Top PDF Structure and composition of woody vegetation in two important bird areas in southern Zimbabwe

Structure and composition of woody vegetation in two important bird areas in southern Zimbabwe

Structure and composition of woody vegetation in two important bird areas in southern Zimbabwe

This study assessed the status of woody vegetation structure and composition in two Important Bird Areas (IBA) i.e. Manjinji Pan and Save-Runde Junction located in southeastern Zimbabwe. The objectives of this study were to: (i) determine the woody vegetation structure and composition of the study areas and (ii) find out any differences and similarities in woody vegetation between the two IBAs. Data about woody vegetation were collected from 40 randomly placed sample plots from both study areas. Tree density was higher in Manjinji Pan IBA (406.67 ± 16.86 trees ha -1 ) than Save-Runde Junction IBA (275.83 ± 17.62 trees ha -1 ). In contrast, Save-Runde Junction IBA had higher numbers of stems per plant (2.88 ± 0.22), species richness (59) and diversity (H′ = 3.28) than Manjinji Pan IBA: numbers of stems per plant (2.16 ± 0.12), species richness (43) and diversity (H′ = 2.90). No significant differences were recorded in woody plant height, shrub and dead plant densities. The findings suggest that several factors including fires, herbivory and human activities could be influencing the woody vegetation in the two IBAs. However, further research is suggested to better understand the drivers of woody vegetation variation in IBAs occurring in savanna ecosystems. It is recommended that species richness and diversity of woody plants should be maintained and invasive plant species controlled for the conservation of endemic and migratory avifauna.
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Variation in woody vegetation structure and composition in a semi-arid savanna of southern Zimbabwe

Variation in woody vegetation structure and composition in a semi-arid savanna of southern Zimbabwe

The results of the present study show that there were significant differences in basal area, browsed plant density, shrub density and species diversity across the three strata in Gonarezhou National Park. The structural and compositional differences across the three strata in Gonarezhou National Park were possibly related to herbivory, fires, human activities, droughts, geology and soil differences (Tafangenyasha, 1997a, 1998; Gandiwa and Kativu, 2009; Gandiwa et al., 2011a, b). Repeated fires and elephant browsing are known to stress normal growth and affect the health of the woodland and may top-kill woody vegetation (Bond, 2008; Ryan and Williams, 2011; Asner and Levick, 2012). Furthermore, elephant populations in Gonarezhou National Park have over the years continued to increase, from ~3100 in 1969 to ~9100 in 2009 (Dunham et al., 2010). This increase may also have been influenced by the recent non-culling of elephants in the park since the last elephant cull in Gonarezhou National Park was conducted in 1993. Tsetse fly (Glossina spp.) (Diptera: Glossinidae) eradication teams cleared riparian woodlands from parts of the major river systems, i.e. Save, Runde and Mwenezi, in Gonarezhou National Park, also negatively influencing the woody vegetation (Gandiwa and Kativu, 2009).
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Habitat-specific vegetation and seasonal drivers of bird community structure and function in southern Patagonian forests

Habitat-specific vegetation and seasonal drivers of bird community structure and function in southern Patagonian forests

Conserving habitat heterogeneity at local and regional scales is a key process in maintaining bird diversity patterns in many forest ecosystems around the world (Wiens 1989). At the same time, certain habitats may have greater conservation value than others, if specific areas maintain higher levels of biodiversity and contain the same species as adjacent habi- tats. In this context, it is important to know how the patterns of avian species richness and composition respond both with- in and between vegetation types (Lindenmayer et al. 2010). Díaz (2006), for example, showed that mixed oak-pine transi- tion zones in Spain increased bird species richness. However, these areas did not significantly increase bird abundance, com- pared to either pure oak woodlands or pure pine woodlands. Also, the same study determined the strong influence of un- derstory vegetation (species composition, cover and height) in increasing both bird species richness and abundance. In our study, forested and associated non-forested habitats of- fered varying ecological conditions and advantages for differ- ent bird species. Some bird species showed clear preferences for specific habitat types, while others were more generalists. For example, the Magellanic Woodpecker was strongly asso- ciated with MD forests, probably due to the fact that dead and decaying trees associated with its food (Cerambicidae larvae) and nest building sites are more common in these forests than in MDE. Another example is the Green-backed Firecrown, which was found only in MDE habitats that had Embothrium coccineum, whose red tubular flower provides abundant nec- tar. Such species-specific habitat associations have previously been described in these forests for understory plant and insect communities (e.g., Lencinas et al. 2005, 2008a,b), and further illustrate the need to consider the entire landscape in manage- ment and conservation initiatives (Gustafsson et al. 2012).
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Structure and composition of Spirostachys africana woodland stands in Gonarezhou National Park, southeast Zimbabwe

Structure and composition of Spirostachys africana woodland stands in Gonarezhou National Park, southeast Zimbabwe

ABSTRACT We investigated the structure and composition of Spirostachys africana woodlands in Gonarezhou National Park (GNP), southeast Zimbabwe. We divided the GNP into three strata, namely northern, central and southern GNP, based on physical feature such as major perennial rivers. The main objective was to determine whether the structure and composition of S. africana woodlands varied across the GNP. In addition, we evaluated whether herbivory and fires played important roles in influencing the structure and composition of S. africana woodland stands. A stratified random sampling design was used and data were collected from a total of 60 sample plots. The following variables were recorded in each study plot: woody plant height, species name, plant status (alive or dead), fire or browse evidence and number of stems per plant. A total of 2,588 woody plants comprising of 73 woody species were recorded from the sampled S. africana woodlands in the GNP. Our results showed that woody species diversity, woody plant heights, shrub density, density of dead plants, sapling density, density of fire damaged plants, and number of stems per plant were significantly different across the S. africana woodlands in GNP. In contrast, only densities of trees and browsed plants did not differ significantly across the GNP. Most plots in the southern GNP had higher tree and sapling densities and taller trees whereas those in the northern GNP had higher densities of fire damaged plants. In addition, plots from central GNP were characterised with higher shrub densities of S. africana woodlands. Overall, our results suggest that there are both structural and compositional differences of S. africana woodland stands across the GNP. Evidence of herbivory did not differ significantly across the GNP suggesting that plants were uniformly affected by herbivores. However, fire evidence seemed to vary across the GNP, with areas having frequent fires being more degraded and having to some extent more woody vegetation species diversity.
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Status of woody vegetation along riparian areas in Gonarezhou National Park, Zimbabwe

Status of woody vegetation along riparian areas in Gonarezhou National Park, Zimbabwe

There are several factors not investigated in the present study which could have influenced the riparian vegetation structure and composition of Gonarezhou major rivers. It is apparent that degraded sites of Save and Runde riparian areas have been also influenced by areas formerly disturbed by humans in Gonarezhou (O'Connor and Campbell, 1986; Gandiwa and Kativu, 2009; Mombeshora and Le Bel, 2009). The then resident people vacated these areas in 1968, because of the legislative removal of inhabitants from areas proclaimed as game sanctuaries (ZPWMA, 2011). Changes in plant structure in Gonarezhou riverine woodlands and mixed shrub woodlands during the dry season have been also attributed to termite activity (O'Connor and Campbell, 1986). Moreover, droughts have been noted as important in reducing the protective tree cover along river banks in Gonarezhou as a result of tree mortality (e.g., Tafangenyasha, 1997). However, in this present study, we recorded a relatively low density of dead plants in the riparian areas. Gonarezhou is located in the downstream of the south-easterly flowing rivers that drain Zimbabwe, and as a result, it is at risk of receiving adverse hydrological changes from upstream developments. The effects directly impact on the fauna and flora, for example, if large quantities of silt are transported downstream the river water pools inevitably disappear, and if water is not released from upstream impoundments the recharge in the rivers diminish with consequent loss in aquatic life and related degradation on floodplain vegetation.
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Comparison of Nutritional Composition of Bird Egg Varieties Found in Southern Nigeria:  A Preliminary Study

Comparison of Nutritional Composition of Bird Egg Varieties Found in Southern Nigeria: A Preliminary Study

The results of the proximate composition and energy value of the five raw and boiled eggs presented in Table 1 indicate that, protein content varied signifi- cantly (p < 0.05) among all the raw samples with guinea fowl egg having the highest protein content (20.3% ± 0.15%) and turkey egg having the lowest (11.5% ± 0.44%). Raw guinea fowl egg also had the highest fat content (13.8% ± 0.17%) and this was significantly (p < 0.05) higher than the others. Total carbo- hydrate and sugar content were low in all the raw eggs and some of the values were statistically different (p < 0.05). Calculated energy values were much lower than those gotten by bomb calorimetry; in the raw eggs, calculated values ranged from 628 KJ to 871 KJ and varied greatly among the egg species with guinea fowl egg recording the highest value. Among the boiled eggs, a similar trend was ob- served with guinea fowl egg having the highest protein and fat contents (26.6% ± 0.06% and 18.0% ± 0.15%, respectively) and this was significantly (p < 0.05) higher than the others. Boiled turkey egg had the highest ash content (5.4% ± 0.03%) and this was significantly greater than the others which ranged between 1.7% to 4.0%. Comparing both raw and boiled samples, it was generally observed that the raw eggs had higher moisture content and the boiled eggs had higher dry matter composition.
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Vegetation Structure and Carbon Stocks of Two Protected Areas Within the South-Sudanian Savannas of Burkina Faso, West Africa

Vegetation Structure and Carbon Stocks of Two Protected Areas Within the South-Sudanian Savannas of Burkina Faso, West Africa

Nazinga Game Ranch was created in 1979 (Fig. 1) and is spread over an area of 97,536 ha at an altitude of 280m asl [14]. According to Burkina Faso’s legislation, it has been classified as a protected area, listed as “Wildlife Reserve” and it is very well known as a tourist destination [15]. There is a single dry season running from October to May and a single rainy season, from June to September. It has a mean annual rainfall of 900 mm [14]. The average annual temperature is 27.1 °C. The Nazinga Game Ranch is traversed by Sessile River and its two tributaries i.e. Dawevele and Nazinga Rivers; the rivers have characteristic seasonal flows. The vegetation has the characteristics of Southern Sudanian savanna. Typical species of the area include; Shea Tree (Vitellaria paradoxa C.F. Gaertn.), Kodayoru Tree (Terminalia laxiflora Engl. & Diels), Female Gardenia (Gardenia erubescens Stapf & Hutch.), Lingahi Tree (Afzelia africana Sm.), African Birch (Anogeissus leiocarpa (DC.) Guill. & Perr.) among others [16]. For better management purposes, the Nazinga Game Ranch has been divided into four zones: (i) conservation zone, (ii) buffer zone, (iii) commercial hunting zone, and (iv) village hunting zone. The conservation zone consists of 9% and the buffer zone consists of 5% of the total area. The commercial hunting zone and the village hunting zone make 86% combined of the total area [17]. A few settlements are also located in the commercial hunting zone and village hunting zone. The area has been once known to be one of the least populated areas in Burkina Faso, but has been subjected to increasing migrations after the Sahelian drought in the 1970s [14] . The agriculture is the mainstay for the local people and the major agricultural crops are Corn (Zea mays L.), Sorghum (Sorghum bicolor (L.) Moench), Pearl millet (Pennisetum glaucum (L.) R. Br.) and Peanut (Arachis hypogaea L.).
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Understory vegetation in planted pine forests governs bird community composition and diversity in the eastern Mediterranean region

Understory vegetation in planted pine forests governs bird community composition and diversity in the eastern Mediterranean region

The most common bird species observed in this study (across the three types of habitat) were the Sardinian warbler (Sylvia melanocephala) with 459 individuals, the Common chaffinch (Fringilla coelebs) with 173 individ- uals and the Blackbird (Turdus merula) with 130 indi- viduals. The bird community networks differed across the three forest types (Fig. 4). Three resident species (S. melanocephala, Garrulus glandarius and Streptopelia decaocto) consistently presented across the three forest types (see also Table 5 in Appendix). Compared to their relatively high abundance in the DF and OF habitats, the European robin (Erithacus rubecula) was not spotted in the dense pine forest with no understory (NF). Two spe- cies (Great tit, Parus major, and Blackbird, Turdus mer- ula) were also very rare in the (NF) habitat (Table 1). On the other hand, the abundance of Common chaf- finch (Phylloscopus collybita) was higher in the NF habi- tat, but not significantly (Table 1).
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Woody Species Diversity and Composition of Dry Woodland Vegetation in West Shewa, Central Ethiopia: Implications for Their Sustainable Management

Woody Species Diversity and Composition of Dry Woodland Vegetation in West Shewa, Central Ethiopia: Implications for Their Sustainable Management

socioeconomic significance of the dry land forest in Ethiopia, few policies and practices try to address issues related to these versatile resources when planning development of dry lands [4, 5, 7]. As a result, these dry forests are under increasing anthropogenic and natural pressures [8-11], also argued that there is a massive transformation of forestland into farmlands in the Combretum-Terminalia woodland belt, ignoring the various socio-economic and ecological benefits that can be obtained through sustainable management and conservation of the forest vegetation. Moreover, different studies made in Ethiopia have indicated that these vegetations are declining from time to time [2, 6, 12, 13]. The major factors which affected the natural vegetation of the country were agricultural expansion, settlement, deforestation, land degradation, and invasive species [14, 15]. The growing pressure on dry forest resources is partly due to inadequate information on the regeneration status of high value tree species, especially those produce commercial gum and resins at national scale is among problems hindering strategic consideration of dry forests [1]. On the top this; the diversity and composition of woody species is not well studied due to the absence of a systematic and rigorous data collection system at national level in several developing countries. Nowadays, the professional efforts to evaluate the population status of woody species are systematically attempted since globally gum and resin production considered as an essential medium of economy and sustainable development. Therefore, the objective of this
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The Diversity and Composition of Woody Plants in Chebera Churcura National Park (CCNP), Southern Ethiopia

The Diversity and Composition of Woody Plants in Chebera Churcura National Park (CCNP), Southern Ethiopia

CCNP is found with in western side of the central Omo Gibe basin in between Dawro zone and Konta special wereda -of SNNPRS in Ethiopia. The park is lo- cated in the south western natural forest belt of the country. The forest in the south west part of the country is characterized by secondary forest types of moist evergreen montane forests within altitudinal range of 1100 - 2700 m.a.s.l. The annual rainfall varies between 1200 mm and over 2000 mm (Mengistu, 2002). Bench Maji, Sheka zones, Konta special woreda , and partly Dawuro zone are areas where patches of forests are found. The study area is reached after a drive of 420 km & 460 kms to the south west of Hawassa and Addis Ababa, respec- tively. It is also reached after a drive of 120 km from Jima town to the east. It covers an area of 1190 km 2 . Its geographical range lies between an altitude from
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Vegetation, floristic composition and structure of a tropical montane forest in Cameroon

Vegetation, floristic composition and structure of a tropical montane forest in Cameroon

The climate of the RHFR is typical of equatorial Cameroon, being hot and humid, with two distinct seasons: dry (December to March) and wet (April to November). An annual total rainfall of 5000 mm has been reported for the reserve (Nembot & Tchanou 1998). Temperature fluctuates with elevation, with the coldest temperatures at the top of Mount Rata; although no climate station is located in this area, Nembot and Tchanou (1998) reported a mean temperature of 22°C for the reserve. This reserve forms a topographic platform for different river sources that supply the Chad, Benue, Sanaga, Congo and Manyu rivers (Ngwa 1978). Rivers originating in this reserve flow in five directions: north into Lake Chad via the Logone River; northwest via the Benue River, the Kimbi River and the Katsina Ala River; southwest into the Gulf of Guinea via the Ndian (Moriba), Moko, Meme, Mungo and Wouri rivers; southeast via the Kadei River, a tributary of the Congo River, and west into Nigeria via the Munaya and Mbo rivers.
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Habitat quality is more important than matrix quality for bird communities in protected areas

Habitat quality is more important than matrix quality for bird communities in protected areas

habitat quality because we focus on forest birds. We analyzed ma- trix quality within 5 km radius around the reserves. 5 km radius was selected to make sure that the matrix could have impact on species with large home ranges such as large raptors. Larger radii could have resulted in an excessive overlap in matrices of neigh- boring areas. A portion of the matrices around reserves adjacent to or near the Russian border fell outside the Finnish land- cover data, and comparable data from Russia were not available. In such cases, landscape structure in the buffer zone was estimated assum- ing that undisturbed areas along the Russian border have identical landscape composition compared with the reserve itself. This as- sumption is reasonable because Finnish forest reserves represent natural, undisturbed areas corresponding to the state of forests along the Russian side of the border. As indicator for low qual- ity, we used the proportion of shrubs and saplings (habitat class 8; Table 1), because intense clear- cutting activities result in land- scapes dominated by young trees.
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Woody Species Composition in Relation to Spatial and Environmental Gradients in Acacia-Commiphora Vegetation Ecosystem of Ethiopia

Woody Species Composition in Relation to Spatial and Environmental Gradients in Acacia-Commiphora Vegetation Ecosystem of Ethiopia

Abstract: Woody species composition at local scale has been studied well in the tropics. However, how the species composition is related to the spatial and environmental gradients was poorly studied. Here, we examined the effects of the topographic aspects and altitude gradient on the species composition across four sites of Acacia-Commiphora woodland and bushland ecosystem. We collected data on the number of species, number of individuals, dbh and total height for those dbh was ≥ 2.5cm from ten quadrates (size: 50 × 50 m each) along transect of about 2kms laid out in each four sites. Altitude was taken with handheld GPS (Garmin GPSMAP 60CSx) and topographic aspects were recorded for each quadrate. The species composition was dissimilar among the four sites, across altitudinal gradients and topographic aspects. Here, the majority of the rare species are specific to each site, for example, Olea europea is the rare species in site (A) but not recorded in the rest of the three sites. Our overall results underscore the importance of considering the spatial scales and environmental variables in designing conservation methods. Nevertheless, identifying the biotic attributes driving the species composition in the ecosystem envisages further studies.
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Evaluation of Woody Vegetation and Loblolly Pine Responses to Aminocyclopyrachlor.

Evaluation of Woody Vegetation and Loblolly Pine Responses to Aminocyclopyrachlor.

Ailanthus [Ailanthus altissima (Mill.) Swingle], black locust (Robinia pseudoacacia L.), and sweetgum (Liquidambar styraciflua L.) are common species in the Eastern U.S. and are weedy in many non-cropland sites throughout the southeastern United States (Little 2006). Although sweetgum and black locust are native to this region (Figure 1), ailanthus is shown to be quite invasive outside of its native habitat of China (Ingo 1995). Similarly, all three species can regenerate prolifically through either root or stump sprouting from adventitious buds at or below ground level. Furthermore, these species are known to share root systems causing a complexity of problems in terms of herbicidal treatments whereas chemicals may travel and harm nearby vegetation even when treated plant(s) died (Haymond and McNabb 1994; Leonard and Murphy 1965; Schalau 2006). These traits decrease the value of timber, prohibit efficient growth of high value timber species, and can become hazardous if not controlled (Hamilton 1995; Siso and Burzycki 2004).
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Vegetation, floristic composition and structure of a tropical montane forest in Cameroon

Vegetation, floristic composition and structure of a tropical montane forest in Cameroon

Annonaceae Xylopia africana (Benth.) Oliv.. Annonaceae Xylopia hypolampra Mildbr.[r]

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Factors governing selective impacts of elephant on woody vegetation

Factors governing selective impacts of elephant on woody vegetation

Seasonal effects The effect of season was that specific impacts tended to occur during certain times of the year. In general, less severe impacts (snapping of stems and leaf stripping) occurred during the wet and cool-dry seasons, while both less severe and severe impacts (digging, uprooting and snapping of trunks) occurred during the hot-dry season. Previous studies also indicated that elephants inflicted severe impacts during the hot-dry to early wet seasons. However, these studies placed emphasis on impacts on canopy trees in localised areas (Lamprey et al., 1967; Child, 1968; Thompson, 1975; Field and Ross, 1976; Mwalyosi, 1987; Conybeare, 1991; Cumming et al., 1997). The results of this study indicated the seasonal effects with respect to impacts on in individual woody species and size classes as fully discussed in the following sections. Limited tree felling or bark removal was recorded during this study suggesting that such impacts may occur in time and space under specific conditions as will be discussed in Chapter 5.
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Modelling vegetation structure-based bird habitat resources in Australian temperate woodlands, using multi-sensors

Modelling vegetation structure-based bird habitat resources in Australian temperate woodlands, using multi-sensors

While existing guild schemes are usually focused on traits that mainly related to bird feeding behaviours and/or sources, they generally do not incorporate vegetation structural information. For example, information on the average height at which birds builds nest above the ground [Marchant, 1990] is not typically useful for establishing conventional types of functional groups; rather it is treated as ancillary information. When field studies have revealed relationships between functional groups of bird species and vegetation structure this information has not been used to classify the bird species into functional groups but to address questions concerning guilds; e.g. Rodewald and Smith [1998] compared two timber cutting treatments in American oak-hickory forest on understory and canopy nesting birds. We concluded that none of the existing grouping schemes was explicitly established based upon vegetation structural attributes that relate to species-specific habitat resource use. Therefore, a new functional group classification was needed for this study.
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Use of remote sensing in landscape-scale vegetation degradation assessment in the semi- arid areas of the Save catchment, Zimbabwe.

Use of remote sensing in landscape-scale vegetation degradation assessment in the semi- arid areas of the Save catchment, Zimbabwe.

ii Abstract The deteriorating condition of land in parts of the world is negatively affecting livelihoods, especially, in rural communities of the developing world. Zimbabwe has experienced significant vegetation cover losses, particularly, in low and varied rainfall areas of the Save catchment. The concern that Save catchment is undergoing huge vegetation losses has been largely expressed, with the causes being environmental and anthropogenic. Given the magnitude of the problem, research studies have been undertaken to assess the extent of the problem in the south eastern region of Zimbabwe, which, nevertheless, have been mainly localized. The present study seeks to identify and quantify vegetation degradation at a landscape scale in the Save catchment of Zimbabwe, using remote sensing technologies. To achieve this, two objectives were set. The first objective provided a review of the application of satellite earth observations in assessing vegetation degradation, the causes, as well as associated impacts at different geographical scales. A review of literature has revealed the effectiveness of satellite information in identifying changes in vegetation condition. A second objective sought to establish the extent of vegetation degradation in the Save catchment. Moderate Resolution Imaging Spectroradiometer- Normalised Difference Vegetation Index (MODIS NDVI) datasets were used for mapping NDVI trends over the period 2000-2015. Further analysis involved application of residual trend (RESTREND) method to separate human influences from climatic signal on vegetation degradation. RESTREND results showed an increasing trend in NDVI values in about 33.6% of the Save catchment and a decreasing trend in about 18.3% from 2000 to 2015. The results of the study revealed that about 3,609,955 hectares experienced significant human induced vegetation degradation. Approximately 38.8% of the Save Catchment was significantly degraded (p< 0.05), 3.6%, 12.8%, and 22.4% of which were classified as severely, moderately, and lightly degraded, respectively. Severe degradation was mainly found in the central districts of the Save Catchment, mainly Bikita, Chipinge and northern Chiredzi. The results of this study support earlier reports about ongoing degradation in the catchment. Vegetation changes observed across the landscape revealed different degrees of the impacts of land use activities in altering the terrestrial ecosystems. The study demonstrated the usefulness of the RESTREND method in identifying vegetation loss due to human actions in very low rainfall areas.
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Small Patches of Riparian Woody Vegetation Enhance Biodiversity of Invertebrates

Small Patches of Riparian Woody Vegetation Enhance Biodiversity of Invertebrates

Received: 8 October 2020; Accepted: 26 October 2020; Published: 2 November 2020   Abstract: Patches of riparian woody vegetation potentially help mitigate environmental impacts of agriculture and safeguard biodiversity. We investigated the effects of riparian forest on invertebrate diversity in coupled stream-riparian networks using a case study in the Zwalm river basin (Flanders, Belgium). Agriculture is one of the main pressures in the basin and riparian forest is limited to a number of isolated patches. Our 32 study sites comprised nine unshaded “unbuffered” sites which were paired with nine shaded “buffered” sites on the same stream reach, along with five ‘least-disturbed’ sites and nine downstream sites. We sampled water chemistry, habitat characteristics and stream and riparian invertebrates (carabid beetles and spiders) at each site. Three methods were used to quantify riparian attributes at different spatial scales: a visually-assessed qualitative index, quantitative estimates of habitat categories in six rectangular plots (10 × 5 m) and geographic information system (GIS)-derived land cover data. We investigated relationships between invertebrates and riparian attributes at different scales with linear regression and redundancy analyses. Spiders and carabids were most associated with local riparian attributes. In contrast, aquatic macroinvertebrates were strongly influenced by the extent of riparian vegetation in a riparian band upstream (100–300 m). These findings demonstrate the value of quantifying GIS-based metrics of riparian cover over larger spatial scales into assessments of the efficacy of riparian management as a complement to more detailed local scale riparian assessments in situ. Our findings highlight the value of even small patches of riparian vegetation in an otherwise extensively disturbed landscape in supporting biodiversity of both terrestrial and freshwater invertebrates and emphasize the need to consider multiple spatial scales in riparian management strategies which aim to mitigate human impacts on biodiversity in stream-riparian networks.
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An examination of the impacts of invasive woody vegetation on grassland birds and waterfowl

An examination of the impacts of invasive woody vegetation on grassland birds and waterfowl

All of the hypothesized reasons why trees might be detrimental to nesting ducks (e.g., providing necessary or preferred habitat, or altering movement or foraging patterns of certain predators) seemed reasonable and consistent with widely accepted ideas about predator ecology and nest survival (Phillips et al. 2003, Grant et al. 2004, Grant et al. 2006), and we were surprised that we did not find at least a weak negative effect of woody vegetation on nest survival rates. Given the wide array of predators that will eat duck eggs, management activities targeted at any single predator species or group (i.e., woodland predators) may have little effect on overall predation rate given compensatory predation by other species (Greenwood 1986, Greenwood et al. 1998). Active removal of shelterbelts in Wisconsin grasslands caused a shift in the types of nest predators and an increase in breeding density, but no overall change in nest survival rates for grassland songbirds (C. Ribic, USGS Wisconsin Cooperative Wildlife Research Unit, personal communication). Renfrew and Ribic (2003) found that woodland predators traveled up to 200 m into grassland habitat to depredate nests, and tree removal at the level of individual WPAs (median size 63 ha) may be ineffective at altering foraging behavior of local predators.
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