Vertical distribution of grass and tree roots in arid ecosystems of Southern Africa: niche differentiation or competition?

Hipondoka, Martin; Aranibar, Julieta N.; Chirara, C.; Lihavha, M; Macko, Stephen A.

doi:10.1006/jare.2002.1093

Cited by 86 publications

(88 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Some researchers (Mordelet et al, 1997;Scholes, 1997; documented that trees or shrubs have different rooting patterns than grasses or herbs in mixed tree/ shrub-grass systems. Such results correspond with other competition experiments on water partitioning between grasses and shrubs in the 2-layer hypothesis (Walter, 1971;Hipodonka et al, 2003;Ludwig et al, 2004b), which states that grasses acquire water and soil nutrients only from the upper soil layer, while woody vegetation has exclusive access to the deeper soil layer (Roux et al, 1995). This hypothesis has not been consistently supported (Roux et al, 1995;Mordelet et al, 1997;Reynolds et al, 2000Reynolds et al, , 2004.…”

Section: Fine Root Distribution and Belowground Interactionssupporting

confidence: 81%

“…Walter (1939) proposed a 2-layer hypothesis to explain the coexistence of savanna trees and grasses. This hypothesis is based on vertical niche partitioning and assumes that grasses are more efficient in using water from surface soil than trees (Hipodonka et al, 2003;Ward et al, 2013). Ward et al (2013) found that the 2-layer model worked in some moist savannas and tallgrass prairies and that it was an appropriate model to explain soil-water spatial partitioning and tree-grass codominance in dry savannas.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fine root distribution and belowground interactions in an alley silvopasture system in northern China

Lai¹,

Zhang²,

Wu³

et al. 2014

Turk J Agric For

View full text Add to dashboard Cite

Successful agroforestry management depends on the interactions between the mixed species. Belowground interactions between shrubs and native grasses are complicated and poorly understood in China's agroforestry practice, especially in the silvopasture systems of droughty northern China. The distribution of fine roots (<2 mm) in an alley silvopasture system consisting of Caragana microphylla Lam. and local grasses was compared to those in a degraded pasture plot using soil cores. Fine root production was examined in these plots using ingrowth cores. We found that the introduction of C. microphylla did not change the vertical distribution pattern of fine roots of grassy plants but had a great impact on belowground production in the ecosystem. Grass fine roots decreased with depth in both the silvopasture system and the degraded pasture. Grass fine roots were mostly distributed in the top 40 cm of the soil, but they extended to deeper soil layers through root elongation. C. microphylla, in contrast, occupied the deeper soil layer, in which water was continuously available. We conclude that the belowground interactions between native grasses and C. microphylla in sandy soil can be explained by Walter's 2-layer hypothesis, which is used to explain the coexistence of trees and grasses. Our results draw attention to the interspecific configuration of the silvopasture system and belowground interactions of plants in semiarid and arid regions.

show abstract

Section: Fine Root Distribution and Belowground Interactionssupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Fine root distribution and belowground interactions in an alley silvopasture system in northern China

Lai¹,

Zhang²,

Wu³

et al. 2014

Turk J Agric For

View full text Add to dashboard Cite

show abstract

“…Models based on the 'Walter hypothesis' -4-have been widely applied in literature (Walker et al, 1981, Walker and Noy-Meir, 1982, Eagleson and Segarra, 1985, van Langevelde et al, 2003. Some experiments and observations have supported 'Walter hypothesis' (Knoop and Walker, 1985, Sala et al, 1989, Pelaez et al, 1994 but many others have cast doubts on the existence of vertical rooting niche separation (Scholes and Walker, 1993, Belsky, 1990, Le Roux et al, 1995, Mordelet et al, 1997, Smit and Rethman, 2000, Hipondoka et al, 2003.…”

Section: What Is Special About the Savanna Environment That Allows Trmentioning

confidence: 99%

Tree–grass co-existence in savanna: Interactions of rain and fire

Accatino

Michele

Vezzoli

et al. 2010

Journal of Theoretical Biology

114

105

View full text Add to dashboard Cite

The mechanisms permitting the co-existence of tree and grass in savannas have been a source of contention for many years. The two main classes of explanations involve either competition for resources, or differential sensitivity to disturbances. Published models focus principally on one or the other of these mechanisms. Here we introduce a simple ecohydrologic model of savanna vegetation involving both competition for water, and differential sensitivity of trees and grasses to fire disturbances. We show how the coexistence of trees and grasses in savannas can be simultaneously controlled by rainfall and fire, and how the relative importance of the two factors distinguishes between dry and moist savannas. The stability map allows to predict the changes in vegetation structure along gradients of rainfall and fire disturbances realistically, and to clarify the distinction between climate-and disturbance-dependent ecosystems.

show abstract

“…In the HSL, surface water is negligible and the vegetation primarily depends on groundwater for survival and development [31][32][33][34]. Duan et al [21] found that the spatio-temporal variation of vegetation in the HSL is dominated by groundwater availability and only slightly influenced by soil physicochemical properties such as soil texture, soil organic content, soil salinity, and plant physiology.…”

Section: Introductionmentioning

confidence: 99%

Spatio-Temporal Patterns of Water Table and Vegetation Status of a Deserted Area

Duan

Liu

Wang

et al. 2015

Water

View full text Add to dashboard Cite

Understanding groundwater-vegetation interactions is crucial for sustaining fragile environments of desert areas such as the Horqin Sandy Land (HSL) in northern China. This study examined spatio-temporal variations in the water table and the associated vegetation status of a 9.71 km 2 area that contains meadowland, sandy dunes, and intermediate transitional zones. The depth of the water table and hydrometeorologic parameters were monitored and Landsat Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) data were utilized to assess the vegetation cover. Spatio-temporal variations over the six-year study period were examined and descriptive groundwater-vegetation associations developed by overlaying a water table depth map onto a vegetation index map derived from MODIS. The results indicate that the water table depends on the local topography, localized geological settings, and human activities such as reclamation, with fluctuations occurring at annual and monthly scales as a function of precipitation and potential evapotranspiration. Locations where the water table is closer to the surface tend to have more dense and productive vegetation. The water table depth is more closely associated with vegetative density in meadowlands than in transitional zones, and only poorly associated with vegetation in sandy dunes.

show abstract

Vertical distribution of grass and tree roots in arid ecosystems of Southern Africa: niche differentiation or competition?

Cited by 86 publications

References 10 publications

Fine root distribution and belowground interactions in an alley silvopasture system in northern China

Fine root distribution and belowground interactions in an alley silvopasture system in northern China

Tree–grass co-existence in savanna: Interactions of rain and fire

Spatio-Temporal Patterns of Water Table and Vegetation Status of a Deserted Area

Contact Info

Product

Resources

About