Vegetation Community Structure, Composition and Distribution Pattern in the Zaraninge Forest, Bagamoyo District, Tanzania

2009 ◽  
Vol 98 (2) ◽  
pp. 223-239 ◽  
Author(s):  
Cosmas Mligo ◽  
Herbet Lyaruu ◽  
Henry Ndangalasi ◽  
Rob Marchant
2021 ◽  
Vol 13 (6) ◽  
pp. 3569
Author(s):  
Hua Cheng ◽  
Baocheng Jin ◽  
Kai Luo ◽  
Jiuying Pei ◽  
Xueli Zhang ◽  
...  

Quantitatively estimating the grazing intensity (GI) effects on vegetation in semiarid hilly grassland of the Loess Plateau can help to develop safe utilization levels for natural grasslands, which is a necessity of maintaining livestock production and sustainable development of grasslands. Normalized difference vegetation index (NDVI), field vegetation data, and 181 days (one goat per day) of GPS tracking were combined to quantify the spatial pattern of GI, and its effects on the vegetation community structure. The spatial distribution of GI was uneven, with a mean value of 0.50 goats/ha, and 95% of the study area had less than 1.30 goats/ha. The areas with utilization rates of rangeland (July) lower than 45% and 20% made up about 95% and 60% of the study area, respectively. Grazing significantly reduced monthly aboveground biomass, but the grazing effects on plant growth rate were complex across the different plant growth stages. Grazing impaired plant growth in general, but the intermediate GI appeared to facilitate plant growth rate at the end of the growing seasons. Grazing had minimal relationship with vegetation community structure characteristics, though Importance Value of forbs increased with increasing GI. Flexibility in the number of goats and conservatively defining utilization rate, according to the inter-annual variation of utilization biomass, would be beneficial to achieve ecologically healthy and economically sustainable GI.


Author(s):  
Dandi Saleky ◽  
Simon P.O Leatemia ◽  
Yuanike Yuanike ◽  
Irman Rumengan ◽  
I Nyoman Giri Putra

Gastropods is an important organism that commonly found inhabiting the rocky intertidal area. Distribution pattern of this species is influenced by various factors such as population history, microhabitat, predation and a complex interactions between oceanographic dynamics and ecological features. This study aims to compare the temporal distribution pattern of gastropods at two different rocky intertidal area. This research was conducted at the rocky intertidal area of Amban and Nuni, North Manokwari District, West Papua. Data collection was performed during the daylight and night in April and June 2012 using systematic sampling method. The results showed that both physical and chemical factors are suite for supporting gastropods life. Furthermore, these factors seem to have an impact on gastropod zoning patterns observed in the study area. The similarity index values ​​indicate that the similarity of gastropod species between the two locations is low, which means that the species of gastropods found in each location is quite different. The community structure of gastropod at the study area is stable. In addition, we found that the gastropods diversity were higher during the night than the daylight because gastropods are classified as a nocturnal animals. Key Words: Gastropod; Rocky Intertidal; Community Structure; Nocturnal


2017 ◽  
Author(s):  
Lili Li ◽  
Chengzhang Zhao ◽  
Tingjun Zhang ◽  
dawei wang ◽  
yuxing li ◽  
...  

Species interactions are often context-dependent and complex, such as the grasshopper community and phytoecommunity. The adoption of grasshopper abundance and vegetation community was determined by topographical heterogeneity. However, it remains vague about how vegetation community, such as coverage abundance and height, influence the spatial distribution pattern of grasshopper abundance at the altitude gradient. Using Geostatistical methods in natural grassland of the upper reaches of Heihe River to quantitatively study the relationship of spatial correlation. A 3 years investigation was shown that 3149 grasshoppers were collected, belonging to 3 families, 10 genera, and 13 species. The semivariable function of grasshopper abundance and vegetation community followed a nonlinear model. Meanwhile, horizontal distribution of two communities was a clear flaky and plaque distribution pattern, especially at the altitude gradient. The abundance of grasshoppers is opposite to the height and coverage of vegetation and the overall followability of coverage, while the local following is consistent. Such as grasshopper abundance, the above 2750m sample with the opposite trend, the following areas are consistent. Finally, grasshoppers have the different choice on different vegetation characteristics in different directions, formed of specific trend characteristics; and the spatial distribution trend is different even with the same community indicators, formed of embedded striped patches structure.


2019 ◽  
Vol 10 (2) ◽  
pp. 78
Author(s):  
Brenda V.A. Lahiwu ◽  
Rose O.S.E. Mantiri ◽  
Ferdinand F. Tilaar ◽  
Laurentius Th. X. Lalamentik ◽  
Ruddy D. Moningkey ◽  
...  

This study aims to determine the type and community structure of zooplankton in the Tongkaina seagrass aquatic ecosystem. Sampling was carried out at 3 location points using plankton nets. Plankton net was drawn along 50 meters from the sea towards the beach. There are 14 genera of zooplankton in the morning and 17 genera in the afternoon. The total density of zooplankton in the morning was 0.064 individual/l , and in the afternoon 0.114 individual/l. The highest density of zooplankton in the morning is Limacina and in the afternoon, Calanus. The zooplankton Diversity Index (H ') in the morning is 2.5907 and in the afternoon is 2.7321, indicating that the diversity level is less diverse. Morning uniformity (e) zooplankton index was 0.5614 and in the afternoon 0.5267, showed that the distribution pattern of zooplankton was moderate. The zooplankton dominance (C) index in the morning was 0.0783 and in the afternoon 0.0720. This shows that there is no dominant genus. Water conditions fall into the good category due to the temperature, salinity, and pH that are quite stable and are still within the limits of feasibility for zooplankton life.    Keywords: Zooplankton, Community Structure, Seagrass, Tongkaina Waters.Keywords: Zooplankton, Community Structure, Seagrass, Tongkaina Waters  ABSTRAKPenelitian ini bertujuan untuk mengetahui jenis dan struktur komunitas zooplankton yang ada di ekosistem perairan lamun Tongkaina. Pengambilan sampel dilakukan pada 3 titik lokasi dengan menggunakan jaring plankton.Plankton net ditarik sepanjang 50 meter dari laut ke arah pantai. Terdapat 14 genus zooplankton pada waktu pagi dan 17 genus pada waktu sore. Kepadatan total zooplankton pada waktu pagi hari 0.064 ind/l dan sore hari 0.114 ind/l. Kepadatan relatif zooplankton yang tertinggi pada pagi hari yaitu Limacina dan pada sore hari yaitu Calanus. Adapun Indeks Keanekaragaman (H’) zooplankton pada pagi hari sebesar 2.5907 dan sore hari sebesar 2.7321, menunjukkan bahwa tingkat keanekaragaman kurang beragam. Indeks Keseragaman (e) zooplankton pada pagi hari sebesar 0.5614 dan pada sore hari 0.5267, menunjukkan bahwa pola sebaran zooplankton sedang. Indeks Dominansi (C) zooplankton pada waktu pagi hari sebesar 0.0783 dan sore hari 0.0720. Hal ini menunjukkan bahwa tidak ada genus yang dominan. Kondisi perairan masuk dalam kategori baik dikarenakan suhu, salinitas dan pH cukup stabil dan masih berada dalam batas kelayakan bagi kehidupan zooplankton.Kata kunci: Zooplankton, Struktur Komunitas, Lamun,  Perairan Tongkaina.


2021 ◽  
Author(s):  
Lili Li ◽  
chengzhang zhao ◽  
xiawei zhao ◽  
dawei wang ◽  
yu li

Abstract Species interactions are often context-dependent and complex, such as the grasshopper community and phytoecommunity. The adaption of grasshopper abundance and plant community were determined by topographical heterogeneity. However, it remains vague about how vegetation community, such as coverage, abundance and height, influence the spatial distribution pattern of grasshopper abundance at the altitude gradient. The geostatistical methods were used in natural grassland of the upper reaches of Heihe River to quantify the relationship of spatial correlation. A 5-years investigation shown that 3149 of grasshoppers was collected,belonging to 3 families, 10 genera, and 13 species. The semivariable function of grasshopper abundance and vegetation community followed a nonlinear model. Meanwhile, horizontal distribution of two communities was a clear flaky and plaque distribution pattern, especially at the altitude gradient. The abundance of grasshoppers is opposite to the height and coverage of vegetation and the overall follow ability of coverage, while the local following is consistent. Such as grasshopper abundance, the above 2750m sample with the opposite trend, the following areas were consistent. The grasshoppers exhibited the varieties on vegetation characters among all directions. On the different habits, the spatial distribution formed uniform trends; meanwhile, on the same, the trends diversified with altitude gradient, formed embedded striped patches structure.


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