Resprouting and foliar functional traits driving the invasiveness of Eriobotrya japonica in a secondary cloud forest

Abstract

Resprouting of non-native tree invaders is a threat to tropical montane cloud forests and particularly to periurban forests. Resprouting is a common response of trees to disturbance in many ecosystems; however, little is known about the resprouting of woody exotic species with shade-tolerant characteristics that can slowly invade those forests. Furthermore, resprouting of woody invaders is a complex challenge for the control of invasive species since it is a major driver of reinvasion and persistence. In this study, we focus on the resprouting ability of a potential invader, Eriobotrya japonica, in a periurban cloud forest reserve of Xalapa, Mexico. We experimentally cut trees and juveniles in the secondary forest and clipped seedlings at the forest edge, and assessed resprout number, dimensions, emergence position, survival, and leaves per resprout. We then determined foliar traits of the newly produced leaves (leaf area (LA), specific leaf area (SLA), leaf mass area (LMA), leaf dry mass content (LDMC), and thickness). Our results show that resprouting occurred within a month in both tree stumps and clipped seedlings. Resprout survival was 50-80% in stumps, and 63-88% in clipped seedlings. Resprouts were produced mostly in the upper 5 cm below the cut. Leaf number was positively related to dimensions of the longest resprout. Some leaf traits of E. japonica were similar to those of shade-tolerant trees, but there is a combination of strategies since the species presents higher LA and thicker leaves than other native tree species, yet its LMA and LDMC are within the range presented by shade-tolerant species. Eriobotrya japonica is a woody invasive that partly behaves as a shade-tolerant tree and resprouts profusely and rapidly from stumps and clipped seedlings. Its resprouting ability is therefore a key trait by which to explain the invasive potential of this woody species.