The tropical forest kapok tree occurs widely in urban environments, dispersing thousands of floss during the fruiting season. However, its seedlings are rarely seen around human settlements, raising questions on what ...The tropical forest kapok tree occurs widely in urban environments, dispersing thousands of floss during the fruiting season. However, its seedlings are rarely seen around human settlements, raising questions on what factorsmight be limiting its recruitment. We examined the pattern of floss release, seed fall post-dispersal and influences of watering frequency on germination ofCeiba pentandraseeds. Evening,overall, was associated with a significantlyhigher rate and quantity of floss release (p= 0.0001) than were mid-day and morning, correlating well with the speed of wind across the day (rh = 0.666,p= 0.001). Mean dispersal quantity differed significantly between the individual sampled trees, in which the highest dispersal was recorded from trees located in relatively open areas and the lowest was recorded in closed stand trees. Seed fall was higher within100 mdistances than seed fall farther away from dispersing trees, depending on the microsites and weather conditions. Germination started on day 5 onwards and only 15.67% of sown seeds germinated. Watering frequency strongly influenced seed germination while local human activities determined fate of dispersed seeds. We conclude that recruitment ofC. pentandraspecies in the study area may have been limited by environmental and human factors operating at various local and spatial scales.展开更多
Introduction:Rangelands are important source of pasture for livestock in Kenya since time immemorial to pastoral households.However,seasonality on forage availability has been a big challenge in meeting animals’feed ...Introduction:Rangelands are important source of pasture for livestock in Kenya since time immemorial to pastoral households.However,seasonality on forage availability has been a big challenge in meeting animals’feed requirements.This demands harvest and storage of pastures for use during dry seasons.Hay making has been done to bridge this forage deficit periods.However,hay quality in the rangelands is affected by curing methods,phonological stage at harvest,and the storage duration.We therefore evaluated the effect of field curing and storage duration on the quality(Crude Protein(CP))of hay from six rangeland grasses in Kenya.Methods:The grasses evaluated are Chloris roxburghiana,Eragrostis superba,Enteropogon macrostachyus,Cenchrus ciliaris,Chloris gayana,and Sorghum sudanense.These grasses are the common species in the rangelands of Kenya and have been promoted in the past for hay making and reseeding interventions.The grasses were harvested at the mature flowering stage(12 weeks phenological stage),which is a period that provides high biomass without much effect on quality as practiced in the study area.The grasses were then cured in the field for 1,2,and 3 days before baling and stored indoors for 12,24,and 36 weeks.Samples were taken for CP content determination at the three periods following Macro-Kjeldahl Method.Results:There was significant decline(p≤0.05)in crude protein content in all the grass species with storage periods.Curing period did not affect the CP content for all the species at a given storage period;however,3 days curing changed the hay color from green to brownish which reduces palatability and consequently reduced feed intake.Storage period of over 12 weeks adversely lowered CP to less than 6% for all the species which is the required minimum level for animal under production and maintenance.S.Sudanense had significantly higher decline in CP after 24 weeks storage compared to the other species.Conclusions:Therefore,hay from the six grass species harvested at mature flowering stage(12-week phonological stage)and stored longer than 12 weeks supplies the animals with low CP.Also,to maintain palatability,1-2 days curing is recommended for the six grass species.展开更多
文摘The tropical forest kapok tree occurs widely in urban environments, dispersing thousands of floss during the fruiting season. However, its seedlings are rarely seen around human settlements, raising questions on what factorsmight be limiting its recruitment. We examined the pattern of floss release, seed fall post-dispersal and influences of watering frequency on germination ofCeiba pentandraseeds. Evening,overall, was associated with a significantlyhigher rate and quantity of floss release (p= 0.0001) than were mid-day and morning, correlating well with the speed of wind across the day (rh = 0.666,p= 0.001). Mean dispersal quantity differed significantly between the individual sampled trees, in which the highest dispersal was recorded from trees located in relatively open areas and the lowest was recorded in closed stand trees. Seed fall was higher within100 mdistances than seed fall farther away from dispersing trees, depending on the microsites and weather conditions. Germination started on day 5 onwards and only 15.67% of sown seeds germinated. Watering frequency strongly influenced seed germination while local human activities determined fate of dispersed seeds. We conclude that recruitment ofC. pentandraspecies in the study area may have been limited by environmental and human factors operating at various local and spatial scales.
基金supported by the National Irrigation Board(NIB)Kenya,Government of Kenya through the National Council of Science,Technology and Innovation(NACOSTI),German Academic Exchange Service(DAAD),and the Centre for Sustainable Dryland Ecosystems and Societies(CSDES)-University of Nairobi,Kenya。
文摘Introduction:Rangelands are important source of pasture for livestock in Kenya since time immemorial to pastoral households.However,seasonality on forage availability has been a big challenge in meeting animals’feed requirements.This demands harvest and storage of pastures for use during dry seasons.Hay making has been done to bridge this forage deficit periods.However,hay quality in the rangelands is affected by curing methods,phonological stage at harvest,and the storage duration.We therefore evaluated the effect of field curing and storage duration on the quality(Crude Protein(CP))of hay from six rangeland grasses in Kenya.Methods:The grasses evaluated are Chloris roxburghiana,Eragrostis superba,Enteropogon macrostachyus,Cenchrus ciliaris,Chloris gayana,and Sorghum sudanense.These grasses are the common species in the rangelands of Kenya and have been promoted in the past for hay making and reseeding interventions.The grasses were harvested at the mature flowering stage(12 weeks phenological stage),which is a period that provides high biomass without much effect on quality as practiced in the study area.The grasses were then cured in the field for 1,2,and 3 days before baling and stored indoors for 12,24,and 36 weeks.Samples were taken for CP content determination at the three periods following Macro-Kjeldahl Method.Results:There was significant decline(p≤0.05)in crude protein content in all the grass species with storage periods.Curing period did not affect the CP content for all the species at a given storage period;however,3 days curing changed the hay color from green to brownish which reduces palatability and consequently reduced feed intake.Storage period of over 12 weeks adversely lowered CP to less than 6% for all the species which is the required minimum level for animal under production and maintenance.S.Sudanense had significantly higher decline in CP after 24 weeks storage compared to the other species.Conclusions:Therefore,hay from the six grass species harvested at mature flowering stage(12-week phonological stage)and stored longer than 12 weeks supplies the animals with low CP.Also,to maintain palatability,1-2 days curing is recommended for the six grass species.