<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wick, B.</style></author><author><style face="normal" font="default" size="100%">Tiessen, H.</style></author><author><style face="normal" font="default" size="100%">Menezes, R. S. C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Land quality changes following the conversion of the natural vegetation into silvo-pastoral systems in semi-arid NE Brazil</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">agroforestry</style></keyword><keyword><style  face="normal" font="default" size="100%">deforestation</style></keyword><keyword><style  face="normal" font="default" size="100%">dynamics</style></keyword><keyword><style  face="normal" font="default" size="100%">indigenous trees</style></keyword><keyword><style  face="normal" font="default" size="100%">land quality change</style></keyword><keyword><style  face="normal" font="default" size="100%">microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">northeastern brazil</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient</style></keyword><keyword><style  face="normal" font="default" size="100%">organic-carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">pasture</style></keyword><keyword><style  face="normal" font="default" size="100%">savanna</style></keyword><keyword><style  face="normal" font="default" size="100%">silvo-pastoral systems</style></keyword><keyword><style  face="normal" font="default" size="100%">soil enzymes</style></keyword><keyword><style  face="normal" font="default" size="100%">soil microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">trees</style></keyword><keyword><style  face="normal" font="default" size="100%">tropical deciduous forest</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://000088041000006</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">222</style></volume><pages><style face="normal" font="default" size="100%">59-70</style></pages><isbn><style face="normal" font="default" size="100%">0032-079X</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The presence of trees in grasslands frequently results in resource islands of higher soil quality. Therefore, some native trees are often preserved or agroforestry species are interplanted when land is cleared for pasture. We evaluated soil quality changes associated with the conversion of a native thorn forest (caatinga) into silvo-pastoral systems in semiarid NE Brazil. Soil nutrients, organic matter, microbial biomass and soil enzymes under native caatinga, the canopy of two preserved native (Ziziphus joazeiro and Spondias tuberosa) and one introduced tree species (Prosopis juliflora), and under a planted pasture of Cenchrus ciliaris were compared. The two preserved tree species maintained high nutrient and organic matter contents and high biological activity levels not only relative to the grass but also relative to the native caatinga. The non-deciduous Z. joazeiro was more effective than the deciduous S. tuberosa, and enriched surface soils by 100 mg P kg(-1). The complete replacement of natural caatinga with C. ciliaris pasture or a C. ciliaris-P. juliflora silvopastoral system had, after 14 years, decreased microbial biomass C and N contents, and ss-glucosidase activity, but did not affect soil nutrient or organic matter status. The biological activity under the trees of the tree-grass association was greater than under grass alone, although P. juliflora did not maintain higher nutrient or organic matter levels. The search for indigenous alternatives to the main agroforestry species may provide viable alternatives for improved land management and the conservation of biodiversity. Microbiological and biochemical parameters responded more readily to changes in land management than chemical fertility indices. They are important indices for the impact of vegetation changes and its associated land quality changes.</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><accession-num><style face="normal" font="default" size="100%">ISI:000088041000006</style></accession-num><notes><style face="normal" font="default" size="100%">ISI Document Delivery No.: 331WETimes Cited: 21Cited Reference Count: 51Cited References: *SYSTAT WIND, 1992, STAT VERS 5 ANTONINO MD, 1992, PROSOPIS SPECIES ASP, P43 BABOS K, 1992, ACTA BOT HUNGARICA, V37, P183 BELSKY AJ, 1993, AGROFOREST SYST, V24, P1 BELSKY AJ, 1994, ECOLOGY, V75, P922 BHOJVAID PP, 1998, FOREST ECOL MANAG, V106, P181 BUSCHBACHER R, 1988, J ECOL, V76, P682 CAMPBELL BM, 1994, AGROFOREST SYST, V28, P159 CERRI CC, 1991, FOREST ECOL MANAG, V38, P247 DIAGNE O, 1992, PROSOPIS SPECIES ASP, P47 DIAGNE O, 1994, SOIL BIOL BIOCHEM, V26, P1709 EITEN G, 1992, AN ACAD BRAS CIEN S1, V64, P35 EIVAZI F, 1988, SOIL BIOL BIOCHEM, V20, P601 GARCIAMIRAGAYA J, 1994, ACTA OECOL, V15, P477 GARCIAOLIVA F, 1994, OECOLOGIA, V99, P392 GARCIAOLIVA F, 1999, GEODERMA, V88, P1 GIBSON A, 1992, PROSOPIS SPECIES ASP, P207 HEANES DL, 1984, COMMUN SOIL SCI PLAN, V15, P1191 KELLMAN M, 1979, J ECOL, V67, P565 KIEFT TL, 1994, BIOL FERT SOILS, V18, P155 KNOOP WT, 1985, J ECOL, V73, P235 KOUNO K, 1995, SOIL BIOL BIOCHEM, V27, P1353 LADD JN, 1972, SOIL BIOL BIOCHEM, V4, P19 LEAKEY RRB, 1998, AGROFOREST SYST, V38, P165 MACHADO ICS, 1997, BIOTROPICA, V29, P57 MENEZES RSC, 1999, IN PRESS REV BRAS CI MEREDITH D, 1955, GRASSES PASTURES S A MORSS LR, 1994, RADIOCHIM ACTA, V66, P89 NOELL E, 1995, GENERATIONS, V19, P14 NUNES J, 1990, REV BRAS CI SOLO, V14, P69 NYBERG G, 1995, AGROFOREST SYST, V32, P45 POWLSON DS, 1994, BIOMASS, P3 RAVEH A, 1979, WATER RES, V13, P911 RHOADES CC, 1997, AGROFOREST SYST, V35, P71 SALA OE, 1989, OECOLOGIA, V81, P501 SAMPAIO EVS, 1995, SEASONALLY DRY TROPI, P35 SAUNDERS WMH, 1955, J SOIL SCI, V6, P254 TABATABAI MA, 1969, SOIL BIOL BIOCHEM, V1, P301 THOMAS RL, 1967, AGRON J, V59, P240 TIEDEMANN AR, 1973, SOIL SCI SOC AM J, V37, P107 TIESSEN H, 1992, AGR ECOSYST ENVIRON, V38, P139 TIESSEN H, 1993, SOIL SAMPLING METHOD, P75 TIESSEN H, 1998, CLIMATIC CHANGE, V40, P105 TROUVE C, 1994, SOIL BIOL BIOCHEM, V26, P287 VANCE ED, 1987, SOIL BIOL BIOCHEM, V19, P703 VELDKAMP E, 1994, SOIL SCI SOC AM J, V58, P175 VERINUMBE I, 1993, AGROFOREST SYST, V21, P287 WELTZIN JF, 1990, J VEG SCI, V1, P325 WICK B, 1998, PLANT SOIL, V202, P97 WILSON JR, 1996, AUST J AGR RES, V47, P1075 YOUNG A, 1997, AGROFORESTRY SOIL MA, P23Kluwer academic publDordrecht</style></notes></record></records></xml>