Largest % of global land cover. Perennial native grasslands. > 50% ice free terrestrial landscape Multi-continental range.

Transcription

1

2 Largest % of global land cover > 50% ice free terrestrial landscape Multi-continental range Perennial native grasslands Very IMPORTANT Ecologically Economically picgrassland.jpg 2

3 North American perennial grassland 3,200km North South Southern Canada Texas Rocky Mountains 800km East ~1.3 million km 2 en.wikipedia.org 3

4 Ecological services Wildlife habitat CO 2 sequestration Soil nutrient addition Aquifer recharge Human used products Food Fuel Fiber 4

5 Habitat loss Row crop agriculture Urbanization Climate change Alters ecosystem function creedyassociates.com Habitat degradation Ecological invasion Encroaching and Invading species mobjectivist.blogspot.com 5

6 Process by which: New species enters a community Native or Exotic species Accidental or on purpose 3 Stages Arrival dec.ny.gov Establishment Spread Lockwood et al fortybeads.com blog.tavelpod.comr 6

7 Research concentrations Recruitment limitation Aboveground traits Belowground Little known????? Above- and belowground communities Intrinsically linked Regulate ecosystem-level processes 7

8 Arbuscular mycorrhizal fungi (AMF) Nematodes Bacteria Beneficial Mineral solubilization Fixing nitrogen Access to other soil resources Harmful Parasitic Pathogenic 8

9 ~70% of all vascular plant species Hyphae greatly increase the absorbing surface area 4-20% of plant photosynthate consumed by its AMF Hyphae Arbuscules Drawing by N. C. Johnson Photo by Joe Morton 9

10 Nutrient uptake Plant growth rate Soil nutrient pools Drought tolerance Resistance to root pathogens 10

11 GROWTH RESPONSE (%) SPECIES - 25 % 0 % 25 % 50 % 75 % 100 % Andropogon gerardii Sorghastrum nutans Schizachyrium scoparium Panicum virgatum Bothriochloa bladhii Bouteloua curtipendula Buchloe dactyloides Elymus cinereus Bromus inermis Bouteloua gracilis Pascopyrum smithii Agrostis stolonifera Koeleria macrantha Poa pratensis C 4 C 3 Wilson and Hartnett

12 Van der Putten (2007) Majority of exotic species are non-mycorrhizal Functionally distinct from the native flora In the Great Plains the exotic species introduced resemble the dominant C 4 native species in physiological and functional traits 12

13 Bever, J. D.,1997;

14 Negative Slowed the rate of population growth Increased or stabilized diversity Prominent in native systems Positive Increased rate of species growth Decreased species diversity Resulting in mono-specific stands Bever, J. D.,1997 Bever, J. D. 1994; 1997; 2002;

15 15

16 16

17 Invading native grasslands Reduce plant biodiversity Reduce or alter wildlife biodiversity Hickman et al Restoration concerns Multiple trophic levels Multiple spatial scales 17

18 Old World Bluestem (OWB) Perennial warm season grass Introduced in 1917 Europe, Asia, and Russia Erosion control Increase forage Central and Southern Great Plains Millions of acres Marginal farmlands Road side right of ways Harmoney and Hickman 2004 inspection.gc.ca 18

19 Temporary benefit Unpalatable after maturity Escaped original plantings Invading native prairies Rapid expansion Creating moving fronts OWB better competitors Greater biomass Schmidt et al Hinder native seedlings Wilson et al ca.uky.edu ca.uky.edu 19

20 Non-Sterile + Mycorrhizal fungi Sterile - Mycorrhizal fungi Non-Sterile + Mycorrhizal fungi Sterile - Mycorrhizal fungi Native: Big Bluestem Andropogon gerardii Exotic: Old World Bluestem Bothriochloa sp. 20

21 AM Root Colonization 50 AM Root Colonization (%) NP OWB NP OWB NP OWB NP OWB W. KS E. KS W. OK E. OK Soil Source NP = Soil Collected from Native Prairie OWB = Soil Collected from under Old World Bluestem 21

22 AM Soil Hyphal Abundance Determined by Fatty Acid Analyses nmol/g soil NP OWB NP OWB NP OWB NP OWB W. KS E. KS W. OK E. OK Soil Source NP = Soil Collected from Native Prairie OWB = Soil Collected from under Old World Bluestem 22

23 Invasive/Encroaching C 4 grasses in South Texas Pennisetum ciliare Buffelgrass Dichanthium annulatum Kleberg Bluestem Heteropogon contortus Tanglehead Photos from South Texas Natives 23

24 Collaborative project with Texas A & M Kingsville and South Texas Natives 24

25 Determine if dominant native and invasive C 4 grasses of S. Texas are mycorrhizal dependent. Determine if invasive C 4 grasses alter plantsoil-microbial feedbacks and limit native grass establishment and growth. Determine if addition of native soil amendments improve establishment and growth of native grasses. 25

26 5 reps For each species x soil source x soil treatment Native plant species: Hooded windmillgrass Chloris cucullata Arizona Cottontop Digitaria californica Pink Pappusgrass Pappophorum bicolor Plains Bristlegrass Setaria leucopila Invasive/encroaching species: Tanglehead Heteropogon contortus Buffelgrass Pennisetum ciliare Kleberg Bluestem Dichanthium anulatum 26

27 Soil source: Native Prairie Beneath Tanglehead (encroaching) Beneath Buffelgrass (invasive) Beneath Kleberg Bluestem (invasive) Soil treatments: Field soil (soil left nonsterile) Field soil with native prairie soil inoculum added Steamed (steam-pasteurized) Steamed with native prairie soil inoculum added Harvested after 14 weeks: Quantified above- and belowground biomass 27

28 Pappophorum bicolor Pink Pappusgrass Total Plant Biomass (g) FIELD SOIL STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC Native Prairie Soil H. contortus D. annulatum P. ciliare 28

29 AMF Dependent: Pappophorum bicolor Pink Pappusgrass Seteria vulpiseta Plains Bristlegrass Heteropogon contortus Tanglehead Dichanthium annulatum Kleberg Bluestem Non-AMF Dependent: Chloris cucullata Hooded Windmillgrass Pennisetum ciliare Buffelgrass AMF Facultative: Digitaria californica Arizona Cottontop flickriver.com 29

30 30

31 31

32 Seteria vulpiseta Plains Bristlegrass Total Plant Biomass (g) FIELD SOIL STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC Native Prairie Soil H. contortus D. annulatum P. ciliare 32

33 Chloris cucullata Hooded Windmillgrass Total Plant Biomass (g) FIELD SOIL STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC Native Prairie Soil H. contortus D. annulatum P. ciliare 33

34 Pappophorum bicolor Pink Pappusgrass Total Plant Biomass (g) FIELD SOIL STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC Native Prairie Soil H. contortus D. annulatum P. ciliare 34

35 Invasive/encroaching exotic grasses Have varied reliance on AMF As did the natives Exert differential effects on native grasses Alteration of AMF community Use of native soil amendments may hold potential But where do we get this soil for large projects? May be other mechanisms at work 35

36 Pappophorum bicolor Pink Pappusgrass Total Plant Biomass (g) FIELD SOIL STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC FIELD SOIL FS +INNOC STEAMED S+INNOC Native Prairie Soil H. contortus D. annulatum P. ciliare 36

37 37

38 Assess effects of yellow bluestem (Bothriochloa ischaemum) extractions on germination, survival, and growth of native grasses. Big bluestem (Andropogon gerardii) Little bluestem (Schizachyrium scoparium) Assess effects of yellow bluestem leaf litter on survival and growth of native grasses. 38

39 Ha 1 : Yellow bluestem leachate will reduce germination of native grasses, with no conspecific effects. Ha 2 : Yellow bluestem leachate or litter will reduce biomass production of native grass seedlings, with no conspecific effects. Ha 3 : Yellow bluestem leachate or litter will reduce the survivorship of native grass species, with no conspecific effects. Ha 4 : Big bluestem leachate or litter will have no conspecific or heterospecific effects. 39

40 Germination study: For each species (8 Reps): 50 seeds were placed into a petri dishes 5 ml added to each dish Yellow bluestem leachate (invasive) Big bluestem leachate (native) Deionized water (control) Percent germination was determined Every 3 days for 21 days 40

41 Survivorship and growth study: For each species (8 replicates): One seedling per pot Containing 1 kg native soil 60 ml added Initiation and every other week Yellow bluestem leachate (invasive) Big bluestem leachate (native) Deionized water (control) 20 mm of leaf litter Applied at initiation Yellow bluestem leaf litter (invasive) Big bluestem leaf litter (native) No litter application (control) Percent survival determined after 8 weeks Biomass dried and weighed at 8 weeks 41

42 120 Germination (%) Percent of Control BB Leachate YB Leachate 20 0 Big Bluestem Little Bluestem Yellow Bluestem 42

43 4 3.5 Aboveground Biomass (g) Control BB Lechate YB Leachate Big Bluestem Little Bluestem Yellow Bluestem 43

44 0.6 Aboveground Biomass (g) BB Litter YB Litter Big Bluestem Little Bluestem Yellow Bluestem 44

45 120 Seedling Survival (%) Percent of Control BB Leachate YB Leachate 0 Big Bluestem Little Bluestem Yellow Bluestem 45

46 120 Seedling Survival (%) Percent of Control BB Litter YB Litter 0 Big Bluestem Little Bluestem Yellow Bluestem 46

47 Yellow bluestem leachate profoundly reduced the germination of native seeds, with no conspecific effects. Yellow bluestem leachate and leaf litter significantly reduced the survivorship of native seedlings. 47

48 Big bluestem leachate had little effect on native or invasive species. Big bluestem litter reduced biomass production of all species compared to no litter controls; greater reductions were observed with yellow bluestem litter. Big bluestem litter did not reduce seedling survivorship of any species; yellow bluestem litter profoundly reduced native species survivorship. 48

49 Soil treatments showed no differences EC (soil salinity) or ph Leachates showed only one difference Native leachate had greater phenolic content Native systems = negative feedbacks tolweb.org Bever

50 Invasion may be driven by: Alterations of AMF community Use of allelopathic biochemicals May be a synergistic effect Need for species by species management Future research Assess soil microbial community change Pyro-sequencing Biochemical identification 50

51 Restoration recommendations: Use of native soil addition Restore native soil community Again where do we get the soil? Negate allelopathic compounds Determine residency time of compounds Organic matter addition Aid in restoring soil chemistry Increase restoration success Restore ecosystem function 51

52 52

53 OWB invasion Diverse grasslands vs. monospecific stands Loss of plant biodiversity Loss of wildlife biodiversity Alteration of: Habitat structure Habitat composition Available resources 53

54 Previous work: Cool season exotics Schwartz and Whitson 1987 Hayslett and Danielson 1994 OWB monocultures in Texas Sammon and Wilkins 2005 Found lower small mammal: Diversity Richness Abundance / Relative abundance 54

55 Small mammals Vital to grassland ecosystems Seed dispersers AMF spore dispersers Primary consumers www2.ljworld.com Objectives: To determine if grasslands invaded by OWB contain similar small mammal communities as native grasslands. Determine the vegetative characteristics causing any observed differences. 55

56 56

57 2 treatments 4 Transects 20 traps/transect Sherman live traps 20m spacing >200m between transects 2 years 4 seasons/year 4 days/season 2 checks/day 57

58 Visual obstruction Robel pole Litter Depth Vegetative Composition 1m 2 frame Modified Daubenmire class method Forb, grass, bare ground, etc Native vs. OWB Aerial cover Elevated Daubenmire 5cm, 10cm, 25cm, 50cm virtualbirder.com hosho.ees.hokudai.ac.jp 58

59 Native B. ischaemum +Native Species + Litter Depth + Native Species 5cm + B. ischaemum + Native Species 10cm + B. ischaemum 5cm + B. ischaemum 10cm + B. ischaemum 25cm 59

60 5120 total trap days 24 hrs in 1 day Species Actual Captures Species Native OWB Deer Mouse Cotton Rat Elliot's Short-tailed Shrew 3 10 Fulvous Harvest Mouse 4 1 Prairie Vole 4 7 Hispid Pocket Mouse 1 0 Eastern Harvest Mouse 4 1 White-footed Mouse 2 2 TOTAL

61 Richness Native OWB 61

62 Relative Abundance (%) Native OWB 0.00 Cotton rat Deer Mouse Elliot Short-tailed Shrew Prairie Vole 62

63 63

64 64

65 Cotton rat Increased aerial predator avoidance Major source of mortality Deer mice Increased foraging efficiency vet.osu.com Lower seed recovery in thick litter/vegetation Smaller body size Realanimallife.com 65

66 Native grasslands Higher species richness Higher relative abundances of deer mice OWB invaded grasslands Higher relative abundances of cotton rats Vegetative structure showed few differences May be due to 40-60% invasion vs. monoculture 66

67 OWB invasion leads to: Fewer species Greater abundances of these species Promote early eradication of OWB 60% invasion saw only minor shifts Lag in small mammal community shift Increased fire frequency may maintain native habitat structure Greater ecological concerns 67

68 Invasive species = BIG PROBLEM Economic Concerns $35 billion cost to control or in lost product This does not cover cost of restoration Restoration of invaded lands is complex Focus has been on above ground BUT Current projects show belowground can be just as or even more important 68

69 Invasion may be driven by: Alterations of AMF community Use of allelopathic biochemicals May be a synergistic effect May be more complex Tangled web! Early control and restoration can limit impacts Need for more research 69

70 Funding: OSU- Natural Resource Ecology and Management Texas A & M Kingsville: Tim Fulbright Caesar Kleberg Wildlife Research Institute South Texas Natives David Davidson Konza Prairie Biological Station NSF -LTER Fort Hays State University K-State Hays Ag Experiment Station: Keith Harmoney USDA Range Research Program Project Support: Stuart Wilson (OSU PSS) Chris Stansberry (OSU SRR) Dr. David Lalman OSU Animal Science TX A & M Kingsville Graduate Student: Eric Grahmann OSU Graduate Students: Shubha Shrestha, Morgan Noland, Eric Duell, Stephanie Grischkowsky, and many others Numerous undergraduate research assistants Numerous Volunteers (OSU TWS) 70