scholarly journals Herbivores shape woody plant communities in the Kruger National Park: Lessons from three long-term exclosures

Koedoe ◽  
2014 ◽  
Vol 56 (1) ◽  
Author(s):  
Benjamin J. Wigley ◽  
Herve Fritz ◽  
Corli Coetsee ◽  
William J. Bond
Keyword(s):  
Soil Fertility ◽  
Soil Nutrients ◽  
Plant Communities ◽  
National Park ◽  
Woody Plant ◽  
Kruger National Park ◽  
Total Phenolic ◽  
Population Structures

The role of grazers in determining vegetation community compositions and structuring plant communities is well recognised in grassy systems. The role of browsers in affecting savanna woody plant communities is less clear. We used three long-term exclosures in the Kruger National Park to determine the effect of browsers on species compositions and population structures of woody communities. Species assemblages, plant traits relating to browsing and soil nutrients were compared inside and outside of the exclosures. Our results showed that browsers directly impact plant species distributions, densities and population structures by actively selecting for species with traits which make them desirable to browsers. Species with high leaf nitrogen, low total phenolic content and low acid detergent lignin appeared to be favoured by herbivores and therefore tend to be rare outside of the exclosures. This study also suggested that browsers have important indirect effects on savanna functioning, as the reduction of woody cover can result in less litter of lower quality, which in turn can result in lower soil fertility. However, the magnitude of browser effects appeared to depend on inherent soil fertility and climate.Conservation implications: Browsers were shown to have significant impacts on plant communities. They have noticeable effects on local species diversity and population structure, as well as soil nutrients. These impacts are shown to be related to the underlying geology and climate. The effects of browsers on woody communities were shown to be greater in low rainfall, fertile areas compared to high rainfall, infertile 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 The vegetation and floristics of the Letaba exclosures, Kruger National Park, South Africa

Koedoe ◽  
2010 ◽  
Vol 52 (1) ◽  
Author(s):  
Frances Siebert ◽  
Holger C. Eckhardt ◽  
Stefan J. Siebert
Keyword(s):  
Plant Communities ◽  
National Park ◽  
Research Programme ◽  
Vegetation Mapping ◽  
Kruger National Park ◽  
Monitoring Site ◽  
Spatial And Temporal Heterogeneity ◽  
Vegetation Surveys ◽  
Soil Moisture Availability

The construction of exclosures along two of the most important rivers in the Kruger National Park was done to investigate how patterns of spatial and temporal heterogeneity of the riparian zone is affected by fire, flood and herbivory. To assist this research programme, vegetation surveys were conducted within exclosures along the Letaba River to classify and map the vegetation of the area. The history and experimental design of the Letaba exclosures are similar to that of the Nkhuhlu exclosures along the Sabie River, which is directly related to questions surrounding elephant management. The main difference between the Nkhuhlu and Letaba exclosures is local heterogeneity, since the latter lies within the Mopaneveld, which is floristically and physiognomically much more homogenous than the vegetation of the southern Kruger National Park. Nevertheless, four plant communities, eight sub-communities and six variants were recognised and mapped for the Letaba exclosures. The vegetation description was done in relation to prevailing soil forms, differences in species richness, diversity and community structure, and therefore should serve as a basis for further detailed and broad-based botanical studies. Vegetation mapping was done to sub-community level and, where possible, to variant level. As expected in Mopaneveld vegetation, the plant communities could broadly be related to soil types, although smaller-scale variations correspond to soil moisture availability because the Mopaneveld is considered ‘event-driven’, especially in the herbaceous layer.Conservation implications: Floristic surveying and vegetation mapping of a long-term monitoring site, such as the Letaba exclosures, is seen as a baseline inventory to assist natural resource management. Linking mapping units to biodiversity strengthens the understanding needed to maintain biodiversity in all its natural facets and fluxes.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

scholarly journals The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002). Part II. Rhipicephalus appendiculatus and Rhipicephalus zambeziensis

2011 ◽  
Vol 78 (1) ◽  
Author(s):  
Arthur M. Spickett ◽  
Gordon J. Gallivan ◽  
Ivan G. Horak
Keyword(s):  
Population Dynamics ◽  
Relative Humidity ◽  
National Park ◽  
Rhipicephalus Appendiculatus ◽  
Kruger National Park ◽  
Large Herbivore ◽  
Questing Ticks ◽  
Over Time

The study aimed to assess the long-term population dynamics of questing Rhipicephalus appendiculatus and Rhipicephalus zambeziensis in two landscape zones of the Kruger National Park (KNP). Ticks were collected by dragging the vegetation monthly in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road and Skukuza) from August 1988 to March 2002. Larvae were the most commonly collected stage of both species. More R. appendiculatus were collected at Nhlowa Road than at Skukuza, with larvae being most abundant from May to August, while nymphs were most abundant from August to December. Larvae were most commonly collected in the gullies from 1991 to 1994, but in the grassland and woodland habitats from 1998 onwards. Nymphs were most commonly collected in the grassland and woodland. More R. zambeziensis were collected at Skukuza than at Nhlowa Road, with larvae being most abundant from May to September, while nymphs were most abundant from August to November. Larvae and nymphs were most commonly collected in the woodland and gullies and least commonly in the grassland (p < 0.01). The lowest numbers of R. appendiculatus were collected in the mid-1990s after the 1991/1992 drought. Rhipicephalus zambeziensis numbers declined after 1991 and even further after 1998, dropping to their lowest levels during 2002. The changes in numbers of these two species reflected changes in rainfall and the populations of several of their large herbivore hosts, as well as differences in the relative humidity between the two sites over time.

scholarly journals The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002). Part III. The less commonly collected species

2011 ◽  
Vol 78 (1) ◽  
Author(s):  
Gordon J. Gallivan ◽  
Andrea Spickett ◽  
Heloise Heyne ◽  
Arthur M. Spickett ◽  
Ivan G. Horak
Keyword(s):  
National Park ◽  
Development Stage ◽  
Kruger National Park ◽  
Ixodid Ticks ◽  
Limited Information ◽  
Host Seeking ◽  
Haemaphysalis Elliptica ◽  
Questing Ticks ◽  
Landscape Zone

Despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. This study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the Kruger National Park (KNP). From 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road, Landscape Zone 17, and Skukuza, Landscape Zone 4). Amblyomma marmoreum and Rhipicephalus evertsi evertsi were collected as larvae most commonly. Most A. marmoreum larvae were collected at Skukuza and numbers peaked from March to July. More R. evertsi evertsi larvae were collected at Nhlowa Road and numbers peaked in summer and in winter, while at Skukuza there was a single peak in spring. Haemaphysalis elliptica, Rhipicephalus simus and Rhipicephalus turanicus were collected as adults most commonly. More Ha. elliptica and R. turanicus were collected at Nhlowa Road than at Skukuza, while R. simus numbers from the two sites were approximately equal. Ha. elliptica were collected most often between February and June, and R. simus and R. turanicus during February and March. All three species were collected more frequently in gullies than in grassland or woodland. Their numbers increased in 1994/1995 following an eruption of rodents, the preferred hosts of the immature stages. The different host-seeking strategies of ticks largely determine the development stage at which they are likely to be collected during vegetation dragging and reflect a complex interaction between ticks, their hosts and the environment.

scholarly journals Long-term research in Bosque Fray Jorge National Park: Twenty years studying the role of biotic and abiotic factors in a Chilean semiarid scrubland

2010 ◽  
Vol 83 (1) ◽  
Author(s):  
JULIO R GUTIÉRREZ ◽  
PETER L MESERVE ◽  
DOUGLAS A KELT ◽  
ANDREW ENGILIS JR ◽  
M. ANDREA PREVITALI ◽  
...  
Keyword(s):  
National Park ◽  
Abiotic Factors ◽  
Biotic And Abiotic Factors

scholarly journals Plant communities and landscapes of the Parque Nacional do Limpopo, Moçambique

Koedoe ◽  
2004 ◽  
Vol 47 (2) ◽  
Author(s):  
M. Stalmans ◽  
W.P.D. Gertenbach ◽  
Filipa Carvalho-Serfontein
Keyword(s):  
Plant Communities ◽  
National Park ◽  
Building Blocks ◽  
Management Plan ◽  
Kruger National Park ◽  
Vegetation Map ◽  
Great Limpopo Transfrontier Park ◽  
Eastern Boundary

The Parque Nacional do Limpopo (PNL) was proclaimed during 2002. It covers 1 000 000 ha in Moçambique on the eastern boundary of the Kruger National Park (KNP) and forms one of the major components of the Great Limpopo Transfrontier Park. A vegetation map was required as one of the essential building blocks for the drafting of its management plan (Grossman & Holden 2002).

scholarly journals A pedogeomorphic comparison of two granitic areas in the Kruger National Park

Koedoe ◽  
1990 ◽  
Vol 33 (2) ◽  
Author(s):  
M.C. Munnik
Keyword(s):  
National Park ◽  
Climatic Factors ◽  
Parent Material ◽  
Kruger National Park ◽  
Erosion And Deposition ◽  
The Creation

Two climatically different areas on granitic materials near Phalaborwa and Pretoriuskop in the Kruger National Park were pedogeomorphologically compared and the influence of climatic factors on soil and hillslope development in the two areas was assessed. The examination of 18 hillslopes and their soils showed that while the two areas have many broad similarities, there are specific soil and hillslope differences between them with the result that each area has its own distinctive pedogeomorphic character. While comparable parent material, situation and age appear to be responsible for similarities between the areas, the differences could in most cases be accounted for by the disparity in rainfall between the two areas. It was, however, also necessary to note the role of past (and possibly current) cycles of erosion and deposition in the creation of the two types of simple hillslopes occurring in the areas.

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