Effects of agriculture on bees diversity in Mawingo, Mweka and Kilimanjaro National Park

Texte Universitaire , 2021 , 24 Pages

Sciences de l'Environnement

The research will offer information on bees and the commencement of future actions on conservation of bees in Tanzania and the world at large.

In order to provide good pollination service at high rate, Bee needs a favorable environment and or area that is free from agricultural products such as pesticides, fertilizers also free from diseases and trampling which will provide a pollination service that is effective. In addition the environment should not be overly cost for bee diversity.

Increase in human population has led to the high demand for food; the high demand for food by human has led to the ongoing increase in farm size with specialization leading to the reduction of natural vegetation areas for food production.

If the agricultural areas will continue to be treated with pesticides and fertilizers, farmers will be wasting their time because the bee diversity will keep on declining and later on the pollination service will be poorly performed that will result to poor productivity of crops. Also bees suffering can lead to a total disappearance of bees hence lack pollination services completely.

Keywords: Agriculture, Diversity, Biodiversity, pollinators, Intensive

ABSTRACT

Unmatched growth in human population has required the intensification of agriculture, whereby there is an ongoing increase in farm size with specialization so as to enhance crop productivity to satisfy the unlimited human wants, but this is being achieved at the major cost to biodiversity. This study was initiated to investigate the effect of agriculture on bee diversity in three (3) sites located in Kilimanjaro region. Ten (10) quadrats of 10 x 10 m were systematically positioned in each study site and in each quadrant a pan trap sampling method was used to sample bees. The bee’s diversity was calculated for each site, the results showed negative effect of agriculture on bee’s diversity as high diversity was found in natural vegetation (Kilimanjaro national park) followed by Mweka village which is Mid intensive agriculture and finally low bee’s diversity at Mawingo coffee plantation which is intensive agriculture, this indicates that as agricultural intensification increases bee diversity decreases. Farmers should be encouraged to restore pollinator’s friendly habitat whereby the restoration of plant biodiversity within and around the crop field which can be done by providing flowers around and within the crop field which can likely improve habitat for bees and thus enhancing pollination services in agroecosystems.

Keywords: Agriculture, Diversity, Biodiversity, pollinators, Intensive

1.0. INTRODUCTION

1.1. Background information

Insects, particularly bees, are the primary pollinators of most agricultural crops and wild plants(Potts et al., 2010). The major functional role of pollinators is the maintenance of both wild plant communities which is a key ecosystem service in terrestrial ecosystems (Ashman et al., 2004) and agricultural productivity (Ricketts et al., 2008).

There is about 120,000 species of bees (Mcmullen & Lysyk, 1995) which are known in the world, However, in Africa only 12,000 species are known (Js, 2002).The honeybee is a well- known bee species due to its value of honey production(Some Interesting Facts About Bees, n.d.) ,also Farmers have highly regarded bees for their pollination services though it is not known to what extent they are recognized in the past (Eardley, Gikungu, & Schwarz, 2009) .The wild bees are ignored and very little is known about them despite of their ecosystem service importance.

Globally, bees predominantly managed to enhance agricultural production, and there is a clear evidence for severe regional decline of the bee (Potts et al., 2010).It has been seen that large crop fields threaten pollination where by increased crop production has been mainly based on the use of quality seed, pesticides and fertilizers with little regard to honeybee as an agricultural eco­service that may require protection (Eardley et al., 2009)

There is a decline of pollinators as documented in two Western European countries (Britain and the Netherlands) by comparing data obtained before and after 1980 (Biesmeijer et al.,. 2006).They assessed agricultural practices in terms of agricultural inputs such as nitrogen fertilizers and pesticides ,and they showed the negative effect of agricultural intensification on species richness, abundance and diversity of bees (Le Féon et al., 2010) There is evidence that pollinator diversity and pollination service decreases with increasing agricultural intensification(Steffan- et al., 2008)

In Africa, specifically South Africa has also tried to address the problem that agriculture has a greater impact to pollinators through the modification of pollinators habitats and the use of agricultural chemicals (pesticides, herbicides and fertilizers) (Annalie Melin, Melin, Rouget, & Midgley, 2014)

In Tanzania, there are few research conducted to look on the effect of agricultural activities on bee diversity hence little information is known about bee diversity in relation to agricultural activities.

1.2. Problem Statement and justification

In order to provide good pollination service at high rate, Bee needs a favorable environment and or area that is free from agricultural products such as pesticides, fertilizers also free from diseases and trampling which will provide a pollination service that is effective. In addition the environment should not be overly cost for bee diversity.

There is a decline in pollinators such as bees due to habitat loss, habitat fragmentation, alien invasive species, agricultural intensification and climate change(Potts et al., 2016;Winfree, 2010).

Increase in human population has led to the high demand for food; the high demand for food by human has led to the ongoing increase in farm size with specialization leading to the reduction of natural vegetation areas for food production (Deguines et al., 2014)

The environment now is disturbed largely by agricultural activities which tend to extend even far to the natural areas (Schüepp, Rittiner, & Entling, 2012) which leads to loss of habitat by bees due to trampling done in agriculture and also decline of bees due to agricultural products like pesticides and fertilizers. Expansion of farms has led to agricultural areas being used as habitat for bees which are now a threat to bee diversity due to the chemicals used.

If the agricultural areas will continue to be treated with pesticides and fertilizers, farmers will be wasting their time because the bee diversity will keep on declining and later on the pollination service will be poorly performed that will result to poor productivity of crops (Garibaldi, Requier, & Rollin, 2017) Also bees suffering can lead to a total disappearance of bees hence lack pollination services completely.

However, less has been done on the effect of agriculture on bee diversity at Mawingo, Mweka and KINAPA. Therefore with this gap in knowledge these study aim to determine the effect of agriculture on bee diversity.

The research will offer information on bees and the commencement of future actions on conservation of bees in Tanzania and the world at large.

1.3. Objectives

1.3.1. General objective

- To determine the effect of agriculture on bee diversity.

1.3.2. Specific objective

- To identify bee species in different agricultural intensity
- To determine the bee abundance in different agricultural intensity
- To determine bees diversity in different agriculture intensity

1.4. Hypothesis

Alternative hypothesis

- (Ha) 1 : Agricultural practices have significant difference on bee abundance.
- (Ha) 2: Agricultural practices have significant difference on bee diversity.

2.0 . METHODOLOGY

2.1 Study area description

2.1.1 Geographical Location

The study area, ‘Kibosho Mweka Village’ lies between 37°15' and 37°21‘ E and 3°03‘ to 3°20‘ S with elevation of 800-2000m.a.s.l. This study based on Mawingo plantation area with elevation of 1325m.a.s.l, followed by Mweka village with elevation of 1348m.a.s.l and KINAPA area (Pongo) with elevation of 1338m.a.s.l.

2.1.2 Climate

There is double rain seasons at Kibosho Mweka area, long rains often start in March to July and the shorter rains start from November to January. The annual rainfall range is 1000 to 1700 mm but it can rise up to 2500 mm depending on respective elevation. The temperature varies seasonally, ranging between 17°C and 30°C throughout the year. The dry months are from August to October and the cool months are from June to August.

2.1.3 Vegetation

Characterized by different vegetation types including tree-crop plantations, riverine vegetation, shrubs, and Montane forest which are all found along the southern slopes of Mount Kilimanjaro. Between 700-2000 m above the sea level, coffee and banana plantation dominates, with other food crops such as maize, yams and beans. Montane forest lying between 1400-1800 m above the sea level, whereby below 1800 m above the sea level the dry montane forest exists and between 1400-1600 m above the sea level, sub- montane riverine forest occurs (Hemp, 2006).

This image got removed by the editiorial team due to copyright reasons.

Figure 1: A map showing the study area

2.2. Sampling design and data collection

2.2.1 Sampling site

Three sites were selected basing on their land uses, Intensive agricultural area was selected at Mawingo coffee plantation with an altitude of 1325 metres above sea level, mid intensive agricultural area was selected at Mweka village (Ursula) with an altitude of 1348 metres above the sea level in this area there were mixed farming of maize and beans as well as human settlements and last area was natural vegetation which was Kilimanjaro national park at Pongo area with an altitude of 1338 metres above the sea level.

2.2.2 Sampling techniques

Pan trap method

In each study site, four clusters each containing three pan traps of three different UV reflecting colors (yellow, blue and white) was used to passively collect bees for estimating their diversity and abundance. Four clusters of pan traps (two with 35 cm and two with 120 cm tall poles) was positioned diagonally from each other on two 10m parallel transects with interspace distance of 7m (Figure 2). Bees were sampled in different land uses. On each transect, two pan trap clusters were positioned 7m apart in such a way that 1.5 m were left at the opposing ends of the transect (Figure 2). On each study site, the four clusters of pan traps were left to collect bees for 48 hours after which water was emptied and samples were collected. A mixture of ethanol and soapy water were filled in pan traps where 70% ethanol was used to preserve the bees after been traped, and soapy water in the pan traps was essential for breaking the surface tension of water and creates slippery texture to avoid bees escape. These pan traps were set based on each of 30 quadrats.

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• Auteur: Erick Swai (Auteur)
• Année de publication: 2021
• Pages: 24
• N° de catalogue: V1139045
• ISBN (ebook): 9783346513052
• ISBN (Livre): 9783346513069
• Langue: anglais