Structure of a Semideciduous Seasonal Forest in the National Forest of Ipanema,Brazil:Contributing to the Floristic Knowledge of a Poorly Studied Protected Area

Studies on composition and structure generate crucial information for characterizing plant communities and planning conservation actions.There are still substantial knowledge gaps in Brazilian protected areas,preventing design programs to mitigate biodiversity loss.This is the case of the National Forest of Ipanema(Ipanema NAFO)in São Paulo state,Brazil,where plant diversity remains uncalculated.To help fill this gap,in 1-ha of a seasonal semideciduous forest(SSF)stand on the Araçoiaba hill,the authors sampled all woody stems with dbh≥5 cm in a total of 103 dead and 1,301 living plants representing 65 species,57 genera,and 31 families.The number of species and families was lower than old-growth SSF and,together with the land-use history,which suggests the community is a secondary stand.The initial species Guazuma ulmifolia,Machaerium stipitatum,Croton floribundus,and Aloysia virgata totalized 50%of the living stems,whereas 37%of the other species summed up only 1.8%.The high abundance of these initial species and the presence of the climax species Cariniana legalis,Holocayx balansae,Myroxylon peruiferum,Zanthoxylum caribaeum and others indicate that the community is in an intermediate to advanced successional stage.Three species are considered vulnerable to extinction and 27 of least concern.Ipanema NAFO is an important conservation unit,sheltering some plants vulnerable to extinction and others locally rare.This study adds to other few studies about the flora of Ipanema NAFO,helping to estimate its biodiversity and planning conservation actions.Additionally,it is a source for defining reference values for ecological restoration in the Atlantic forest.

Plant Diversity and Carbon Stock Assessment in an Informal Settlement of the City of Yaounde, Cameroon: The Case of Elig-Effa West

Due to rapid demographic growth, economic and technological changes, urban environments are highly exposed to the impacts of climate change and environmental catastrophes. Despite the pressure to which urban forests are exposed, they still play important roles through the service they provide: air quality, shade, and reduction of dioxide of carbon. The present study was carried out in the city of Yaoundé, Cameroon, especially in one of its suburb areas, Elig-Effa West, a neighborhood with spontaneous settlements. The study aimed at assessing the plant species diversity, and carbon sequestration potentials of diverse trees recorded using indirect methods. Six sampling plots of 100 × 100 m were established in the study area. Our results recorded a total of 16 species grouped into 12 families. Apocynaceae, Mimosaceae and Moraceae were the most represented families. The most represented species throughout the sampling plots were Mangifera indica, Persea americana, Annona muricata and Psidium gaujava, which are all fruiting trees. Carbon stock for the study area was estimated at 16.08 ± 5.60 tC with an average of 0.23 ± 0.08 tC/ha. The results also showed the species to be considered in a potential restoration program should be first fruiting trees, followed by non-fruiting trees useful to population, especially those that have their trunk peeled, a sign that they are used by the population. Nevertheless, informal settlements contribute to carbon sequestration, that well targeted urban reforestation will substantially improve.

Agroecological Influence on Rice Field Weeds in Anosibe Ifanja Commune(Middle West Madagascar)

Weeds, which cause loss of more than half of production, constitute one of obstacles to development of agriculturalproduction in Madagascar. This study aimed to characterize weed flora and to analyze constraint of weeding irrigated rice with aview to improve control strategy. A phytoecological study of weeds was carried out during 2018-2019 season, on 125 rice plots withan average area of 500 m², in Anosibe Ifanja, Middle-West region of Madagascar (18°52′ S and 46°50′ E). Surveys on croppingpractices and observations on rice field ecology and the importance of weed cover level were carried out in order to establishrelationship between factors affecting diversity, distribution and level of weed infestation in rice field. As a result, 47 weed speciesgrouped into about 20 families were identified. Weed cover quantification in each plot, permits to distinguish three major importancespecies, including Junglerice - Echinochloa colona (Poaceae), Tail - Leersia hexandra (Oryzoideae), saramollagrass - Ischaemumrugosum (Poaceae) and hemp sesbania - Sesbania rostrata (Fabaceae). Analysis of agro-ecological factors showed that all productiontechniques and growing conditions have a role to play in variability of plant cover level. Thus, the main production factors thatvegetation cover reduce state are ploughing to a depth of 30 cm, practice of ploughing off-season/in-season and good water control.Ecological factors, especially soil type, soil structure and topography, minimize weed cover in rice fields.