Consumo de frutos por Chrysocyon brachyurus (Illiger, 1815) (Carnivora, Canidae): efeitos de ser comido e suas implicações para conservação do cerrado
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Data
2022-01-20
Autores
Reis, Samia Cardoso dos
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Universidade Estadual Paulista (Unesp)
Resumo
A endozoocoria é um processo fundamental para muitas espécies vegetais, podendo ser o principal mecanismo de dispersão, permitindo as sementes alcançarem locais adequados a sua germinação e crescimento. No cerrado, o lobo-guará (Chrysocyon brachyurus) é reconhecido como uma importante espécie dispersora de sementes, tendo grande potencial para auxiliar na restauração ecológica de ambientes degradados, perpetuando e favorecendo a conservação de espécies vegetais. No entanto, o fato de consumirem frutos não implica necessariamente que as sementes sejam dispersas viáveis para germinação. Devido a passagem pelo trato digestório do animal, as sementes podem ser afetadas em relação à sua viabilidade. Neste contexto, este estudo teve como objetivo testar a hipótese de que a passagem de sementes de frutos que ocorrem no Cerrado pelo trato digestório de C. brachyurus melhora as taxas de germinação (aumento da porcentagem de sementes germinadas e diminuição do tempo médio de germinação), quando comparadas com sementes não ingeridas pelo animal. O presente trabalho foi desenvolvido com dois exemplares de C. brachyurus do plantel do Centro de Conservação de Fauna Silvestre de Ilha Solteira. As espécies vegetais selecionadas foram jenipapo (Genipa americana), goiaba (Psidium guajava), araçá (Psidium cattleianum), jabuticaba (Plinia cauliflora) e figo (Ficus sp.). Foram coletadas sementes diretamente das frutas, para compor as amostras Controle, e das fezes dos animais para as amostras Lobo-guará. Todas as sementes foram lavadas em água corrente e secas a temperatura ambiente e semeadas em quatro repetições por grupo/fruto com 50 sementes em cada repetição (total de 400 sementes por fruto), regadas diariamente. Foram adotadas como medidas de germinação a porcentagem e o índice de velocidade de emergência (IVE) e comparada entre os tratamentos por meio de Teste-t. Para as espécies G. americana e P. guajava, sementes do tratamento lobo-guará apresentaram taxa de germinação maiores e IVE menores significativamente em relação ao tratamento controle. Para P. cattleianum, observou-se maior taxa de germinação e IVE para o tratamento controle. Já para as sementes das espécies Ficus sp. e P. cauliflora, não foram observadas diferenças significativas para taxa de germinação das sementes e IVE entre os tratamentos. Em função dos resultados encontrados, fica evidente que C. brachyurus é um canídeo com alto potencial dispersor, pois houve germinação em todas as espécies vegetais utilizadas no presente estudo. Demonstrando assim que, há uma interação mutualística importante entre esse animal e essas espécies vegetais.
Endozoochory is a fundamental process for many plant species, and it can be the main dispersal mechanism, allowing seeds to reach suitable places for their germination and growth. In the Cerrado, the maned wolf (Chrysocyon brachyurus) is recognized as an important seed disperser species, with great potential to assist in the ecological restoration of degraded environments, perpetuating and favoring the conservation of plant species. However, the fact that they consume fruits does not necessarily imply that the seeds are dispersed viable for germination. Due to the passage through the animal's digestive tract, the seeds can be affected in relation to their viability. In this context, this study tested the hypothesis that the passage of seeds that occur in the Cerrado fruits through the digestive tract of C. brachyurus improves germination rates (increase in the percentage of germinated seeds and decrease in the mean germination time), when compared to seeds not ingested by the animal. This work was developed with two specimens of C. brachyurus from the Wild Fauna Conservation Center of Ilha Solteira. The selected plant species were jenipapo (Genipa americana), guava (Psidium guajava), araçá (Psidium cattleianum), jabuticaba (Plinia cauliflora) and fig (Ficus sp.). Seeds were collected directly from fruits, to compose the control samples, and from animal feces for the Maned Wolf samples. All seeds were washed in running water and dried at room temperature and sown in four replications per group/fruit with 50 seeds in each replication (400 seeds per fruit), watered daily. The germination percentage and the emergence speed index (IVE) were adopted as germination measures and compared between treatments using t-test. For species G. americana and P. guajava, seeds from the maned wolf treatment presented higher germination rate and significantly lower IVE than the control treatment. For P. cattleianum, a higher germination rate and IVE were observed for the control treatment. As for the seeds of the Ficus sp. and P. cauliflora, no significant differences were observed for seed germination rate and IVE between treatments. Based on the results found, it is evident that C. brachyurus is a canid with high dispersion potential, as there was germination in all plant species used in this study. Thus, demonstrating an important mutualistic interaction between this animal and these plant species.
Endozoochory is a fundamental process for many plant species, and it can be the main dispersal mechanism, allowing seeds to reach suitable places for their germination and growth. In the Cerrado, the maned wolf (Chrysocyon brachyurus) is recognized as an important seed disperser species, with great potential to assist in the ecological restoration of degraded environments, perpetuating and favoring the conservation of plant species. However, the fact that they consume fruits does not necessarily imply that the seeds are dispersed viable for germination. Due to the passage through the animal's digestive tract, the seeds can be affected in relation to their viability. In this context, this study tested the hypothesis that the passage of seeds that occur in the Cerrado fruits through the digestive tract of C. brachyurus improves germination rates (increase in the percentage of germinated seeds and decrease in the mean germination time), when compared to seeds not ingested by the animal. This work was developed with two specimens of C. brachyurus from the Wild Fauna Conservation Center of Ilha Solteira. The selected plant species were jenipapo (Genipa americana), guava (Psidium guajava), araçá (Psidium cattleianum), jabuticaba (Plinia cauliflora) and fig (Ficus sp.). Seeds were collected directly from fruits, to compose the control samples, and from animal feces for the Maned Wolf samples. All seeds were washed in running water and dried at room temperature and sown in four replications per group/fruit with 50 seeds in each replication (400 seeds per fruit), watered daily. The germination percentage and the emergence speed index (IVE) were adopted as germination measures and compared between treatments using t-test. For species G. americana and P. guajava, seeds from the maned wolf treatment presented higher germination rate and significantly lower IVE than the control treatment. For P. cattleianum, a higher germination rate and IVE were observed for the control treatment. As for the seeds of the Ficus sp. and P. cauliflora, no significant differences were observed for seed germination rate and IVE between treatments. Based on the results found, it is evident that C. brachyurus is a canid with high dispersion potential, as there was germination in all plant species used in this study. Thus, demonstrating an important mutualistic interaction between this animal and these plant species.
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Palavras-chave
Dispersão de sementes, Ecologia, Lobo-guará, Taxas de germinação, Zoocoria, Seed dispersion, Ecology, Maned wolf, Germination rates, Zoochory