Effect of succession gaps on the understory water-holding capacity in an over-mature alpine forest at the upper reaches of the Yangtze River

Abstract

Abstract:The water-holding capacity (WHC) of the understory in the headwater regions of major rivers plays an important role in both the capacity of the forest water reservoir and water quality and quantity in the butted rivers. Although forest gaps could regulate water-holding patterns in the understory by redistributing coarse woody debris (CWD), fine woody debris (FWD), non-woody debris (NWD) and understory vegetation, little information is available on the effects of forest gaps on understory WHC. Therefore, we investigated the WHCs of CWD, FWD, NWD, herbaceous vegetation, mosses, epiphytes (including fern and lichen growing on the surface of logs) and soils from the gap centre to the adjacent closed canopy in an alpine forest at the upper reaches of the Yangtze River. The total WHC of the alpine forest understory components was approximately 300 mm. Soil layer had the largest contribution to the total understory WHC (90%), and among the aboveground components, CWD and mosses contributed 5% and 4% to the aboveground WHC, respectively. With the exception of that of the herbaceous layer, the WHC of the forest floor increased from the gap centre to the closed canopy. Although mosses had the lowest biomass allocation on the alpine forest floor, the waterholding ratio (k) of mosses reached 485%. In conclusion, biomass is the parameter that most strongly and positively correlated with the WHC of the alpine forest understory, and forest gap formation decreases the understory WHC of alpine forest resulting from a decrease in organic soils, CWDs and mosses. Copyright © 2015 John Wiley & Sons, Ltd. Highlights• The effects of gaps on the understory WHC were examined in an alpine forest.• Gaps decreased the understory WHC by decreasing the amounts of the larger WHC components.• The contribution of CWD and mosses to the aboveground WHC was large.• The WHC of dead debris was higher than that of the vegetation.

Rainfall interception and redistribution by a common North American understory and pasture forb, <i>Eupatorium capillifolium</i> (Lam. dogfennel)

“…Methodological limitations withstanding, the S U estimates in this study fit within the range of water storage capacities of other herbaceous plants synthesized by Breuer et al (2003). This synthesis is focused on the leaves of herbaceous plants (alongside other plant types) (Breuer et al, 2003), but less research has estimated the stem component (or reported a total including the stem component) of the water storage capacity for short vegetation (Bradley et al, 2003;Wang et al, 2016;Wohlfahrt et al, 2006;Yu et al, 2012). The stems of herbaceous plants, even thick smooth stems (> 1 cm in diameter) can store nearly 0.5 mm, e.g., Taraxacum officinale (dandelion) (Wohlfahrt et al, 2006).…”

The microbial community in decaying fallen logs varies with critical period in an alpine forest

“…The alpine forest located in the upper reaches of the Yangtze River and the eastern Qinghai-Tibet Plateau plays important roles in holding fresh water, sequestering carbon and indicating climate change [ 19 , 20 ]. Previous studies have indicated that fallen logs with different decay classes account for 53.00 t·ha -1 in the primary Minjiang fir ( Abies faxoniana ) forest ecosystem [ 21 ] and play crucial roles in nurturing biodiversity, maintaining site productivity and holding water [ 22 ]. However, the changes that occur in the microbial community in different decay classes of fallen logs with critical periods remain unknown.…”

Water, Rather than Temperature, Dominantly Impacts How Soil Fauna Affect Dissolved Carbon and Nitrogen Release from Fresh Litter during Early Litter Decomposition

“…Faunal abundance varies between seasons with changes in temperature and rainfall [20,21]; moreover, hydrological leaching that contributes to DOC and TDN release normally occurs during the growing season [22,23]. Whether the faunal effect interacts with this process is unclear.…”