Demistifying canopy-water interactions in a tropical montane cloud forest: including bark traits into rain-fog-stemflow interactions

• Grant number: 21/11697-9
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2022
• End date: October 31, 2024
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Kelly Cristina Tonello
• Grantee: Kelly Cristina Tonello
• Host Institution: Centro de Ciências e Tecnologias para a Sustentabilidade (CCTS). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil
• Associated researchers: Andrés Gabriel Arguedas Chaverri ; Anna Ilek ; Aparecido Junior de Menezes ; John Toland Van Stan II ; Kathrin Rousk ; Sérgio Dias Campos
• Associated scholarship(s): 22/13033-3 - Relationships between bark properties and stemflow yield: an analysis from wettability, BP.TT; 22/05941-7 - Relationships between bark properties and stemflow yield: an analysis from wettability, BP.TT

Abstract

A little researched, but relevant part of the forest water balance is the partition of rainfall through the tree crowns. When rain comes into contact with the tree tops, some of it returns to the atmosphere, another drips through cracks or drains down the tree trunk (stemflow, SF). The SF is particularly under-researched, despite its potential to concentrate rainfall inflows into small areas (1-10m²tree-¹), which can, in turn, preferentially infiltrate along the root system and contribute to water recharge underground. In cloudy forests, in addition to rain, hidden precipitation (fog) is a common hydrological variable, and despite its frequent occurrence and the fact that it is undoubtedly an water input into the system, it is unknown and unaccounted for. When interacting with the forest, mist droplets can reach the soil surface even in the absence of rain: in this case, the SF can be particularly voluminous, contributing even more to the annual precipitation. In turn, throughout this process, the bark structure is a master variable, as it has persistent contact with the SF during drainage. Therefore, the main question that arises is: What is the fog contribution to the forest water balance? Are we deficient in calculating the water balance, since the weather stations actually only record rainfall? Since the bark is an area of fog deposition, how does it relate to SF during fog events? Cloud forests occur in specific places in Brazil and in this proposal, the research will be conducted in Serra do Mar State Park (PESM-Cunha). To answer these questions, rainfall and fog will be monitored and, simultaneously, the SF variability in defined plots. In these, the trees will be classified into classes of diameter at breast height, crown geometry, texture and bark wettability. Climatic data will be confronted with the SF dynamics and the tree structure. It should be noted that SF has rarely been examined in Montana Rainforests and not only that, but this investigation is also the first to examine how bark wettability correlates with stemflow in Montana Rainforests at Serra do Mar under fog events. This proposal on the variability of the SF and the structural characteristics of the trees that drive it can fill an important gap in knowledge about the components of the water balance in this environment. This proposal is a world pioneer, associating unique environments and the application of techniques hitherto never applied in Forest Hydrology. (AU)