conservation practitioners to provide protection for other species using the same habitat as the umbrella species. As the term implies, a species casts an umbrella over the other species by being more or equally sensitive to habitat changes. Thus monitoring this one species and managing for its continued success results in the maintenance of high quality habitat for the other species in the area. Encyclopedia of Life What is an umbrella species? Umbrella species characteristics and uses Usually have large home ranges Cover multiple habitats Usually large species, often mammals Select a wide-ranging species and determine how much habitat it requires. Maintain that habitat and you should protect other species 12

13 Umbrella species characteristics and uses Usually have large home ranges Cover multiple habitats Usually large species, often mammals Select a wide-ranging species and determine how much habitat it requires. Maintain that habitat and you should protect other species Why might umbrella species not be effective in monitoring ecosystem health? Umbrella species challenges Disagreement on characteristics It s habitat may not overlap or encompass that of other species May only show larger, landscape wide processes and miss fine scale What is an indicator species? An indicator species is an organism whose presence, absence or abundance reflects a specific environmental condition. Indicator species can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem. -Encyclopedia of Life 13

14 Indicator Species - Canary in the Coal Mine Why use an indicator species? Allow measurements of complex systems Can tell us about the health of an entire ecosystem (terrestrial, ocean, freshwater, etc.) Used as an early warning system = canary in the coal mine Indicator Species Use Been used to monitor: Toxic gasses (mosses and lichens) Water quality (amphibians) Old growth habitat (spotted owls) Overall ecosystem health (Magellanic penguins) Many others 14

15 Indicator Species Characteristics What type of species would be best to focus on? Highly sensitive or adaptable Widespread or localized Feed on specific species or opportunistic Charismatic or unknown What do you think? Why might indicator species not work well for monitoring overall ecosystem health? Pitfalls of indicator species Can be difficult to pinpoint actual cause of declines If the wrong species is chosen could miss a trend If a species doesn t have the right characteristics you may not see impact on ecosystem until it is too late Correlation causation (must be careful of this) Keystone versus umbrella versus indicator A single species can be all three if it has significant effect on the structure of the system, is wide ranging, and is a good indicator of ecosystem health Umbrella species may not be good indicators of overall ecosystem health since often they are resilient, adaptable, and may not represent the whole system. If you protect this species you protect all that rely on parts of its range. Indicator can be highly sensitive (water/air quality) or less sensitive. Research on this species should indicate something about the ecosystem as a whole 15

16 What is remote sensing? Remote sensing is the science of obtaining information about objects or areas from a distance, typically from aircraft or satellites. -NOAA Remote sensing applications Can be used to establish and monitor protected areas Traditionally done in terrestrial systems May be applicable in aquatic systems Can also be used to predict areas of importance for species Useful to assess areas where it is difficult to collect data Useful for monitoring anthropogenic pressure Basilisk Lizard (Basiliscus sp.) 16

17 Remote sensing in terrestrial systems Using reflectance, you can assess the amount and distribution of primary producers Imagery allows the monitoring of overall habitat size Can monitor habitat conversion/burning UAV s may allow real time counting of animal species Usually combined with on the ground work for max efficiency Remote sensing and cross-river gorillas Cross-river gorilla (Gorilla gorilla diehli) Most endangered African ape Habitat loss and bushmeat hunting primary reasons Are there possibly more populations out there than currently known? Can remote imaging predict areas where one might find gorillas? Remote sensing and cross-river gorillas 17

18 Remote sensing and cross-river gorillas Used landsat images to categorize habitat Identified potential corridors and gained an understanding of fragment sizes Found what appeared to be corridors and determined areas where previously unknown populations may exist Went out and surveyed Remote sensing and cross-river gorillas Ground surveys found previously unknown populations by checking areas found using remote sensing Increased the estimated population Genetic samples showed there was connection between populations previously thought isolated so corridors existed Remote sensing in marine systems Chlorophyll concentration and primary producers Sea Surface Temperature Wind Speed Bathymetry 18

19 Remote sensing in marine systems Anthropogenic effects High versus low resolution Developing countries often are areas of low resolution. Why is this particularly problematic? Shortcomings of remote sensing Can be only surface level (difficult to penetrate canopies or deep into oceans) Often very expensive Problems with resolution Complicated to work with Without people on the ground may only show general patterns 19

20 Why should you care about healthy ecosystems? Why should you care about healthy ecosystems? Why should you care about healthy ecosystems? Intact ecosystems are tied to food security Sufficient water and soil for agriculture Help regulate climate Provide food from terrestrial and marine systems Prevents soil erosion Provides pollination, natural fertilization, and pest control Source of biopharmaceuticals 20 new natural drugs between Chemical in bee venom recently found to fight HIV 20

21 Why should you care about healthy ecosystems? Can help protect from extreme events Counter climate change Mangroves and coral protect against storm surge Communities near mangroves did better during 2004 Asian Tsunami Keep soil intact, avoid landslides Improved mental health Greener environment=better mental health Decreased anxiety and depression Can decrease prevelance of communicable diseases Past disease outbreaks tied to habitat loss Lyme disease actually lower infection rate in conserved habitats = dilution effect Take home messages Multiple methods exist for monitoring ecosystem health Best method is probably system dependent Best overall approach is often a combination If you understand the biology of species in a system and the dynamics, focusing on a single species can save time and manpower 21