Species composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forests

Abstract

Abstract. Rising temperatures due to climate change influence the wood production of forests. Observations show that some temperate forests increase their productivity, whereas others reduce their productivity. This study focuses on how species composition and forest structure properties influence the temperature sensitivity of aboveground wood production (AWP). It further investigates which forests will increase their productivity the most with rising temperatures. We described forest structure by leaf area index, forest height and tree height heterogeneity. Species composition was described by a functional diversity index (Rao's Q) and a species distribution index ( AWP ). AWP quantified how well species are distributed over the different forest layers with regard to AWP. We analysed 370 170 forest stands generated with a forest gap model. These forest stands covered a wide range of possible forest types. For each stand, we estimated annual aboveground wood production and performed a climate sensitivity analysis based on 320 different climate time series (of 1-year length). The scenarios differed in mean annual temperature and annual temperature amplitude. Temperature sensitivity of wood production was quantified as the relative change in productivity resulting from a 1 • C rise in mean annual temperature or annual temperature amplitude. Increasing AWP positively influenced both temperature sensitivity indices of forest, whereas forest height showed a bell-shaped relationship with both indices. Further, we found forests in each successional stage that are positively affected by temperature rise. For such forests, large AWP values were important. In the case of young forests, low functional diversity and small tree height heterogeneity were associated with a positive effect of temperature on wood production. During later successional stages, higher species diversity and larger tree height heterogeneity were an advantage. To achieve such a development, one could plant below the closed canopy of even-aged, pioneer trees a climax-species-rich understorey that will build the canopy of the mature forest. This study highlights that forest structure and species composition are both relevant for understanding the temperature sensitivity of wood production.

Tackling unresolved questions in forest ecology: The past and future role of simulation models

“…However, stand-scale models, such as individual-based gap models, have also been used to explore forest dynamics under climate-change scenarios (Bugmann & Fischlin, 1996;Collalti et al, 2018;Fischer et al, 2014;Pastor & Post, 1986;Reyer, 2015;Shugart et al, 2018). Such finer-scale models can further inform the role of forest composition and structure in shaping forest responses to environmental drivers (Bohn et al, 2018;Fyllas et al, 2017). Additionally, SDMs have been used…”

Analyzing the effect of silvicultural management on the trade-off between stand structural heterogeneity and productivity over time

“…Sustainably maintaining multifunctional forest ecosystems has become a widespread objective of forest management (Manning et al 2018;Schmithüsen 2008). This development increases the interest in analyzing the potentially strong influence of tree species diversity (Paquette and Messier 2011;Gamfeldt et al 2013;Liang et al 2016) and forest structure on ecosystem functions and services (Felipe-Lucia et al 2018;Bohn et al 2018;Bohn and Huth 2017). Previously established monospecific and even-aged forests had the aim of a high yield and the homogeneous provision of a narrow range of predominant products, which were produced with the aim to provide a homogeneous product quality (Puettmann et al 2015).…”

Stand Structure and Local Landscape Variables Are the Dominant Factors Explaining Shrub and Tree Diversity in Mediterranean Forests

“…Previous studies have shown the connection between forest structure and plant diversity, which we also wanted to test, and how it is linked to variables such as diameter size distribution, heights, basal area, wood stock, vegetation cover in different layers of the forest (vertical structure [24]), or tree density and age [25][26][27], all of which are modifiable by management [28]. Management directed at changing stand structure variables can significantly affect plant diversity in the understory by altering environmental factors such as light and water availability [29][30][31][32][33][34]. Nevertheless, factors other than forest structure, such as soil characteristics or stage of development (crop age [24]) can influence plant community composition and diversity.…”