Marginalised herders: social dynamics and natural resource use in the fragile environment of the Richtersveld National Park, South Africa

This research article published by Elsevier B.V., 2018In the contractual Richtersveld National Park (RNP), park officials and neighbouring communities jointly manage resources, with the aim to harmonize biodiversity conservation and human land use. Our socio-ecological approach compared herding practices and livelihoods of 36 livestock owners and 35 hired herders inside and outside RNP, and further assessed soil quality and vegetation characteristics under different livestock grazing patterns and access to natural resources. Hired herders were mainly in charge of animal movement patterns but were not included in formal agreements, which negatively impacted on natural resource management, livelihoods, animal well-being and communication amongst stakeholders. Soil properties and vegetation were generally negatively affected through grazing and herding practices in this fragile semi-arid biodiversity hotspot that encompasses many endangered and endemic species. Our research highlights the complex social relationships and dynamics between diverse stakeholders engaged in the contractual park and accentuates the need to improve herders’ social and economic status

Impacts of alien invasive Parthenium hysterophorus on flower visitation by insects to co-flowering plants

The exotic invasive plant Parthenium hysterophorus is invading many tropical habitats. While much work has been done on its interactions with other native plants, little is known about its interaction with insect floral visitors and how it impacts pre-existing pollination networks when it invades a site. We carried out surveys on sites with and without P. hysterophorus (invaded and uninvaded, respectively) to investigate its impact on plant–pollinator interactions with two common indicator or target plants (Ocimum gratissimum and Ageratum conyzoides) in Tanzania. During multiple 15 min observation periods in quadrats, the number of arriving flower visitors, duration of visits and visitation rate were measured and compared between sites. Visitation networks of flower visitors were developed by observing flower visitor taxonomic groups and plants visited across both invasion categories. Parthenium hysterophorus was heavily visited by a diversity of flies as taxonomic groups. Indicator plants received fewer flower visitors overall in the invaded site, implying P. hysterophorus may be disrupting pollen flow. Foraging behaviour and flower visitation by Apis mellifera and flies on target plants were particularly negatively affected in the invaded quadrats. Flower visitation rate to target plants was significantly lower in invaded quadrats than in uninvaded quadrats. This study supports work in other parts of the world demonstrating that invasive species can strongly disrupt pollination networks. By attracting flower visitors that could otherwise serve as pollinators of native plant species, P. hysterophorus which is rapidly spreading in eastern African ecosystems could have complex deleterious effects on the wider ecosystem

Diet of the Common Warthog (Phacochoerus africanus) on Former Cattle Grounds in a Tanzanian Savanna

In otherwise nutrient-poor savannas, fertile vegetation patches are particularly attractive to ungulates because of the higher-quality food they provide. We investigated forage plants and diet of the common warthog (Phacochoerus africanus) on an abandoned cattle ranch in coastal Tanzania. The forage grasses of highest nutritional quality occurred in former paddock enclosures (bomas) where cattle had been herded at night. In the dry season, grass samples from bomas contained approximately 4 times as much nitrogen and phosphorus as those of the surrounding vegetation. δ15N values of soil and plants also were highest in bomas and decreased significantly with distance, and high δ15N values in feces suggest that warthogs preferentially fed in the vicinity of the former bomas. δ13C values of warthog feces indicate that warthogs ingested on average 83% (77-98%) C4 grasses, with this proportion varying regionally but not seasonally. We conclude that, for medium-sized selective grazers such as warthogs, bomas represent attractive feeding grounds. We also hypothesize that by promoting nutrient turnover in these patchily distributed areas, grazing animals help to maintain them as sources of high-quality forag

Modeling Boran cattle populations under climate change and varying carrying capacity

This research article published by Elsevier, 2017Cattle populations in semiarid rangelands are currently facing severe threats due to erratic rainfall and increasing drought frequencies, leading to poor vegetation quality and a consecutive cattle population decline. However, little is known about how particular sex- and age-cohorts of cattle respond to these environmental threats and on how sales influence population trajectories. In the Borana rangelands, southern Ethiopia, much detailed information is available on the Boran cattle (Bos indicus) population demographics, a special breed, which is highly adapted to semiarid environmental conditions. We collected data on Boran cattle demographic and environmental factors such as carrying capacity, market values, and herderś management decisions. We generated stochastic models and assessed the future development of cattle population trajectories under four different drought scenarios. We analyzed changes in age- and sex-cohorts of cattle populations by introducing different drought frequencies and their effect on vital rates, carrying capacity, and sales. We calibrated the model on the basis of a 12-year data set of a neighboring Boran cattle group. In our population model, the cattle numbers significantly declined after 18 years under the higher drought frequency scenarios (scenarios 3 and 4) while numbers remained high over 100 years for the lower drought frequency scenarios 1 and 2. The sale of senescent and adult females most strongly (77%) affected population trajectories, and model outcomes were most sensitive to sale rates of senescent, adult, and juvenile females compared to vital rates and male sale rates of the population. Management should focus on lowering herd crashes through increasing sale of mature males, which increases feed availability to females during drought years in the Ethiopian Rangelands. Drought early-warning systems and market information must be strengthened so that pre-planned selling of cattle can be realized for a sustainable use of the animal resource

Ethnobotany of Oyster nut ( Telfairia pedata) in Northern Tanzania

This research article was published in Journal of Biodiversity and Environmental Sciences, Volume 20, 2022.Telfairia pedata (Sims) Hook is an important native climber plant commonly grown in East Africa. It bears nuts which are eaten either raw or cooked and is consumed mostly by expectant mothers, and as cooking oil. The survey was conducted between September 2019 to February 2020 in Sambaa, Meru, and Pare communities of Lushoto, Bumbuli, Arumeru and Same Districts, Northern Tanzania to assess the ethnobotany of T. pedata from a sample of 346 respondents using semi-structured questionnaires. Results indicate that, 21% of respondents used T. pedata for cooking with other staple foods while 18% claimed that the nuts are used by pregnant and lactating mothers for medicinal and breast milk stimulation and nine (9) percent indicated that the nuts are used for cultural and ritual purposes. Despite its importance, the cultivation of T. pedata in the study area is declining and the gap why such decline is experienced needs to be answered in further studies. Secondly, respondents within the 36-50 age groups reported the greatest diversity of uses of T. pedata 51% compared with those aged below 36 years old 21% signifying that the traditional knowledge known by younger aged groups may be declining. Thus, this gap of traditional knowledge between the groups should be addressed in order to improve utilization and conservation of this seriously declining yet important nut in the study area and other places of Tanzania

Rainfall, fire and large-mammal-induced drivers of Vachellia drepanolobium establishment: Implications for woody plant encroachment in Maswa, Tanzania

This research article published by John Wiley & Sons, Inc., 2021Worldwide, open grass areas of savannah ecosystems are being transformed into shrubland. This woody plant encroachment is likely a result of factors such as rainfall, fire and secondary dispersal by ungulate herbivory. However, few experiments have been conducted to disentangle and quantify the role of these factors for seed germination in savannahs. We assessed in situ germination success of Vachellia drepanolobium seeds under simulated rainfall variability patterns, fire treatments and dung experiments in Maswa Game Reserve, Tanzania. Fire reduced seed germination by more than 13%, whereas germination in buffalo and elephant dung increased by 1% and 3% respectively. Additionally, intermediate simulated rainfall was more beneficial for seedling emergence success than large, infrequent simulated rainfall amounts, while shoot growth was twice as high under frequent and intermediate simulated rainfall treatments than under large infrequent simulated rainfall. Our results provide insights that bush fires, drought stress, and large rainfall events can suppress V. drepanolobium seedling emergence and growth. Hence, bush encroachment may be linked to management practices such as fire regimes and climatic conditions, i.e., frequent low rainfall conditions. Our results can help predict future patterns of encroachment under varying rainfall and fire events

Growth performance of the neglected crop Telfairia pedata across elevation and climate gradients in Northern Tanzania

This research article published by Elsevier B.V., 2022Herbaceous vines, including the neglected crop Telfairia pedata, play a key role in small-holder livelihoods of Eastern Africa. Despite this species’ importance in enhancing agro-biodiversity, little is known about its distri- bution and growth performance in relation to environmental variables. We collected biophysical and environ- mental data, i.e., on climate and elevation, for 346 T. pedata vines across four districts of Northern Tanzania from September, 2019, to February, 2020. The four sites included Same, Lushoto, Muheza and Arumeru districts. We found that plants of T. pedata were mainly grown in elevations ranging between 900 to 1800 m above sea level with annual rainfall regimes of 1000 to 1400 mm. We recorded large abundance of T. pedata in Lushoto (46%) and Arumeru (28%) and observed that the number of fruits and fruit diameter were both positively correlated with elevation across the study districts. There was a significant effect of elevation on number of seeds, with Same district having more seeds across the studied districts. Rainfall had a significant effect on fruit diameter and number of seeds in the study districts. Furthermore, the tree species Albizia schimperiana was most commonly (in 40% of the cases) associated with T. pedata, followed by Persea americana (14%), and Croton macrostachyus (9%). We highlight that mountainous regions are ideal for this highly nutritious crop, and that native trees are of high importance for enriching this vine to current agro-ecosystems. Our findings will increase awareness on the importance of raising T. pedata crop, livelihood diversification, and increasing biodiversity through production of this orphan crop in small-holder farms. 1. Introduction Telfairia pedata (Smiths ex Sim) Hook or oyster nut belongs to Cur- cubitaceae family, which includes over 700 species and approximately 90 genera (Okoli and Mgbeogu, 1983; Odiaka et al., 2008; Chiamaka et al., 2020). It is a herbaceous woody vine and dioecious that bears squash-like fruits with large and nutritious oily seeds, is perennial and can withstand drought to some extent (Onovo et al., 2010; Ifeanyi-Obi et al., 2013), (Fig. 1). Telfairia pedata is mostly grown for its oilseeds in Tanzania including Zanzibar Island, and other African countries including Angola, Mozambique, coast of Kenya, Uganda and Nigeria (Schippers, 2000; Odiaka et al., 2008; Odiaka and Odiaka, 2011; Are- gheore, 2012). The nuts are highly valued by East Africa natives and are in great demand by breastfeeding mothers (Fubara-Manuel et al., 2012; Nwonuala and Obiefuna, 2015). These oilseeds are related to pumpkin seeds (Cucurbita moschata) which are also highly important for their therapeutic and functional (nutraceutical) values (Dotto & Chacha, 2020). Telfairia pedata nuts are mostly eaten raw or boiled, roasted for confectionery or grounded into a thick paste for use in staple meals such as soup thickening (Odiaka et al., 2008; Alegbejo, 2012). It contain protein, fat, carbohydrates, oleic acid, linoleic acid, stearic acid, pal- mitic acid, minerals including phosphorus (P), magnesium (Mg), po- tassium (K), iron (Fe) and calcium (Ca) (Aregheore, 2007; Mwakasege et al., 2021). In some cases, Telfairia species provide substantial cash income to small rural farm families and for biodiversity conservation (Akoroda, 1990; Alegbejo, 2012; Chukwurah et al., 2015). However, despite its household income generation, nutritional and environmental value, the cultivation of this crop in Tanzania has been neglected, and little is known about its distribution, growth performance and constraints. The climber grows well in presence of hard wood trees or wooden made structures, and it is regarded as an important component of the rich * Corresponding author. E-mail address: [email protected] (P.F. Shayo). Contents lists available at ScienceDirect Trees, Forests and People journal homepage: www.sciencedirect.com/journal/trees-forests-and-people https://doi.org/10.1016/j.tfp.2022.100216 Received 30 August 2021; Received in revised form 25 January 2022; Accepted 3 February 202

Environmental factors and non-chemical methods to suppress growth of the invasive plant Gutenbergia cordifolia

A research article was published by Acta Oecologica Volume 119, August 2023Little is known about preferred environmental conditions and non-chemical control of invasive Gutenbergia cordifolia. We assessed the effects of different A. annua crude extract concentrations, synthetic herbicide (glyphosate), fire regime and shade to G. cordifolia germination, shoot and root dry biomass, seedling height and leaf chlorophyll. High concentrations (75%) of A. annua crude extracts significantly reduced germination percentage of G. cordifolia by 25% (F2,4=77.2, p < 0.001), and suppressed shoot and root dry biomass (F2,4 = 80.3, p < 0.001; F2,4=46.104, p < 0.001, respectively) as well as seedling height and leaf chlorophyll (F2,4 = 12.02, p < 0.002; F2,4 = 15.9, p < 0.001), respectively. Medium temperature (60 °C) and long exposure time (5 min) significantly increased G. cordifolia germination percentage (F2,7 = 32.6, p < 0.001) while extreme temperatures (≥150 °C) at both (1 min) short and (5 min) long exposure time completely suppressed germination of G. cordifolia. Under high shade, while germination percentage was a third that of other treatments (F 2, 4 = 20.9, p = 0.008), mean germination took twice as long (F2, 4 = 17.9, p = 0.010) and shoot fresh biomass was reduced by half (F 2, 4 = 16.92, p = 0.004). Shoot and root dry biomass were reduced to more than a third under high shade, seedling height reduced to half but leaf chlorophyll content was not affected (F 2,4 = 6.3, p = 0.030; F 2,4 = 9.1, p = 0.020; F 2,4 = 18.3, p = 0.003; F 2,4 = 3.02, p = 0.120, respectively). We suggest using A. annua as a potential bio-herbicide and highlight considering fire and shade as suppressor tools to control G. cordifolia, but first include in-situ trials to assess their impacts to both native plants and animals

Mammalian wildlife diversity in rubber and oil palm plantations.

This research article published by CABI, 2016In the face of globally diminishing natural habitats in biodiversity-rich regions, agricultural landscapes around protected areas have increasingly gained importance as extended habitat for wildlife species. Rubber (Hevea brasiliensis) and oil palm (Elais guineensis) plantations are two of the dominant land-use systems in Southeast Asia that have seen a tremendous expansion over the last decades. Despite far-reaching ecological consequences of these intensively cropped monocultures on natural ecosystems, relatively little is known about their utilization by wildlife populations. With this review we want to give an overview of mammalian diversity in rubber and oil palm plantations with reference to human-wildlife conflicts occurring as a result of overlapping resource use. We searched the literature for studies on wild mammalian diversity in rubber and oil palm plantations and found 17 publications. We considered 29 additional publications that provided information on single species in such plantations. We discuss the potential of 'wildlife-friendly' farming for mammalian assemblages in plantations and its importance in the case of rubber and oil palm production. Our review showed that most wild mammal species found in these plantations were likely to be visitors that use cultivated landscapes as fringe habitat but some adapted well to plantations and few even became resident. We conclude that although plantations in the tropics and subtropics cannot substitute for forests and the preservation of natural habitats is indispensable, the reality of ongoing forest degradation and transformation into plantations will make wildlife-friendly farming a key strategy in maintaining mammalian diversity, particularly in land-use matrices surrounding natural habitats

Land Use Land/Cover Change Reduces Woody Plant Diversity and Carbon Stocks in a Lowland Coastal Forest Ecosystem, Tanzania

This research article was published in the Journals of Sustainability Volume 14, Issue 14, 2022The East-African lowland coastal forest (LCF) is one of Africa’s centres of species endemism, representing an important biodiversity hotspot. However, deforestation and forest degradation due to the high demand for fuelwood has reduced forest cover and diversity, with unknown consequences for associated terrestrial carbon stocks in this LCF system. Our study assessed spatio-temporal land use and land cover changes (LULC) in 1998, 2008, 2018 in the LCF ecosystem, Tanzania. In addition, we conducted a forest inventory survey and calculated associated carbon storage for this LCF ecosystem. Using methods of land use change evaluation plug-in in QGIS based on historical land use data, we modelled carbon stock trends post-2018 in associated LULC for the future 30 years. We found that agriculture and grassland combined increased substantially by 21.5% between the year 1998 and 2018 while forest cover declined by 29%. Furthermore, forest above-ground live biomass carbon (AGC) was 2.4 times higher in forest than in the bushland, 5.8 times in the agriculture with scattered settlement and 14.8 times higher than in the grassland. The estimated average soil organic carbon (SOC) was 76.03 ± 6.26 t/ha across the entire study area. Our study helps to identify land use impacts on ecosystem services, supporting decision-makers in future land-use planning