Phytophthora species isolations in California wildlands in three counties: Marin, San Francisco, and San Mateo

Transcription

1 Phytophthora species isolations in California wildlands in three counties: Marin, San Francisco, and San Mateo Laura Sims Matteo Garbelotto U.C Berkeley

2 Phytophthora ramorum and the ornamental plant industry 4+ lineages of pathogen worldwide Origin: Vietnam/China? Ornamental trade, worldwide Hundreds of host species Different severity of disease based on species Infected Rhododendron

3 Phytophthora ramorum: Sudden Oak Death Ramorum Blight 4 lineages Origin unknown Ornamental trade, worldwide Hundreds of species Progressive dieback Sudden oak death (West Coast) 1 lineage (NA1 only in California forests) Tens of native species infected Mortality of Fagaceae and Ericaceae Lethal girdling lesions and dieback Introduced via infected ornamentals

4 Croucher et al. Biol Invasions 2013 Repeated introductions and not natural longdistance spread are responsible for extensive SOD distribution. This was determined by presence of identical genotypes at long distance and by coalescent analysis = up to 100% mortality adult tanoaks up to 70% mortality adult oaks

5 Positive (red icons) SOD findings in the 2018 SOD Blitz, a survey run by volunteers. Increase participation from Mount Tam volunteers?

6 Phytophthora species in restoration nurseries Four plant species stand out based on Phytophthora disease incidence Sims and Garbelotto et al Plant Pathology

7 Sampling wildlands- Plant species Diplacus aurantiacus (106 samples) Frangula californica (61 samples) Ceanothus thyrsiflorus (15 samples) Heteromeles arbutifolia (14 samples) Salix lasiolepis (10 samples) Baccharis pilularis (8 samples) Aesculus californica (3 samples) Sims L, Swiecki T, Quinn M, et al. In Press. California Agriculture.

8 Sampling wildlands methods Sampling was to evaluate Phytophthora disease focusing restorations in (1) Marin, (2) San Francisco, and (3) San Mateo Counties: a) restoration areas b) human-impacted areas surrounded by trails/ roads or shared with restoration and stream flooding or trail/road drainage (affected areas) c) unaffected, unplanted (control) areas, may have been previously grazed, wildlife use evident Split upland vs. lowland

9 Impacted areas Sampling wildlands methods

10 Baiting Methods

11 Isolate and ID Processing cultures, identifying species, examining history Identify with morphology, nuclear markers and mitochondrial markers test ability to grow in-vitro with fungicides

12 Results: Marin County Site 1 Site 2 Site 3 Upland Lowland Upland Lowland Upland Lowland Control WGC_ B1_ DIAU_ 1 MBP C_ B1_ DIAU_ 0 BCTC_ B1_ HEAR_ 0 WGC_ B2 _ DIAU_ 0 MBP C_ B2 _ DIAU_ 0 BCTC_ B2 _ HEAR_ 0 WGC_ B3 _ DIAU_ 1 MBP C_ B3 _ DIAU_ 1 BCTC_ B3 _ HEAR_ 0 WGC_ B4 _ DIAU_ 0 MBP C_ B4 _ DIAU_ 0 BCTC_ B1_ DIAU_ 0 WGC_ B5 _ DIAU_ 0 MBP C_ B5 _ DIAU_ 0 BCTC_ B2 _ DIAU_ 0 WGC_ B6 _ DIAU_ 0 MBP C_ B6 _ DIAU_ 0 BCTC_ B3 _ DIAU_ 0 WGC_ B7 _ DIAU_ 0 MBP C_ B7 _ DIAU_ 0 BCTC_ B4 _ DIAU_ 0 WGC_ B8 _ DIAU_ 0 MBP C_ B8 _ DIAU_ 0 BCTC_ B5 _ DIAU_ 0 WGC_ B9 _ DIAU_ 0 BCTC_ B6 _ DIAU_ 0 WGC_ B10 _ DIAU_ 0 BCTC_ B1_ FRCA_ 0 BCTC_ B2 _ FRCA_ 0 BCTC_ B3 _ FRCA_ 0 BCTC_ B4 _ FRCA_ 0 BCTC_ B5 _ FRCA_ 0 Affected WGA_ B1_ DIAU_ 1 BCTA_ B6 _ S ALA_ 0 WGA_B2 _DIAU_0 BCTA_B7 _SALA_1P. pse udoc ryptoge a WGA_B3 _DIAU_1 BCTA_B8 _SALA_1P. pse udoc ryptoge a WGA_ B4 _ DIAU_ 0 BCTA_ B9 _ S ALA_ 0 WGA_ B5 _ DIAU_ 0 BCTA_ B10 _ S ALA_ 0 WGA_B6 _DIAU_0 BCTA_B6 _FRCA_1 P. "taxon kelmania " WGA_ B7 _ DIAU_ 0 BCTA_ B7 _ FRCA_ 0 WGA_B8 _DIAU_0 BCTA_B8 _FRCA_1P. "taxon kelmania " WGA_ B9 _ DIAU_ 0 BCTA_ B9 _ FRCA_ 0 WGA_B10 _DIAU_0 BCTA_B10 _FRCA_1P. "taxon kelmania " BCTA_ B11_ FRCA_ 0 BCTA_B13 _FRCA_1P. pse udoc ryptoge a BCTA_B1_BAPI_1P. "taxon kelmania " BCTA_ B13 _ FRCA_ 2 P. inunda ta Restoration WGR_B1_DIAU_1P. "t kelmania " MBPR_B1_DIAU_0P. pseudocryptogea MBPR_B1_CETH_1P. pseudocryptogea BCTR_B1_DIAU_0 BCTR_B2 _BAPI_0 WGR_B2 _DIAU_0 MBPR_B2 _DIAU_0P. pseudocryptogea MBPR_B2 _CETH_1P. pseudocryptogea BCTR_B2 _DIAU_0 BCTR_B6 _DIAU_1P. "taxon kelmania " WGR_B3 _DIAU_1 MBP R_B3 _DIAU_1P. pse udoc ryptoge a MBP R_B3 _CETH_1P. pse udoc ryptoge a BCTR_B3 _DIAU_1 BCTR_B1_SALA_1 WGR_B4 _DIAU_0 MBPR_B4 _DIAU_1P. pseudocryptogea MBPR_B4 _CETH_1 BCTR_B4 _DIAU_1P. "taxon kelmania " BCTR_B2 _SALA_0 WGR_B5 _DIAU_0 MBPR_B5 _DIAU_1P. megasperma MBPR_B5 _CETH_1P. pseudocryptogea BCTR_B5 _DIAU_1P. "taxon kelmania " BCTR_B3 _SALA_1P. "taxon raspberry" WGR_B6 _DIAU_0 MBPR_B6 _DIAU_0P. megasperma MBPR_B1_FRCA_1P. megasperma BCTR_B3 _FRCA_0 BCTR_B4 _SALA_1P. "taxon kelmania " WGR_B7 _DIAU_0 MBPR_B7 _DIAU_0 MBPR_B2 _FRCA_0 BCTR_B4 _FRCA_0 BCTR_B5 _SALA_1P. "taxon raspberry" WGR_ B8 _ DIAU_ 0 MBP R_ B8 _ DIAU_ 0 MBP R_ B3 _ FRCA_ 0 BCTR_ B1_ FRCA_ 0 WGR_ B9 _ DIAU_ 0 MBP R_ B9 _ DIAU_ 0 BCTR_ B2 _ FRCA_ 0 WGR_B10 _DIAU_0 MBP R_B10 _DIAU_1P. me ga spe rma BCTR_B3 _FRCA_0 MBP R_ B1_ AECA_ 0 BCTR_ B4 _ FRCA_ 0 MBP R_ B2 _ AECA_ 0 BCTR_ B5 _ FRCA_ 0 MBP R_ B3 _ AECA_ 0 BCTR_ B12 _ FRCA_

13 Pythium aff. heterothallicum control Pythium species originally described under Sambucus in Canada and the US in 1968 only appears to be affecting one of the controls blackened foliage, garden snails none, plants on wind swept rocky ledges are smaller A closer look at locations with little or no Phytophthora Pythium species Pythium species affected along trail across road from restoration Pythium IDed by morphology only blackened foliage, plus garden snail remnants P. "taxon kelmania" restoration 2nd P. species from stem canker, sampled this plant three times because it "looked like stem canker and Phytophthora" all three positive stunted Pythium macrosporum Pythium species originally described from diseased roots of flower bulbs in the netherlands some abiotic stress/competition (lots of larger shrubs), poor growth form on some

14 San Francisco County Site 4 Site 5 Site 6 Upland Upland Upland Restoration PBR_B1_DIAU_0 LVR_B1_DIAU_0 CFR_B1_DIAU_0 PBR_B2_DIAU_0 LVR_B2_DIAU_0 CFR_B2_DIAU_0 PBR_B3_DIAU_1P. "taxon kelmania" LVR_B3_DIAU_0 CFR_B3_DIAU_1 PBR_B4_DIAU_0 LVR_B4_DIAU_0 CFR_B4_DIAU_0 PBR_B5_DIAU_0 LVR_B5_DIAU_0 CFR_B5_DIAU_0 PBR_B6_DIAU_1P. "taxon kelmania" LVR_B6_DIAU_0 CFR_B6_DIAU_0 PBR_B7_DIAU_0 LVR_B7_DIAU_1 CFR_B7_DIAU_0 PBR_B8_DIAU_0 LVR_B8_DIAU_0 CFR_B8_DIAU_0 PBR_B1_CETH_0 LVR_B9_DIAU_0 CFR_B1_HEAR_0 PBR_B2_CETH_1P. multivora LVR_B10_DIAU_1 CFR_B2_HEAR_0 PBR_B3_CETH_0 LVR_B1_HEAR_0 CFR_B3_HEAR_0 PBR_B4_CETH_0 LVR_B2_HEAR_1 CFR_B1_BAPI_0 PBR_B5_CETH_0 LVR_B3_HEAR_0 CFR_B2_BAPI_0 PBR_B6_CETH_1P. multivora LVR_B4_HEAR_0 CFR_B3_BAPI_0 PBR_B7_CETH_1P. multivora LVR_B5_HEAR_0 CFR_B4_BAPI_0 PBR_B8_CETH_1P. multivora CFR_B5_BAPI_0 PBR_B9_CETH_0 PBR_B10_CETH_0 PBR_B1_HEAR_0 PBR_B2_HEAR_0 PBR_B3_HEAR_0

15 San Mateo County Site 7 Site 8 Site 9 Upland Lowland Upland Lowland Upland SWC_B1_DIAU_0 SWC_B2_DIAU_0 SWC_B3_DIAU_0 SWC_B4_DIAU_0 SWC_B5_DIAU_0 SWC_B1_FRCA_0 SWC_B2_FRCA_0 SWC_B3_FRCA_1 SWC_B4_FRCA_1 SWC_B5_FRCA_0 SWC_B6_FRCA_0 SWC_B7_FRCA_0 SWC_B8_FRCA_1 SWC_B9_FRCA_0 SWC_B10_FRCA_0 SWA_B1_DIAU_0 SWA_B2_DIAU_0 SWA_B3_DIAU_1 SWA_B4_DIAU_0 SWA_B5_DIAU_0 SWA_B1_FRCA_0 SWA_B2_FRCA_1 SWA_B3_FRCA_0 SWA_B4_FRCA_1 SWA_B5_FRCA_1P. crassamura SWA_B6_FRCA_0 SWA_B7_FRCA_1P. crassamura SWA_B8_FRCA_1P. crassamura SWA_B9_FRCA_1P. crassamura SWA_B10_FRCA_0 MPR_B1_DIAU_0P. species MPR_B2_DIAU_0 MPR_B3_DIAU_0 MPR_B4_DIAU_1 MPR_B5_DIAU_0 MPR_B6_DIAU_0 MPR_B7_DIAU_1P. crassamura MPR_B8_DIAU_1P. crassamura MPR_B9_DIAU_0 MPR_B10_DIAU_1P. crassamura MPR_1B_FRCA_0 MPR_5B_FRCA_1P. crassamura MPR_6B_FRCA_1P. crassamura Control Affected Restoration MPR_2B_FRCA_0 MPR_3B_FRCA_0 MPR_4B_FRCA_0 MPR_7B_FRCA_1P. megasperma MPR_8B_FRCA_1P. crassamura MPR_B9_FRCA_0 MPR_B10_FRCA_0 RCA_B1_FRCA_0 RCA_B2_FRCA_0 RCA_B3_FRCA_1P. multivora RCA_B4_FRCA_1P. multivora RCA_B5_FRCA_0 RCA_B6_FRCA_1P. multivora RCA_B7_FRCA_1P. multivora RCA_B8_FRCA_1P. multivora RCA_B9_FRCA_1P. multivora RCA_B10_FRCA_1P. multivora

16 Phytophthora - Phytophthora +

17 upland restoration D. aurantiacus heavily impacted in some sites, some grasses and cow parsnip filling in where plants died, lowland ephemereal stream areas with F. californica and C. thyrsiflorus also heavily impacted little to no re-growth observed

18 upland B. pillularis self seeded through much of restoration areas and well established around but not within root-rot areas

19 D. aurantiacus stem cankers and root disease

20 C. thyrsiflorus stem cankers, and canopy dieback

21 Results & Discusion: Nurseries vs. Wildlands FRCA Nursery (n=30): FRCA Wildland (n=61): CETH Nursery (30): CETH Wildlands (15): 1. P. crassamura 1. P. crassamura 1. P. multivora 1. P. multivora 2. P. multivora 2. P. multivora 2. P. cactorum 2. P. pseudocryptogea 3. P. pseudocryptogea 3. P. pseudocryptogea 3. P. hedraiandra 4. P. cactorum 4. P. megasperma 4. P. niederhauserii 5. P hybrid: hedraindra and P. cactorum 5. P. taxon kelmania 6. P. inundata DIAU Nursery (n= 20): 1. P. pseudocryptogea DIAU Wildlands (n=106 ): 1. P. pseudocryptogea 2. P. taxon kelmania 2. P. taxon kelmania 3. P. crassamura 3. P. crassamura 4. P. taxon kelmania-type 2 4. P. megasperma

22 So are the Phytophthora species lineages in nurseries the same as the ones in wildlands: the case of P. crassamura

23 North America sampling Italy sampling Wildland Nursery Wildland identical Phytophthora crassamura Cox1 Phylogeny In the US found 4 mitochondrial haplotypes (blue) Wildland So are haplotypes fron nurseries and wildlands the same? Yes, at least 2 haplotypes from nurseries and wildands are the same Wildland identical Nursery Wildland identical Results & Discusion

24 % Growth Survived high doses of fungicide, and continued growth suggesting a history of exposure for nureries and wildlands for P. crassamura and close related taxa RESTORATION (R) VS. NURSERY (N) % GROWTH WITH HIGH DOSE OF FUNGICIDE R N R R R R R R R N N R 0.00

25 Pathogens upland restored vs. upland controls Upland restored 1. P. multivora 2. P. taxon kelmania 3. P. pseudocryptogea 4. P. megasperma 5. P. crassamura 6. Bot canker pathogen(s) 7. Fusarium lateritium 8. Pythium heterothallicum 9. Pyhtium macrosporum Upland controls 1. Fusarium lateritium 2. Pythium heterothallicum 3. Bot canker pathogen(s)

26 Upland Phytophthora vs lowland Upland (~ No. of samples =150) 1. P. multivora 2. P. taxon kelmania 3. P. pseudocryptogea 4. P. megsperma 5. P. crassamura lowland (~ No. of samples =50) 1. P. taxon raspberry 2. P. inundata 3. P. pseudocryptogea 4. P. taxon kelmania 5. P. megasperma 6. P. crassamura 7. P. multivora?- did not sample lowland areas where this species was collected samples from restored and impacted areas only

27 Pathogenicity can change for species already present so reintroduction should be avoided lower virulence (forest isolate 1980s) Same species Greater virulence (nursery isolate 2014) Sims L, Garbelotto M. Forest Pathology. 2018

28 Discussion 1. What are the implications of the detections in these counties on the need to prevent and manage Phytophthora species? 2. What are the logical next steps? 3. What were the unexpected outcomes?

29 1-What are the implications of the detections in these counties on the need to prevent and manage Phytophthora species? i. The most impacted species in nurseries were also impacted in wildlands these were: F. californica, C. thyrsiflorus and D. aurantiacus. Particular caution should be observed when using nursery stock of especially these species. ii. iii. Because pathogens are so widespread in restorations work with land managers to come up with practical solutions perhaps SOPs for rejecting stock. Development of novel management approaches for example consider more practical plant species for sites that are heavily infested. Pathogens are dynamic and evolving in some cases to be more virulent and potentially more problematic. Confirms and reiterates the need for clean plant stock

30 What are the logical next steps? A. Continue and improve the production of clean plant stock in restoration nurseries B. Implement policy that has a backbone (funding and resources for implementation) to slow the spread of Phytophthora species C. Get California commercial nurseries on board so that clean plant production resources are widely accessible and become standard practice, as California plant production is huge and should be a world model, world leader for clean production with the highest standards D. Further study: i. A critical look at ecosystems created/changed through the introduction of various invasive Phytophthora species ii. iii. iv. Examine if species are occuring in an ecological gradient across upland and lowland area and test whether perhaps fidelity (between pathogen and host) changes across a gradient, or in discreet areas (riparian areas vs. upland ones, ie ecotones or community units). Many of the Phytophthora species found are considered new to science and need specific further evaluation. We have looked closely at P. crassamura Test field conditions that may limit Phytophthora survival and spread

31 3-What were the unexpected outcomes? Phytophthora disease in upland areas with no apparent drainage issues Not all restorations have the same outcome in terms of Phytophthora infestation, apparently unaffected restoration were older, extremely well drained phytophthora infected plants may have already died out and plants either were not replaced or replaced by limited species pool High levels of Phytophthora infestations were found in restorations in all three counties examined

32 Acknowledgements The Garbelotto Lab University of California, Agricultural and Natural Resources, Funding National Park Service Alison Foresstel and Michael Chasse The Presidio Trust, Christa Conforti Golden Gate National Parks Conservancy, Alisa Shor The San Francisco Public Utilities Commision, Funding Participating restoration nurseries Phytophthora in Native Habitats Working Group

33 Two of the most important invasive Phytophthora pathways into California wildlands Commercial Nursery 1 Landscape to Wildland Restoration Nursery Restored Wildlands Commercial Nursery 2 Restoration Nursery

34 Concern because new species of Phytophthora in California restoration nurseries and now found in restored wildlands Phytophthora tentaculata Described in Germany in 1993 from Chrysanthemums and other commercial nursery plants First IDed in North America in 2012 in Monterrey Co., California Nursery Kills the California native Diplacus (syn. Mimulus) aurantiacus symptoms typical of other root rotting Phytophthora species Symptoms: root and stem rot, with the roots and stem collars developing necrotic, sunken lesions and few feeder roots, stunting, leaf russeting, and chlorosis, defoliation and dieback of twigs, brown to black lesions girdling the basal stem, and eventually plant death Been identified from nurseries in Butte, Alameda, Placer and Santa Cruz Counties Been recovered from restoration sites in Alameda Co.

35 Close evaluation of restoration sites and nurseries has found many different Phytophthora species from many different plant species Plant species Restoration county Symptoms Phytophthora species Heteromeles arbutifolia San Francisco root rot, root collar canker, foliage discoloration (chlorosis), death P. rosacearum, P. cryptogea, P. cactorum, P. inundata, P. gonapodyides Frangula californica Marin main stem dieback with resprout, chlorosis, root rot, top dieback P. cryptogea, P. multivora Ceanothus thyrsiflorus San Francisco stem and branch dieback, wilting, root-rot, death P. cryptogea, P. cactorum, P. multivora Eriophyllum staechadifolium Marin, San Francisco, San Mateo root rot, dieback, and death P. cryptogea, Phytophthora "megasperma - like", P. crassamura, P. gonapodyides Baccharis pilularis Marin chlorosis, stem necrosis, death Phytophthora "cryptogea -like", P. cryptogea, P. inundata Artemisia californica Marin stem and foliar dieback, necrosis Phytophthora "cryptogea-like" Stuckenia pectinata San Francisco necrotic spotting on seed collected from pond water Phytophthora gonapodyides, P. crassamura Lupinus arboreus Marin Necrosis, foliage dieback, wilting Phytophthora cryptogea

36 Evaluation of toyon field symptoms, plants infected with P. cryptogea root rot root collar canker Phytophthora cryptogea from diseased restoration H. arbutifolia plants

37 Frangula californica infected with Phytophthora multivora No obvious symptoms Phytophthora root rot

38 Phytophthora cactorum and Ceanothus thyrsiflorus Ceanothous root rot caused by Phytophthora species, especially Phytophthora cactorum Symptoms: Root rot, dieback, branch dieback, and death

39 Photos by: Lew Stringer dieback of Ceanothus thyrsiflorus, associated with Phytophthora cryptogea, which was isolated in the field from plants with these types of symptoms -Although in this case not from these particular plants

40 Site with planted Eriophyllum st., and Ceanothus thrys., both associated with P. cryptogea, also remnant Ceanothus thrys. downhill from planting area was positive for P. cryptogea, plants were dying, dead, or had dieback. Photo by: Lew Stringer of the Presidio Trust

41 Frangula california dieback associated with P. multivora Photos by Alison Forestel of NPS

42 With many different Phytophthora species, involved comes differing levels of pathogenicity. Isolate species, and then evaluate which species are responsible for disease observed.

43 How to keep Phytophthora out of wildlands...

44 Nurseries: Integrated approach of sanitation, water management, monitoring, and host selection Start clean stay clean Pathogen free: benches, soil (and other planting media components) containers, and plant propagules -leads to pathogen free plants for landscapes group plants on benches based on their watering needs water appropriately using tensiometers if necessary monitor plants for symptoms weekly select plants that are not hosts

45 Land managers: Prevention first! Prevention: Purchase clean materials Have sites tested first if Phytophthora is present avoid host species Cultural control: Good drainage No sprinklers watering trunks of trees Correct drainage Chemical control: Several fungicides such as Aliette, Alude, Fosphite, Mefenoxam or Subdue may be effective if not phytotoxic to the plants. Fungicides combined with cultural controls work better than either alone

46 Native to AZ and Mexico Introduced on firewood Goldspotted Oak Borer 1 st detected in CA in 2004 San Diego Co survey traps Linked to tree mortality in 2008 Tens of thousands of coast live oak, CA black oak, and canyon live oak trees killed gsob.org

47 California Distribution

48 Risk Sea level to 6,000 feet Prepupae cold tolerance of about -0.4 F

49 Study - Cost of GSOB Remediation Greater San Diego County RCD Project: Removal of Dead Oaks in Descanso Tree removals in diameter Avg height 40 ft Oaks Removed Parcel Acreage house present no house Total Approximate cost $9,000 per parcel $1,200 per acre $1,500 per oak < to > Slide courtesy of Tom Scott, UCR

50 GSOB mitigation costs to date: ~$16 M Possible financial impacts if GSOB becomes established in more populated location? Slide courtesy of Tom Scott, UCR

51 Remediation/Removal Costs for Communities with Oaks Oak density Cost/mile sq Pasadena (23 sq mi) Oaks per acre Oaks per sq mile low medium high low medium high Street Trees , ,000 1,600,000 5,520,000 11,040,000 36,800,000 Yard Trees 4 2,560 1,920,000 3,840,000 12,800,000 44,160,000 88,320, ,400,000 Property Value Losses Associated with Loss of Oaks acre Oak density Cost/mile sq Pasadena (23 sq mi) sq mile Street Trees Yard Trees 4 2,560 Low $5K 1.6 million 13 million Medium $10K High $30K low medium high 3.2 million 26 million 9.6 million 77 million 36 million 294 million 73 million 588 million 220 million 1.8 billion Slide courtesy of Tom Scott, UCR

52 Polyphagous & Kuroshio Shot Hole Borers Female PSHB. A. Eskalen, UC Riverside

53 Invasive Beetle/Disease Complex Polyphagous shot hole borer (PSHB) LA, Orange, Riverside, San Bernardino, and Ventura Counties 3 fungal species Kuroshio shot hole borer (KSHB) San Diego and Orange Counties Closely related to PSHB 2 fungal species Beetle farmer Affects seemingly healthy trees Beetle/fungus affect vascular tissue Internal symptoms on coast live oak. A. Eskalen, UC Riverside

54 More than 200 known hosts Hosts Common urban landscape trees and agriculturally important species Avocado, olive, persimmon At least 35 reproductive hosts 13 native CA species Dead box elder tree, Ontario, CA. A. Eskalen, UC Riverside

55 Distribution of Infestation A. Eskalen, UCR

56 KSHB infestation December in southwestern San Diego County. Kevin Turner UC Riverside (kevint@ucr.edu) Tijuana River Valley Regional Park

57 Photo point December 9, 2015 willows dead, brittle, tops snapping off and falling into the water channel. Note that arundo is the living green plant in the background. Flooding is a concern with so much dead wood falling into the waterway, especially anticipating El Nino.