scholarly journals Preliminary assessment of the impact of long-term fire treatments on in situ soil hydrology in the Kruger National Park

Koedoe ◽  
2012 ◽  
Vol 54 (1) ◽  
Author(s):  
Edward S. Riddell ◽  
Ahmed Khan ◽  
Benjamin Mauck ◽  
Simphiwe Ngcobo ◽  
Jonathan Pasi ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
National Park ◽  
Soil Strength ◽  
Fire Frequency ◽  
Kruger National Park ◽  
Ecological Processes ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic ◽  
The Impact

There has been significant attention focused on the impacts of fire frequency and season of burn on ecological processes in the Kruger National Park (KNP). Whilst there has been some examination of these fire effects on soil properties, the explicit linkages of these effects to the hydrology of soils in burnt areas has remained a gap in our understanding. During August 2010, a field scoping campaign was undertaken to assess the impacts, if any, of long-term fire treatments on the hydrology of soils on the experimental burn plots (EBPs) in the KNP. Using various hydrometric and soil physical characterisation instruments soil, hydraulic conductivity and soil strength variations were determined across the extreme fire treatment on the EBPs, the annual August (high fire frequency) plots and the control (no burn) plots, on both the granite and basalt geologies of Pretoriuskop and Satara, respectively. It was found that there were soil hydrological and structural differences to fire treatments on the basalt burn plots, but that these were not as clear on the granite burn plots. In particular, hot, frequent fires appeared to reduce the variation in soil hydraulic conductivity on the annual burn plots on the basalts and led to reduced cohesive soil strength at the surface.Conservation implications: The KNP burn plots are one of the longest running and well studied fire experiments on African savannahs. However, the impacts of fire management on hydrological processes in these water-limited ecosystems remains a gap in our understanding and needs to be considered within the context of climate and land-use changes in the savannah biome.

Soil clay content and fire frequency affect clustering in trees in South African savannas

2008 ◽  
Vol 24 (3) ◽  
pp. 269-279 ◽  
Author(s):  
Thomas A. Groen ◽  
Frank van Langevelde ◽  
Claudius A.D.M. van de Vijver ◽  
Navashni Govender ◽  
Herbert H.T. Prins
Keyword(s):  
South African ◽  
Tree Species ◽  
National Park ◽  
Clay Content ◽  
Abundant Species ◽  
Fire Frequency ◽  
Kruger National Park ◽  
Annual Rainfall ◽  
Soil Clay Content ◽  
The Impact

Abstract:In this paper, we investigate which factors determine tree clustering in Southern African savannas. This was tested by measuring clustering of trees using the T-squared sampling method in plots of the Kruger National Park experimental burning programme in South Africa. Fire return interval is the main treatment in these plots, but also several auxiliary determining parameters like clay content in the soil, diameter of tree canopies, understorey composition, tree species diversity and average annual rainfall were measured while sampling. In the Kruger National Park 48 plots distributed over four different landscape types and with three different burning treatments (never, once every 3 y and annually) were sampled. First, we related the clustering of trees to these environmental variables. When looking at the most abundant species in each plot, the analysis revealed that clustering is mainly correlated with clay content in the soil. This analysis also showed that fire frequency had a positive effect on the clustering of tree species that are not very abundant. We suggest that less abundant species might be less resistant to fire and therefore adopt a mechanism of clustering to exclude grass fires under their canopy. Finally, we tested the effect of clustering on the impact of fire on trees by analysing the relationship between the distance of a tree to its nearest neighbour and its canopy diameter. We found that clustering reduces the damaging effect of fire on trees. Our study contributes to understanding of savanna functioning by showing which processes are relevant in the distribution of savanna trees.

The impact of clay dispersion and migration on soil hydraulic conductivity and pore networks

Geoderma ◽  
2021 ◽  
Vol 404 ◽  
pp. 115297
Author(s):  
Awedat Musbah Awedat ◽  
Yingcan Zhu ◽  
John McLean Bennett ◽  
Steven R. Raine
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Hydraulic Conductivity ◽  
Clay Dispersion ◽  
Pore Networks ◽  
Soil Hydraulic ◽  
And Migration ◽  
The Impact

scholarly journals Distribution and density of Cubitermes Wasmann (Isoptera: Termitidae) mounds in the northern Kruger National Park

Koedoe ◽  
2000 ◽  
Vol 43 (1) ◽  
Author(s):  
V.W. Meyer ◽  
L.E.O. Braack ◽  
H.C. Biggs
Keyword(s):  
National Park ◽  
Water Distribution ◽  
Fire Frequency ◽  
Average Density ◽  
Kruger National Park ◽  
Termite Mounds ◽  
Land Type ◽  
Fundamental Information ◽  
The Impact ◽  
Land Types

This paper provides fundamental information on distribution and density of the genus Cubitermes, Wasm. quantified for future monitoring. After distribution trends have been established, changes in Cubitermes density over time can be brought into contention with other factors in the Kruger National Park, such as the impact of fire frequency, water distribution, and elephant density on these insects. At least ten 2 ha belt-transects were undertaken in each of the 20 northern landscape zones of the KNP. Termite mounds were recorded and their activity within was determined. Cubitermes accounts for 29.8% of all active termite mounds in the northern KNP, with an average density of 0.33 mounds/ha. Cubitermes favours the Nwambiya Sandveld (zone 32). These termites occur in high density in the Klipkoppies 1 land type (Gorge), but in low densities in the Phalaborwa 10-12, Bulweni 1-3, Letaba 1-7 and Pafuri 3-6 land types. Cubitermes mounds tend to occur in high numbers on the Nzhelele formation (Mn) (sandstones; quartzite; basalt). Mounds of this genus in the Far North are highly concentrated on the Gaudam and Moriah soil series of the Hutton form, suggesting that these termites prefer very sandy soils with medium to coarse particles.

scholarly journals Long-term effects of fire frequency and season on herbaceous vegetation in savannas of the Kruger National Park, South Africa

2012 ◽  
Vol 6 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Melinda D. Smith ◽  
Brian W. van Wilgen ◽  
Catherine E. Burns ◽  
Navashni Govender ◽  
Andre L. F. Potgieter ◽  
...  
Keyword(s):  
South Africa ◽  
National Park ◽  
Fire Frequency ◽  
Kruger National Park ◽  
Long Term Effects ◽  
Herbaceous Vegetation

scholarly journals Estimating hydraulic conductivity of a crusted loamy soil from beerkan experiments in a Mediterranean vineyard

2017 ◽  
Author(s):  
Vincenzo Alagna ◽  
Vincenzo Bagarello ◽  
Simone Di Prima ◽  
Fabio Guaitoli ◽  
Massimo Iovino ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Vegetation Cover ◽  
Soil Surface ◽  
Rainfall Event ◽  
Water Infiltration ◽  
Insertion Depth ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic ◽  
The Impact

Abstract. In bare soils of semi-arid areas, surface crusting is a rather common phenomenon due to the impact of raindrops. Water infiltration measurements under ponding conditions constitute a common way for an approximate characterization of crusted soils. In this study, the impact of crusting on soil hydraulic conductivity was assessed in a Mediterranean vineyard (western Sicily, Italy) under conventional tillage. The BEST (Beerkan Estimation of Soil Transfer parameters) algorithm was applied to the infiltration data to obtain the hydraulic conductivity of crusted and uncrusted soils. Soil hydraulic conductivity was found to vary during the year and also spatially (i.e., rows vs. inter-rows) due to crusting, tillage and vegetation cover. A 55 mm rainfall event resulted in a decrease of the saturated soil hydraulic conductivity, Ks, by a factor close to two in the inter-row areas, due to the formation of a crusted layer at the surface. The same rainfall event did not determine a Ks reduction in the row areas (i.e., Ks reduced by a non-significant factor of 1.05) because the vegetation cover intercepted the raindrops and therefore prevented alteration of the soil surface. The developed ring insertion methodology on crusted soil, implying pre-moistening through the periphery of the sampled surface, together with the very small insertion depth of the ring (0.01 m) prevented visible fractures. Consequently, beerkan tests carried out along and between the vine-rows and data analysis by the BEST algorithm allowed to assess crusting-dependent reductions in hydraulic conductivity with extemporaneous measurements alone. Testing the beerkan infiltration run in other crusted soils and establishing comparisons with other experimental methodologies appear advisable to increase confidence on the reliability of the method, that seems suitable to allow simple characterization of crusted soils.

scholarly journals Impact of fire frequency on woody community structure and soil nutrients in the Kruger National Park

Koedoe ◽  
2000 ◽  
Vol 43 (1) ◽  
Author(s):  
C.M. Shackleton ◽  
R.J. Scholes
Keyword(s):  
Community Structure ◽  
Soil Nutrients ◽  
National Park ◽  
Basal Area ◽  
Fire Frequency ◽  
Kruger National Park ◽  
Fire Season ◽  
Soil Variables ◽  
And Function

Although fire is recognised as an important determinant of the structure and function of South African savannas, there are few studies of long-term impacts. Controlled burning blocks of contrasting fire season and frequency have been maintained throughout the Kruger National Park for almost 50 years. This paper reports on a quantitative study of the Satara plots to determine the long-term impacts of fire frequency on woody community structure and soil nutrients. Increasing fire frequency significantly decreased woody plant basal area, biomass, density, height, and mean stem circumference. The number of stems per plant and the proportion of regenerative stems increased with increasing fire frequency. Effects on species richness of woody plants were inconsistent. There were no significant differences attributable to fire frequency for any of the soil variables except organic matter and magnesium. Organic carbon was highest in the fire exclusion treatment and lowest in soils from plots burnt triennially. Magnesium levels were greatest in the annually burnt soils and least in the triennial plots.

scholarly journals Using Beerkan experiments to estimate hydraulic conductivity of a crusted loamy soil in a Mediterranean vineyard

2019 ◽  
Vol 67 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Vincenzo Alagna ◽  
Vincenzo Bagarello ◽  
Simone Di Prima ◽  
Fabio Guaitoli ◽  
Massimo Iovino ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Vegetation Cover ◽  
Rainfall Event ◽  
Water Infiltration ◽  
Insertion Depth ◽  
Infiltration Process ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic ◽  
The Impact

AbstractIn bare soils of semi-arid areas, surface crusting is a rather common phenomenon due to the impact of raindrops. Water infiltration measurements under ponding conditions are becoming largely applied techniques for an approximate characterization of crusted soils. In this study, the impact of crusting on soil hydraulic conductivity was assessed in a Mediterranean vineyard (western Sicily, Italy) under conventional tillage. The BEST (Beerkan Estimation of Soil Transfer parameters) algorithm was applied to the infiltration data to obtain the hydraulic conductivity of crusted and uncrusted soils. Soil hydraulic conductivity was found to vary during the year and also spatially (i.e., rows vs. inter-rows) due to crusting, tillage and vegetation cover. A 55 mm rainfall event resulted in a decrease of the saturated soil hydraulic conductivity,Ks, by a factor of 1.6 in the inter-row areas, due to the formation of a crusted layer at the surface. The same rainfall event did not determine aKsreduction in the row areas (i.e.,Ksdecreased by a non-significant factor of 1.05) because the vegetation cover intercepted the raindrops and therefore prevented alteration of the soil surface. The developed ring insertion methodology on crusted soil, implying pre-moistening through the periphery of the sampled surface, together with the very small insertion depth of the ring (0.01 m), prevented visible fractures. Consequently, Beerkan tests carried out along and between the vine-rows and data analysis by the BEST algorithm allowed to assess crusting-dependent reductions in hydraulic conductivity with extemporaneous measurements alone. The reliability of the tested technique was also confirmed by the results of the numerical simulation of the infiltration process in a crusted soil. Testing the Beerkan infiltration run in other crusted soils and establishing comparisons with other experimental methodologies appear advisable to increase confidence on the reliability of the method that seems suitable for simple characterization of crusted soils.

scholarly journals Long term effects of fire frequency and season on the woody vegetation dynamics of the Sclerocarya birrea/Acacia nigrescens savanna of the Kruger National Park

Koedoe ◽  
2000 ◽  
Vol 43 (1) ◽  
Author(s):  
B.W. Enslin ◽  
A.L.F. Potgieter ◽  
H.C. Biggs ◽  
R. Biggs
Keyword(s):  
National Park ◽  
Structural Changes ◽  
Environmental Parameters ◽  
Woody Species ◽  
Fire Frequency ◽  
Kruger National Park ◽  
Woody Vegetation ◽  
Long Term Effects ◽  
Season Of Burn

A lack of knowledge together with vacillating fire management approaches in the Kruger National Park until the mid 1950s, gave rise to a long term fire research experiment aimed at shedding light on savanna responses to various combinations of fire fre- quencies and seasons. This trial was laid out in 1954 in four of the six major vegetation zones of the park. With the future of the experiment now being reconsidered, full scale vegetation surveys have been conducted on all the plots and compared to the surveys done in 1954. This paper examines the woody vegetation responses to fourteen fire treatments in the Knobthorn/Marula savanna. Parameters of interest were woody species composition responses, together with tree & shrub density and structural changes. The results indicate that no significant changes in woody species had occurred for the peri- od 1954 vs 1998, while density decreased on biennial and increased on triennial treatments. The proportion of single stemmed plants increased over the period. Season of burn has a marked effect on structure, with April and August burns giving rise to the largest basal areas but the lowest heights. Environmental parameters such as climate, varying herbivory and differing soils, and their respective interactions on vegetation morphology, together with fire behaviour, further influenced results.

scholarly journals Las agregaciones de desove de Tylosurus pacificus (Beloniformes: Belonidae) y su pesca en el Parque Nacional Natural Utría (Pacífico colombiano)

2016 ◽  
Vol 65 (1) ◽  
pp. 77 ◽  
Author(s):  
Tatiana Correa Herrera ◽  
Juan Diego Correa Rendón ◽  
Viviana Márquez Velásquez ◽  
Luz Fernanda Jiménez Segura ◽  
Juan David Carvajal Quintero
Keyword(s):  
National Park ◽  
Gonadal Development ◽  
Ecological Processes ◽  
Spawning Aggregations ◽  
Reproduction Study ◽  
New Moon ◽  
Complex Relationships ◽  
The Impact ◽  
Average Fertility

Some species of marine fish have complex relationships with coastal ecosystems during their reproductive periods, as the needle fish Tylosurus pacificus that forms spawning aggregations in gravel beaches in Utría Park. We described fishery and some aspects of the reproductive biology of T. pacificus and proposed some strategies to mitigate the impact of this event and associated ecological processes. Fisheries monitoring were conducted between April 2008 and February 2009 in the Utría National Park, Colombian Pacific. Catch volumes, length structure, sex ratio and fecundity (n= 84) were analyzed. The total length ranged among 60.5 and 104 cm with a mean and standard deviation of 85.35 ± 9.09 cm. The average fertility of oocytes per gonad was 189 685.56, with a mode of 8 mm diameter and an asynchronous gonadal development. This species spawns collectively on the beach when the tide reaches the highest level during full and new moon, usually in the evening. Fishermen of a near town take advantage of the spawning aggregation of this species. The reproduction study of T. pacificus and ecological processes associated with their spawning, should be expanded to give adequate use, and ensure the sustainability of their fishery over the long term.

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