000			047800000a22006490004500
911			_aXL1996500000
901			_aF40
903			_aE
903			_aV
904			_aBCO
905			_aC
906			_a19960101
908			_aJ
909			_aAS
912			_aEn
912			_aEn
914			_aBCO1
914			_aINFOR
914			_aRIBRE
914			_aBN
082	0	4	_a24632
100	1		_988072 _aLugo, A.E.
100	1		_972742 _aGonzález Liboy, J.A.
100	1		_957747 _aCintron, B.
100	1		_963571 _aDugger, K.
260			_c1978
041	0		_aEn
500			_a14 ilus. 10 tab. Sum. (En)
520			_aPlants in the Guánica Forest (lat. 18° N) grew under the following climatic conditions: annual temperature, 25.8°C; annual rainfall, 929 mm; annual pan evaporation, 2074 mm; actual evapotranspiration, 722 mm; yearly runoff, 205 mm; and mean solar radiation, 4366 kcal/m{ostrok}/day. The climate was seasonal with most of the runoff between September and October. Soils normally exhibited water deficits during 10 months of the year. Shallow soils with frequent limestone out-cropping compounded the water-supply problem of plants. Four upland plant associations were studied. The scrub forest had a basal area (BA) of 4.2 m{ostrok}/ha and a complexity index (CI) of 2 calculated for trees with dbh > 5 cm. Its shallow soils were very sandy, or rocky. Succulent plants were common, and the canopy was open. The deciduous forest had a BA of 8 m{ostrok}/ha and a CI of 20. Its soils were deeper, and comprised of 64 percent sand and 33 percent silt. A taller and denser canopy developed in this forest. A mahogany plantation grew in semi-evergreen forest soils. There, soils were as deep as 1 m and rich in clay and silt. An ecotonal forest (between deciduous and semi-evergreen) had a BA of 10.7 m{ostrok}/ha and a CI of 20. The canopy of the ecotonal forest was relatively closed with a leaf area index (LAI) that varied seasonally between 1.2 and 4.2. Plant photosynthesis, respiration, transpiration, litter fall, and loose litter standing crop responded to moisture availability. Net daytime photosynthesis increased linearly with soil moisture availability (r = 0.76) and averaged 2.0 g/m{ostrok} leaf area/day for non-succulent plants. Nighttime respiration rates increased with decreasing soil moisture availability (r = 0.65) and averaged 0.36 g/m{ostrok} leaf area/day for non-succulent plants and 0.1 g/m{ostrok} photosynthetic area/day for succulent plants. Tree trunks respired during the dry season at a rate of 2.64 g/m{ostrok} surface area/day. Soil respiration was 4.74 g/m{ostrok}/day. Transpiration of succulent plants was 64 g H subíndice 2 O/m{ostrok} photosynthetic area/day, while for non-succulent plants it was 576 g H subíndice 2 O/m{ostrok} leaf area/day. Water-use efficiency was 6.2 for succulent plants and 1.8 for non-succulent plants. Succulent plants also exhibited nighttime or 24 hr C-uptake and water loss during early morning or late afternoon. Leaf fall and standing crop of loose litter increased with decreasing soil moisture availability. Mean litter-fall production for the scrub, deciduous forest, and mahogany plantation in g/m{ostrok}/day was: 0.28, 0.79 and 1.48, respectively. Mean litter fall and mean standing crop of loose litter for the forest as a whole were 0.66 g/m{ostrok}/day and 715 g/m{ostrok}, respectively. Mean annual litter turnover was 0.34. Gross primary productivity average 1.6 g/m{ostrok}/day and correlated linearly with soil moisture availability (r = 0.87). It is concluded that soil moisture availability (a function of shallow soils and low rainfall) is the factor that determines forest productivity, growth characteristics, water loss, and physiognomy.
650	1	4	_9139407 _aCARACTERISTICAS DEL SITIO
650	1	4	_9160348 _aPRODUCTIVIDAD
650	1	4	_9146971 _aESTRUCTURA DEL BOSQUE
650	1	4	_9167146 _aTRANSPIRACION
650	1	4	_9145834 _aENERGIA SOLAR
650	1	4	_9165569 _aSUELO
650	1	4	_9151868 _aINTERCAMBIO DE GASES
650	1	4	_9161399 _aPUERTO RICO
691			_9164939 _aSITE FACTORS
691			_9160358 _aPRODUCTIVITY
691			_9341428 _aTRANSPIRATION
691			_9165156 _aSOLAR ENERGY
691			_9165084 _aSOIL
691			_9320346 _aGAS EXCHANGE
691			_9161399 _aPUERTO RICO
692			_aFACTEUR LIE AU SITE
692			_aPRODUCTIVITE
692			_aTRANSPIRATION
692			_aENERGIE SOLAIRE
692			_aSOL
692			_aECHANGE GAZEUX
692			_aPORTO RICO
773	0		_tBiotrópica (EUA) _d1978 _gv. 10(4) p. 278-291
040			_aCR-TuBCO _cCR-TuBCO _bEs
245	1	0	_aStructure, productivity, and transpiration of a subtropical dry forest in Puerto Rico
942			_cANA
003			CR-TuBCO
999			_c57898 _d57898