Conceptualising the Global Forest Response to Liana Proliferation

Abstract

Lianas are woody vines, rooted in the soil, and supported physically by trees. Lianas contribute to forest ecosystem functioning globally, but especially in the tropics and subtropics. However, prolific liana growth following heavy disturbance frequently affects subsequent recovery of forest tree diversity, biomass, structure, and function. Understanding this forest liana dynamic, and its sensitivity to climate and anthropogenic forces, is essential for worldwide forest restoration and climate change mitigation. Here, we synthesise the evidence for both positive and negative effects of lianas on forests and propose a framework that outlines the expected global response of forests to disturbance-induced liana proliferation. Emerging evidence suggests that lianas play a major role in both facilitating and delaying forest recovery following disturbance. At low levels of disturbance and/or where environmental conditions favour tree growth, lianas can facilitate forest recovery by protecting trees from extreme weather, fire, weed invasion and herbivory. However, under conditions where lianas proliferate beyond critical thresholds, positive feedbacks are expected to induce and sustain liana-dominated forest states that can endure for decades or even longer. We conceptualise alternative classes of forest recovery response to disturbance and describe measurement and modelling of liana thresholds. We identify four essential challenges for global change science relating to lianas: (1) incorporation of lianas and sapling stems into forest monitoring and tree stand measurements worldwide; (2) long-term experiments to determine variation in liana-tree competition, and potential drivers across forest successional gradients; (3) identification and prediction of liana thresholds and other alternative forest recovery response classes; and (4) dynamic mechanistic modelling of forest recovery to determine regional and global variation within and among different recovery response classes, in relation to variation in potential drivers, liana feedbacks and their interactions. Addressing these challenges will determine the importance of lianas in shaping regional and global forest composition, recovery and dynamics.

Late Pleistocene and Holocene Afromontane vegetation and headwater wetland dynamics within the Eastern Mau Forest, Kenya

“…Despite the net loss in forest cover, some cropland and grassland areas have converted back to forest (Odawa and Seo, 2019). Natural regeneration coupled with reforestation and conservation efforts can be applied to curb and even reverse the impacts of forest loss (Marshall et al, 2020). Thus, the Mau forest management efforts need to consider the impacts of forest activities not only on the forest ecosystem, the interactions of local populations with this, and wider hydrological issues across the basins at national and regional levels.…”

Lianas Significantly Reduce Aboveground and Belowground Carbon Storage: A Virtual Removal Experiment

“…Such a validated model may allow prediction of the impact of liana infestation at large scale, or identification of the change of forest recovery potential due to lianas in secondary forests. In the future, especially when data from more sites is available, this model could also help to disentangle true liana feedback from driver-controlled thresholds, and parasitoid from bandage effects (Marshall et al, 2020).…”

“…Dynamic mechanistic modeling of liana-tree interactions has been recently identified as one of the four essential challenges for global change science relating to lianas (Marshall et al, 2020). Process-based vegetation models may mediate the logistical challenges of conducting liana removal experiments in-situ by extending their findings to exhaustively describe forest biogeochemical cycles, including these occurring belowground (Fisher et al, 2018).…”

“…Process-based vegetation models may mediate the logistical challenges of conducting liana removal experiments in-situ by extending their findings to exhaustively describe forest biogeochemical cycles, including these occurring belowground (Fisher et al, 2018). They can specifically help to predict the forest recovery response after a liana infestation or a liana removal experiment and the underlying response mechanisms (Marshall et al, 2020). Vegetation models can also serve as platforms to integrate trait measurements and/or observed impacts of an experimental design (Dietze and Latimer, 2011).…”

Serviços ecossistêmicos de carbono, composição e estrutura florestal em uma cronosequência de plantios de restauração

“…These results corroborate the need for efforts aiming at the production of seedlings of nontree life forms in the nurseries and their use in restoration projects , which would assist achieving the ecological principles that drive restoration success . Despite this, we must pay attention to the presence of lianas or palms presenting invasive behavior on the restoration sites, which can negatively affect the successional progress (Dislich et al, 2002;Christianini, 2006;Cardinelli et al, 2017;Marshall et al, 2020). Thus, the ecological knowledge related to these species is of utmost importance to define when and how to introduce them into restoration plantings, avoiding undesirable consequences at both short and long term.…”