Massive tree mortality from flood pulse disturbances in Amazonian floodplain forests: The collateral effects of hydropower production

2019 ◽  
Vol 659 ◽  
pp. 587-598 ◽  
Author(s):  
Angélica Faria de Resende ◽  
Jochen Schöngart ◽  
Annia Susin Streher ◽  
Jefferson Ferreira-Ferreira ◽  
Maria Teresa Fernandez Piedade ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Flood Pulse ◽  
Floodplain Forests ◽  
Collateral Effects ◽  
Hydropower Production ◽  
Massive Tree

Leaf decomposition and fine fuels in floodplain forests of the Rio Negro in the Brazilian Amazon

2013 ◽  
Vol 29 (5) ◽  
pp. 455-458 ◽  
Author(s):  
Aline Ramos dos Santos ◽  
Bruce Walker Nelson
Keyword(s):  
Tree Mortality ◽  
Brazilian Amazon ◽  
Leaf Decomposition ◽  
Fire Intensity ◽  
Floodplain Forests ◽  
Tree Roots ◽  
Upland Forest ◽  
Black Water ◽  
Rio Negro ◽  
Forest Sites

Abstract:Despite being inundated for up to 9 mo of the year, black-water floodplain forests in the Brazilian Amazon are susceptible to fire. Post-fire tree mortality is higher and fire spreads further in the floodplain, compared with adjacent upland forest. To understand these differences between the two forest types, we compared how leaf decomposition and fine-fuel loads change with inundation and soil texture. Litterbags containing leaves of Clitoria fairchildiana were placed on upland forest floor and submerged at two depths in a backwater of the Rio Negro. We used 80 bags per treatment and retrieved subsets every ~16 d from which the contents were cleaned, dried, weighed and discarded. Over the 81-d experiment, upland leaves decomposed two to three times faster than submerged leaves. Fine-fuel biomass (litter + root mat) was measured at 28 upland forest sites and 29 floodplain forest sites of the middle Rio Negro. Floodplain forests held about twice the fine fuel (25.9 ± 10.6 Mg ha−1) of uplands (10.9 ± 2.3 Mg ha−1). Upland soils had more sand but a carpet of fine apogeotropic tree roots was more common and thicker in floodplains. We infer that slow decomposition of submerged leaves leads to high tree mortality from fire in black-water floodplains by (1) increasing fire intensity due to high fine-litter fuel load and (2) making tree roots more vulnerable to burning because they form a peat-like mat to absorb nutrients from the thick litter.

The influence of climate on pool inception in boreal fens

Botany ◽  
2015 ◽  
Vol 93 (10) ◽  
pp. 637-649 ◽  
Author(s):  
Yann Arlen-Pouliot ◽  
Serge Payette
Keyword(s):  
Vegetation Cover ◽  
Little Ice Age ◽  
Tree Mortality ◽  
Ice Age ◽  
Climatic Forcing ◽  
Influence Of Water ◽  
Physical Degradation ◽  
Pool Formation ◽  
Massive Tree

Fens are one of the two most important peatland types of the boreal biome. The fen surface is often made of contrasted microenvironments, pools and strings, distributed in a geometric arrangement known as patterned fen. The fens are under the influence of varying water regimes causing the formation of pools, a process that we named aqualysis. The term refers to the physical degradation of the vegetation cover under the influence of water ponding. It is proposed here that pool inception is among a set of differential responses of peatland ecosystems to changes in hydrology caused by climate. In this study, we have evaluated the influence of climate on pool inception using the spatiotemporal distribution of trees found dead in pools of four boreal fens of northwestern Quebec. Tree-ring dating of tree mortality allowed the determination of the most recent and synchronized periods of pool formation in the studied fens. Most trees died over the last centuries, particularly after 1750 AD. The demographic pattern of tree establishment and mortality highlights a climatic forcing linked to the Little Ice Age oscillation opposing less humid events facilitating tree colonization succeeded by more humid events causing massive tree death and pool inception. We conclude that peatland aqualysis is among the processes controlled by climate contributing to the dynamics of patterned fens through pool formation.

scholarly journals Flood-pulse disturbances as a threat for long-living Amazonian trees

2019 ◽  
Author(s):  
Angélica F Resende ◽  
Maria T F Piedade ◽  
Yuri O Feitosa ◽  
Victor Hugo F Andrade ◽  
Susan E Trumbore ◽  
...  
Keyword(s):  
Tree Species ◽  
Tree Mortality ◽  
Hydroelectric Plant ◽  
Structural Parameters ◽  
Anthropogenic Disturbances ◽  
Passage Time ◽  
Flood Pulse ◽  
Water Levels ◽  
Living Tree ◽  
Diameter Increment

AbstractThe long-living tree species Eschweilera tenuifolia (O. Berg) Miers (Lecythidaceae) is characteristic to oligotrophic floodplain forests (igapó) influenced by a regular and predictable flood-pulse. This species preferentially occurs at macrohabitats flooded up to 10 months per year forming monodominant stands. We aimed to analyze the growth and mortality patterns of this species under pristine conditions (Jaú National Park-JNP) and in an impacted igapó (Uatumã Sustainable Development Reserve-USDR) where the downstream flood-pulse disturbance occasioned by the Balbina hydroelectric plant caused massive mortality of this species. Using a total of 91 trees (62 living and 29 dead) at the USDR and 52 (31 living and 21 dead) from JNP, we analyzed age-diameter relationships, mean passage time through 5-cm diameter classes, growth change patterns, growth ratios, clustering of mean diameter increment (MDI), and dated the year of death from each individual using radiocarbon (14C) analysis. Growth and mortality patterns were then related to climatic or anthropogenic disturbances. Our results show similar structural parameters for both studied populations regarding the estimated maximum ages of 466 years (JNP) and 498 years (USDR) and MDI, except for one single tree at the USDR with an estimated age of 820 yrs. Living trees from JNP showed distinctly altered growth after 1975, probably related to consecutive years of high annual minimum water levels. Tree mortality in the JNP occurred during different periods, probably induced by extreme hydroclimatic events. At the USDR changes in growth and mortality patterns occurred after 1983, when the Balbina dam construction started. Despite being one of the best flood-adapted tree species, E. tenuifolia seems to be sensitive to both, long-lasting dry and wet periods induced by climatic or anthropogenic disturbances or resulting synergies among both. Even more than 30 years after the start of disturbances at the USDR, the flood-pulse alteration continues affecting both mortality and growth of this species which can potentially cause regional extinction.

On syntaxonomy of floodplain forests (Salicetea purpureae Moor 1958) of the Irtysh and Black Irtysh rivers

2005 ◽  
pp. 82-92
Author(s):  
G. S. Taran
Keyword(s):  
Populus Alba ◽  
Floodplain Forests ◽  
White Poplar ◽  
Salix Alba ◽  
River Floodplain ◽  
White Willow ◽  
Irtysh River

The paper characterizes poplar (Populus alba, P. nig­ra) and white willow (Salix alba) forests of the Irtysh and the Black Irtysh river floodplain, together with the silvery salt tree (Halimodendron halodendron) community of the Black Irtysh river floodplain. The Black Irtysh floodplain willow and poplar forests are separated into a new alliance, Rubio dolichophyllae—Populion albae Taran all. nov. (Salicetalia purpureae Moor 1958, Salicetea purpureae Moor 1958), which includes the associations Rubio dolichophyllae—Popu­letum albae Taran 1997 and Rubio dolichophyllae—Salicetum albae Taran ass. nov. The Halimodendron halodendron community is probably related to the class Nerio-Tamaricetea Br.-Bl. et de Bolós 1958. White poplar forests in the Irtysh R. upper reaches, described within the Semipalatinsk city limits, belong to the association Heracleo dissecti—Populetum albae Taran 1997 and its subassociation H. d. —P. a. lamietosum albi Taran 1997 (Equiseto hyemalis—Populion nigrae Taran 1997, Salicetalia purpureae Moor 1958).

Large-scale vegetation mapping of the Pinega river valley (the surroundings of Golubino village, Arkhangelsk oblast)

2018 ◽  
pp. 19-39
Author(s):  
M. A. Makarova
Keyword(s):  
Plant Communities ◽  
Indicator Species ◽  
Dominant Species ◽  
Large Scale ◽  
Vegetation Mapping ◽  
River Valley ◽  
Floodplain Forests ◽  
Floodplain Vegetation ◽  
Wet Meadows ◽  
Arkhangelsk Oblast

Geobotanical survey of floodplain natural complexes near gypsum outcrops in the Pinega river valley was done in 2015. Large-scale geobotanical map of the key polygon (scale 1 : 30 000) was composed. Typological units of vegetation were selected on the basis of the composition of dominant species and groups of indicator species. Homogeneous and heterogeneous territorial units of vegetation (serial series, combinations, environmental series) were used. 53 mapped unit types (25 homogeneous types and 28 heterogeneous types) were recognized. The floodplain vegetation consists of 17 homogeneous types of plant communities, 3 series, 14 combinations and 6 ecological series. The sites of old floodplain forests, such as willow forests with Urtica sondenii rare in the Arkhangelsk region and oxbow wet meadows with Scolochloa festucacea were identified.

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