Testing the importance of a common ectomycorrhizal network for dipterocarp seedling growth and survival in tropical forests of Borneo

Francis Q. Brearley, Philippe Saner, Ayuho Uchida, David F. R. P. Burslem, Andy Hector, Reuben Nilus, Julie D. Scholes, Simon Egli
2016 Plant Ecology & Diversity  
19 Background: Connections between mature trees and seedlings via ectomycorrhizal 20 (EcM) hyphal networks existing in dipterocarp-dominated tropical rain forests of South-21 east Asia could have strong implications for seedling growth and survival and the 22 maintenance of high diversity in such forests. 23 Aim: To test whether EcM hyphal network connections are important for the growth 24 and survival of dipterocarp seedlings. 25 Methods: We conducted four independent experiments that
more » ... iments that prevented contact of 26 experimental seedlings with an EcM network by using a series of fine meshes and/or 27 plastic barriers. We measured the growth and survival (and foliar δ 13 C in one 28 experiment) of seedlings of six dipterocarp species over intervals ranging from 11 to 29 29 months. 30 Results: Seedling growth (diameter, height or leaf number) was unaffected by exclusion 31 from the EcM network in three experiments and there were no differences in foliar δ 13 C 32 values in the fourth. Seedling survival was reduced following exclusion from the EcM 33 network in one experiment. Our results give little support to the hypothesis that 34 dipterocarp seedlings growing in the shaded forest understorey benefit from being 35 connected, through a common EcM network, to surrounding trees. 36 Conclusions: We suggest that our negative results, in contrast to studies conducted in 37 low diversity boreo-temperate or tropical forests, are due to these high diversity forests 38 lacking host species-specific EcM fungi, and therefore providing little opportunity for 39 adaptive support of seedlings via hyphal networks. 40
doi:10.1080/17550874.2017.1283649 fatcat:envkjktiyjbdtmavk2ic5nzqla