Long-term vegetation change in the Succulent Karoo, South Africa following 67 years of rest from grazing

Rahlao, Sebataolo; Hoffman, M. Timm; Todd, Simon; McGrath, Kate

doi:10.1016/j.jaridenv.2007.08.003

Cited by 39 publications

(22 citation statements)

References 22 publications

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“…The fast response of insects to current changes in climate should also be of relevance towards such dynamics. It has been shown in southern Africa that termitaria density is positively correlated with rainfall (Picker et al 2007), futhermore, they may reach more than 20,000 years in age, becoming a stable part of the landscape (Midgley et al 2002) and altering vegetation composition (Rahlao et al 2008). While a potential association between termitaria and woody species distribution in campos de murundus of central Brazil remains to be investigated, there are similar landscapes in Africa and Australian savannas, as well elsewhere in the Neotropics, which may indeed be caused by termite or other biotic-mediated activity (Cox et al 1989;Ellery et al 1998;McCarthy et al 1998;Brossard et al 2007).…”

Section: Discussionmentioning

confidence: 99%

“…This landscape type, with tree-covered mounds in a matrix of floodtolerant grasses, occurs extensively throughout the cerrado ( Fig. 1; Oliveira-Filho and Furley 1990), but there are analogous formations elsewhere in the Neotropics (Cox et al 1989;Ellery et al 1998;McCarthy et al 1998;Brossard et al 2007) in Africa and Australia (Picker et al 2007;Midgley et al 2002;Rahlao et al 2008) and also in north America, where mound fields (prairie mounds) occur from Saskatchewan to Minnesota and south through Iowa and Missouri to Arkansas, eastern Oklahoma, and the coastal plain of Louisiana and Texas (Ross et al 1968;Mollard 1982).…”

Section: Introductionmentioning

confidence: 99%

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Deciphering earth mound origins in central Brazil

et al. 2010

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Mound fields are a common landscape throughout the world and much of the evidence for their origin has been of a circumstantial nature. It has been hypothesized that earth mounds emerge over grasslands by termite activity; alternatively, they might be formed after erosion. We tested whether a mound field in central Brazil was generated by termite activity or erosion. We used soil organic matter isotopic composition, soil chemical, physical and floristic composition to determine the origin of a mound field. If the mounds emerged by termite activity in an established grassland the soil organic matter below the mound should have the isotopic signature of C 4 dominated grassland, which contrasts with savanna C 3 + C 4 signature. Additionally, soil traits should resemble those of the grassland. All markers indicate that the mounds were formed by erosion. The soil isotopic composition, chemical traits and texture below the mound resembled those of the savanna and not those of the grassland. Moreover, most of the species present in the mound were typical of savanna. Concrete evidence is provided that mound fields in the studied area were produced by erosion of a savanna ecosystem and not termite activity. The use of the techniques applied here would improve the assessments of whether analogous landscapes are of a biogenic nature or not.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Deciphering earth mound origins in central Brazil

et al. 2010

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“…These fields are characterized by the formation of circular-shaped mounds of soil, ranging from 2 to 10 m in diameter and up to 2 m in height (Rahlao et al, 2008). The soils of these fields have low water infiltration capacity, remaining flooded between the murundus during the rainy season.…”

Section: Introductionmentioning

confidence: 99%

Arbuscular mycorrhizal fungi in soil aggregates from fields of "murundus" converted to agriculture

Carneiro

Ferreira

Souza

et al. 2015

Pesq. agropec. bras.

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-The objective of this work was to evaluate the spore density and diversity of arbuscular mycorrhizal fungi (AMF) in soil aggregates from fields of "murundus" (large mounds of soil) in areas converted and not converted to agriculture. The experiment was conducted in a completely randomized design with five replicates, in a 5x3 factorial arrangement: five areas and three aggregate classes (macro-, meso-, and microaggregates). The evaluated variables were: spore density and diversity of AMF, total glomalin, total organic carbon (TOC), total extraradical mycelium (TEM), and geometric mean diameter (GMD) of soil aggregates. A total of 21 AMF species was identified. Spore density varied from 29 to 606 spores per 50 mL of soil and was higher in microaggregates and in the area with 6 years of conversion to agriculture. Total glomalin was higher between murundus in all studied aggregate classes. The area with 6 years showed lower concentration of TOC in macroaggregates (8.6 g kg -1) and in microaggregates (10.1 g kg -1). TEM was greater at the top of the murundus in all aggregate classes. GMD increased with the conversion time to agriculture. The density and diversity of arbuscular mycorrhizal spores change with the conversion of fields of murundus into agriculture.Index terms: diversity of arbuscular mycorrhizal fungi, geometric mean diameter, total glomalin, total mycelium, total organic carbon.

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“…O terço superior dos murundus, parte seca do solo, apresenta vegetação típica do Cerrado strictu sensu, composta por espécies arbustivas e arbóreas (Resende et al, 2007;Marimon et al, 2012). Os campos de murundus também são encontrados na África, Austrália e América do Norte (Mollard, 1982;Cox et al, 1989;Rahlao et al, 2008) e, no Brasil, no bioma de Cerrado (Oliveira Filho, 1992;Silva et al, 2010). Para a conversão dessas áreas em solo agrícola, há necessidade de construção de canais de drenagem, nivelamento do terreno com a remoção dos murundus, homogeneização do solo, correção e adubação do solo, promovendo alterações nos atributos físicos, químicos e possivelmente os biológicos; no entanto, não há pesquisa sobre essas alterações e suas consequências.…”

Section: Introductionunclassified

Fungos micorrízicos arbusculares em campos de murundus após a conversão para sistemas agrícolas no cerrado

Assis

Júnior

Paulino

et al. 2014

Rev. Bras. Ciênc. Solo

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Os campos de murundus são fitofisionomias de ocorrência no bioma Cerrado com funções ecológicas importantes para a manutenção da sustentabilidade do solo; e a conversão para sistemas agrícolas pode provocar alterações nos atributos físicos, químicos e biológicos do solo ainda não avaliados, como a redução da biodiversidade de fungos micorrízicos arbusculares. O objetivo deste estudo foi avaliar como a conversão dos campos de murundus em áreas de sistema agrícola altera a comunidade de fungos micorrízicos arbusculares (FMAs). Os tratamentos constituíram-se de três áreas agrícolas submetidas ao mesmo manejo e uso agrícola em uma cronossequência (7, 11 e 14 anos) e duas na área referência [campo de murundus, em topo (TM) e entre os murundus (EM)]. Os esporos de FMAs foram extraídos, contados, e as espécies de FMAs identificadas pelas características morfológicas. O total de FMAs recuperado foi de 27 espécies, sendo nove espécies da família Acaulosporaceae, uma Ambisporaceae, sete Glomeraceae, duas Claroideoglomeraceae e oito Gigasporaceae. Desse total, as espécies Acaulospora scrobiculata, Glomus macrocarpum, e Gigaspora sp. ocorreram em todas as áreas nos dois anos estudados. As espécies Acaulospora mellea, Acaulospora cavernata, Acaulospora colombiana, Glomus diaphanum, Scutellospora reticulata e Scutellospora sp. só foram encontradas nos campos de murundus. A conversão de campos de murundus em área agrícola modificou a ocorrência e composição da comunidade de FMAs; as espécies Acaulospora scrobiculata, Glomus macrocarpum, Claroideoglomus etunicatus e Gigaspora sp ocorreram em todas as áreas e a não ocorrência de algumas espécies nas áreas de cultivo, como as espécies Acaulospora cavernata, Acaulospora colombiana, Rhizophagus diaphanus, Scutellospora reticulata e Scutellospora sp. representa perda de diversidade desses fungos. Portanto, este estudo tratou-se do primeiro relato da ocorrência e da estrutura da comunidade de FMAs em fitofisionomia de campos de murundus, contribuiu para o maior entendimento dos FMAs no bioma Cerrado e demonstrou que as alterações promovidas pela conversão da área alteraram a ocorrência e a diversidade dos fungos micorrízicos arbusculares.

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Long-term vegetation change in the Succulent Karoo, South Africa following 67 years of rest from grazing

Cited by 39 publications

References 22 publications

Deciphering earth mound origins in central Brazil

Deciphering earth mound origins in central Brazil

Arbuscular mycorrhizal fungi in soil aggregates from fields of "murundus" converted to agriculture

Fungos micorrízicos arbusculares em campos de murundus após a conversão para sistemas agrícolas no cerrado

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