Friends with benefits: The effects of vegetative shading on plant survival in a green roof environment

Autoři: Axton C. Aguiar aff001;  Sharon A. Robinson aff001;  Kristine French aff001
Působiště autorů: Centre for Sustainable Ecosystem Solutions, School of Earth, Atmosphere and Life Sciences, University of Wollongong, Wollongong, NSW, Australia aff001
Vyšlo v časopise: PLoS ONE 14(11)
Kategorie: Research Article
doi: 10.1371/journal.pone.0225078


Green roofs help ameliorate some of the adverse social, economic and environmental effects of urbanisation. However, green roofs are harsh environments for plants, as they must cope with shallow soils, low nutrient availability, high solar radiation, low water availability and high pollution/disturbances. The effect of shade plants on vegetation survivability was investigated using green roof mesocosms with four different native species pairs (shade plant and a target ground cover plant). To examine the effect of shading and competition on plant growth and survival, plant pairs were subjected to four treatments; naturally shaded with a shade plant shading the target plant, artificially shaded with an artificial plant shading the target plant, unshaded natural which had a trimmed shade plant providing no shade to the target plant and an unshaded treatment with the target plant being the sole occupant of the mesocosm. The experiment ran for 11 months with measurements taken monthly to record growth and visual health of the target plant. Soil moisture and biomass data was collected at the end of the experiment. Overall, natural shade treated plants had the highest biomass while unshaded plants had the lowest biomass. Contrary to our predictions, the shaded artificial and the unshaded natural had similar moderate biomass. This similarity suggests that while shading had a positive influence on plant growth, there was also a positive influence of growing with a shade plant which is not accounted for by shading. The results highlight the complexity of biotic relations between plants and emphasises that the presence of a nurse plants can be benefit to the survival and growth of other species within a green roof ecosystem.

Klíčová slova:

Biomass – Edaphology – Leaves – Plant growth and development – Root growth – Solar radiation – Species interactions – Mesocosms


1. United Nations. World Urbanization Prospects: The 2018 Revision. United Nations Department of Economic and Social Affairs; 2019.

2. McGranahan G, Satterthwaite D. Urbanisation: concepts and trends. IIED London; 2014.

3. McKinney ML. Urbanization, Biodiversity, and ConservationThe impacts of urbanization on native species are poorly studied, but educating a highly urbanized human population about these impacts can greatly improve species conservation in all ecosystems. Bioscience. 2002;52: 883–890.

4. Sol D, González-Lagos C, Moreira D, Maspons J, Lapiedra O. Urbanisation tolerance and the loss of avian diversity. Ecol Lett. 2014;17: 942–950. doi: 10.1111/ele.12297 24835452

5. Moghbel M, Erfanian Salim R. Environmental benefits of green roofs on microclimate of Tehran with specific focus on air temperature, humidity and CO2content. Urban Clim. 2017;20: 46–58. doi: 10.1016/j.uclim.2017.02.012

6. Oberndorfer E, Lundholm J, Bass B, Coffman RR, Doshi H, Dunnett N, et al. Green Roofs as Urban Ecosystems: Ecological Structures, Functions, and Services. Bioscience. 2007;57: 823–833. doi: 10.1641/B571005

7. Zhang Z, Szota C, Fletcher TD, Williams NSG, Werdin J, Farrell C. Influence of plant composition and water use strategies on green roof stormwater retention. Sci Total Environ. 2018;625: 775–781. doi: 10.1016/j.scitotenv.2017.12.231 29306165

8. Cook-Patton SC, Bauerle TL. Potential benefits of plant diversity on vegetated roofs: A literature review. Journal of Environmental Management. Elsevier Ltd; 2012. pp. 85–92. doi: 10.1016/j.jenvman.2012.04.003 22575204

9. Oberndorfer E, Lundholm J, Bass B, Coffman RR, Doshi H, Dunnett N, et al. Green Roofs as Urban Ecosystems: Ecological Structures, Functions, and Services. Bioscience. 2007;57: 823–833. doi: 10.1641/B571005

10. Williams NSG, Lundholm J, MacIvor JS. Do green roofs help urban biodiversity conservation? J Appl Ecol. 2014;51: 1643–1649. doi: 10.1111/1365-2664.12333

11. Lee KE, Williams KJH, Sargent LD, Williams NSG, Johnson KA. 40-second green roof views sustain attention: The role of micro-breaks in attention restoration. J Environ Psychol. 2015;42: 182–189.

12. Lundholm JT. Green roof plant species diversity improves ecosystem multifunctionality. J Appl Ecol. 2015;52: 726–734. doi: 10.1111/1365-2664.12425

13. Arabi R, Shahidan MF, Kamal M, Zaky MF, Ja ‘afar B, Rakhshandehroo M. Considerations for Plant Selection in Green Roofs. Alam Cipta, Int J Sustain Trop Des Res Pract. 2015;8: 10–17.

14. Lundholm JT, Walker EA. Evaluating the Habitat-Template Approach Applied to Green Roofs. Urban Nat. 2018; 39–51. Available:

15. Lundholm JT, Richardson PJ. MINI‐REVIEW: Habitat analogues for reconciliation ecology in urban and industrial environments. J Appl Ecol. 2010;47: 966–975.

16. Lavorel S, Grigulis K, Lamarque P, Colace MP, Garden D, Girel J, et al. Using plant functional traits to understand the landscape distribution of multiple ecosystem services. J Ecol. 2011;99: 135–147. doi: 10.1111/j.1365-2745.2010.01753.x

17. Van Mechelen C, Dutoit T, Kattge J, Hermy M. Plant trait analysis delivers an extensive list of potential green roof species for Mediterranean France. Ecol Eng. 2014;67: 48–59. doi: 10.1016/j.ecoleng.2014.03.043

18. Ksiazek-Mikenas K, Köhler M. Traits for stress-tolerance are associated with long-term plant survival on green roofs. J Urban Ecol. 2018;4: 1–10. doi: 10.1093/jue/juy016

19. Benvenuti S, Bacci D. Initial agronomic performances of Mediterranean xerophytes in simulated dry green roofs. Urban Ecosyst. 2010;13: 349–363. doi: 10.1007/s11252-010-0124-9

20. Brooker RW, Maestre FT, Callaway RM, Lortie CL, Cavieres LA, Kunstler G, et al. Facilitation in plant communities: The past, the present, and the future. Journal of Ecology. 2008. pp. 18–34. doi: 10.1111/j.1365-2745.2007.01295.x

21. Mcintire EJB, Fajardo A. Facilitation as a ubiquitous driver of biodiversity. New Phytol. 2014;201: 403–416. doi: 10.1111/nph.12478 24102266

22. Billings WD, Mooney HA. The ecology of arctic and alpine plants. Biol Rev. 1968;43: 481–529.

23. Grime JP. Competitive exclusion In herbaceous vegetation. Nat. 1973;242: 344–347. doi: 10.1038/242344a0

24. Callaway RM. Positive interactions among plants. New York Bot Gard Press. 1995;61.

25. Brooker RW, Callaghan T V. The balance between positive and negative plant interactions and its relationship to environmental gradients: a model. Oikos. 1998; 196–207.

26. Connell JH. On the prevalence and relative importance of interspecific competition: evidence from field experiments. Am Nat. 1983; 661–696.

27. Callaway RM. Positive interactions and interdependence in plant communities. Springer, Dordrecht, The Netherlands. Springer; 2007.

28. López RP, Valdivia S, Sanjinés N, De La Quintana D. The role of nurse plants in the establishment of shrub seedlings in the semi-arid subtropical Andes. Oecologia. 2007;152: 779–790. doi: 10.1007/s00442-007-0698-y 17390151

29. Wright A, Schnitzer S, Reich P. Living close to your neighbors-the importance of both competition and facilitation in plant communities. Ecology. 2014;95: 2213–2223. doi: 10.1890/13-1855.1 25230472

30. Molenda O, Reid A, Lortie CJ. The alpine cushion plant Silene acaulis as foundation species: A bug’s-eye view to facilitation and microclimate. PLoS One. 2012;7. doi: 10.1371/journal.pone.0037223 22655035

31. Butler C, Orians CM. Sedum cools soil and can improve neighboring plant performance during water deficit on a green roof. Ecol Eng. 2011;37: 1796–1803. doi: 10.1016/j.ecoleng.2011.06.025

32. Anthelme F, Dangles O. Plant–plant interactions in tropical alpine environments. Perspect Plant Ecol Evol Syst. 2012;14: 363–372.

33. le Roux PC, McGeoch MA. Interaction intensity and importance along two stress gradients: Adding shape to the stress-gradient hypothesis. Oecologia. 2010;162: 733–745. doi: 10.1007/s00442-009-1484-9 19902260

34. Pugnaire FI, Armas C, Valladares F. Soil as a mediator in plant‐plant interactions in a semi‐arid community. J Veg Sci. 2004;15: 85–92.

35. Badano EI, Marquet PA. Biogenic habitat creation affects biomass–diversity relationships in plant communities. Perspect Plant Ecol Evol Syst. 2009;11: 191–201.

36. Sklenář P. Presence of cushion plants increases community diversity in the high equatorial Andes. Flora Morphol Distrib Funct Ecol Plants. 2009;204: 270–277. doi: 10.1016/j.flora.2008.04.001

37. Badano EI, Marquet PA. Biogenic habitat creation affects biomass–diversity relationships in plant communities. Perspect Plant Ecol, Evol Syst. 2009;11: 191–201. doi: 10.1016/j.ppees.2009.03.002

38. Filazzola A, Lortie CJ. A systematic review and conceptual framework for the mechanistic pathways of nurse plants. Glob Ecol Biogeogr. 2014;23: 1335–1345. doi: 10.1111/geb.12202

39. Sydney Council. Green roof design resource manual. 2014. Available:

40. Gregorich EG, Carter MR. Soil sampling and methods of analysis. CRC press; 2007.

41. Kaspar TC, Bland WL. Soil temperature and root growth. Soil Sci. 1992;154: 290–299.

42. Brown C, Lundholm J. Microclimate and substrate depth influence green roof plant community dynamics. Landsc Urban Plan. 2015;143: 134–142. doi: 10.1016/j.landurbplan.2015.07.009

43. Getter KL, Bradley Rowe D, Cregg BM. Solar radiation intensity influences extensive green roof plant communities. Urban For Urban Green. 2009;8: 269–281. doi: 10.1016/j.ufug.2009.06.005

44. Tyystjärvi E. Photoinhibition of photosystem II. International review of cell and molecular biology. Elsevier; 2013. pp. 243–303. doi: 10.1016/B978-0-12-405210-9.00007-2 23273864

45. Murata N, Takahashi S, Nishiyama Y, Allakhverdiev SI. Photoinhibition of photosystem II under environmental stress. Biochim Biophys Acta (BBA)-Bioenergetics. 2007;1767: 414–421. doi: 10.1016/j.bbabio.2006.11.019 17207454

46. Demmig-Adams B, Adams WW. Photoprotection and Other Responses of Plants to High Light Stress. Annu Rev Plant Physiol Plant Mol Biol. 2003;43: 599–626. doi: 10.1146/annurev.pp.43.060192.003123

47. Zandalinas SI, Mittler R, Balfagón D, Arbona V, Gómez-Cadenas A. Plant adaptations to the combination of drought and high temperatures. Physiol Plant. 2018;162: 2–12. doi: 10.1111/ppl.12540 28042678

48. Roig-Villanova I, Martínez-García JF. Plant responses to vegetation proximity: a whole life avoiding shade. Front Plant Sci. 2016;7: 236. doi: 10.3389/fpls.2016.00236 26973679

49. Wright A, Schnitzer SA, Reich PB. Daily environmental conditions determine the competition-facilitation balance for plant water status. J Ecol. 2015;103: 648–656. doi: 10.1111/1365-2745.12397

50. Fujita T, Yamashina C. Do consumer-mediated negative effects on plant establishment outweigh the positive effects of a nurse plant? Ecol Evol. 2018;8: 3702–3710. doi: 10.1002/ece3.3935 29686851

51. Holmgren M, Scheffer M, Huston MA. THE INTERPLAY OF FACILITATION AND COMPETITION IN PLANT COMMUNITIES\rdoi:10.1890/0012-9658(1997)078[1966:TIOFAC]2.0.CO;2. Ecology. 1997;78: 1966–1975. doi: 10.1890/0012-9658(1997)078[1966:TIOFAC]2.0.CO;2

52. Van Noordwijk M, Lawson G, Hairiah K, Wilson J. Root distribution of trees and crops: competition and/or complementarity. Tree–Crop Interact Agrofor a Chang Clim CABI, Wallingford, UK. 2015; 221–257.

53. Lanfranco L, Fiorilli V, Gutjahr C. Partner communication and role of nutrients in the arbuscular mycorrhizal symbiosis. New Phytol. 2018. doi: 10.1111/nph.15230 29806959

54. Montesinos-Navarro A, Valiente-Banuet A, Verdú M. Mycorrhizal symbiosis increases the benefits of plant facilitative interactions. Ecography (Cop). 2018; 1–9. doi: 10.1111/ecog.03926

55. He XH, Critchley C, Bledsoe C. Nitrogen transfer within and between plants through common mycorrhizal networks (CMNs). CRC Crit Rev Plant Sci. 2003;22: 531–567. doi: 10.1080/713608315

56. Walder F, Niemann H, Natarajan M, Lehmann MF, Boller T, Wiemken A. Mycorrhizal Networks: Common Goods of Plants Shared under Unequal Terms of Trade. Plant Physiol. 2012;159: 789–797. doi: 10.1104/pp.112.195727 22517410

57. Montesinos-Navarro A, Verdú M, Querejeta JI, Valiente-Banuet A. Nurse plants transfer more nitrogen to distantly related species. Ecology. 2017;98: 1300–1310. doi: 10.1002/ecy.1771 28188633

58. French K, Robinson SA, Smith LB, Watts EM. Facilitation, competition and parasitic facilitation amongst invasive and native liana seedlings and a native tree seedling. 2017.

Článek vyšel v časopise


2019 Číslo 11