Drainage effects on leaf traits of trees in tropical peat swamp forests in Central Kalimantan, Indonesia

Abstract

Large areas of the tropical peat swamp forests in Central Kalimantan were drained to be converted into rice fields and then abandoned. A change in the soil water level due to drainage in the forests must have had a big impact on the ecology and ecophysiology of the trees in the drained remnant forests. The leaf traits of these trees in particular may have been directly or indirectly affected by drainage because of their high sensitivity to environmental change. To understand the influence of drainage on leaf traits, we investigated leaf morphological and physiological differences between intact and drained peat swamp forests in Palangka Raya, Indonesia, using 14 species distributed over both types of forests. We compared the leaf mass per unit area (LMA), leaf toughness, leaf area-and mass-based nitrogen content (N area and N mass), carbon/nitrogen ratio, total phenolics, condensed tannin and lignin content and carbon isotope ratio (13 C) of both types of forest trees. In the drained forest, trees had higher values in LMA, N area , and 13 C than in the intact forest, suggesting that such trees adjust themselves to dry conditions to increase photosynthetic ability with high water use efficiency compared with those in intact forests. We also found an increase in condensed tannin content in drained forest trees, which may offset the drainage-induced acceleration of leaf decomposition to some extent.

Leaf toughness increases with tree height and is associated with internal leaf structure and photosynthetic traits in a tropical rain forest

“…In this study, the thicker and higher-LMA leaves observed in both the heterobaric and homobaric species in the upper canopy protect against heat and drought conditions in the forest canopy, consistent with previous studies (Niinemets, 2007;Leigh et al, 2012;Kenzo et al, 2015;Ichie et al, 2019). Furthermore, we found that the increases in thickness and LMA contributed to increased leaf toughness with tree height.…”

Leaf Litter Decomposition and Nutrient Release of Three Native Tree Species in a Drained Tropical Peatland in Riau, Indonesia

“…Total K and P in the litter of all NS were higher than those in litter of Koompassia malaccensis, Shorea uliginosa, and mixed tropical peat forest tree species (Sulistiyanto et al 2005;Ong et al 2017). However, leaf litter of all NS in present study in general had lower N content than that in most of native species of tropical peat swamp forest, despite its value was in the range (0.8-1.78) (Sulistiyanto et al 2005;Ong et al 2017;Ichie et al 2019) Lignin content in the litter of all NS in present study (36.1-39.2%) was higher than that in the range of content lignin in other native tree species of peat swamp forest (3.8-35.8%) (Hoyos-Santillan et al 2015;Ichie et al 2019) also than that in the average of broadleaves (29.26%) and coniferous (21.57%) (Rahman et al 2013). In different ecosystem with wider scale, lignin content of leaf litter of beech (36%) in temperate forest were the closest to lignin content in the NS (Kara et al 2014).…”

Artificial shade shelters mitigate harsh microclimate conditions and enhance growth in tropical tree seedlings planted in degraded land

“…The increased LMA under the open control observed in this study may also have contributed to increased drought tolerance (Kramer 1983;Niinemets 2001). For example, leaves with a high LMA showed higher tolerance to dehydration in a study using dipterocarp species in Malaysia (Kenzo et al 2007), and trees subjected to drought stress using an artificial drain had a significantly larger LMA than those in wet plots in an Indonesian tropical swamp forest (Ichie et al 2019). A large LMA contributes to drought tolerance by increasing the strength of a leaf, because greater physical strength and a thick cell wall promote tolerance of the lower leaf water potential associated with drought stress (Niinemets 2001;Koch et al 2004;Poorter et al 2009).…”