000			03016nab a2200325 a 4500
003			AR-ReUNN
005			20260702003056.0
008			260630s2006 ag |||||||||||||||||eng
041	0		_aeng
100	1		_aBechara, José Alfredo _96469
245	1	4	_aThe relative importance of water quality, sediment composition and floating vegetation in explaining the macrobenthic community structure of floodplain lakes (Paranán River, Argentina) / José A. Bechara
264		1	_c2006
300			_a15 páginas
500			_aDisponible en caja 16a no 166 de INICNE
520			_aThe bottom macroinvertebrates of three floodplain lakes were sampled during a period of 15 months to evaluate the relative importance of water quality and sediment-vegetation variables in explaining patterns of variation in community structure. Water quality variables were associated with hydrological and climatic cycles, while sediment-vegetation variables were related to local environmental conditions. The relative weights of both sets of variables were measured by performing several Partial Canonical Correspondence Analyses (PCCA), followed by a variance partitioning technique. In all lakes, the greatest macrobenthic biomass was observed during the low water phase. During that period, Chironomus and burrowing may flies (Campsurus) were dominants in a lake having 60% cover of Eichhornia crassipes whereas sphaeriid clams (Pisidium and Eupera), burrowing mayflies, and gastropods (Littoridina) were more abundant in a lake without floating plants. A lake completely covered with E. crassipes had the lowest mean biomass. Biomass decreased sharply during the high water period, and community structure became similar in all lakes, with dominance of Oligochaeta and Ostracoda. The most relevant environmental variables associated with spatial and temporal variations were dissolved oxygen, calcium, clay, floating vegetation, and bottom organic matter. Environmental variables explained about 74% of total variance in community structure, with similar relative contributions of physical and chemical variables of the water (16%), and substrate-vegetation variables (14%). Both sets of variables shared 44% of the explained variance. These results suggest that in the studied lakes, the flood is the major 'batch' process affecting macrobenthos, mainly through changes in water quality. However, local environmental conditions may be as important as water quality in explaining among-lakes variations in macrobenthos at low water periods.
650		4	_aIctiología _99239
650		4	_aIchthyology _9119207
650		4	_aPeces de Agua Dulce _96471
650		4	_aFreshwater Fish _9117439
650		4	_aInland Waters _9117440
650		4	_aRio Parana _910033
650		4	_aPlantas Acuaticas _96318
650		4	_aSedimento _9126005
650		4	_aSediments _9147158
650		4	_aArgentina _94258
773	0		_tHydrobiología _x0018-8158 _gv. 333 n. 2 (1996) _w234475
942			_cART
035			_a(INICN)35615
001			234680
999			_c234680 _d234680
040			_aAR-ReUNN _bspa _cAR-ReUNN _eaacr2