Abstract
In tropical dry forests, the dynamics of herbaceous populations is strongly influenced by seasonal and annual variation in total rainfall. Moreover, the present and past events of climatic anomalies (e.g. severe drought years and erratic rain before the growth season) may cause drastic reductions in population size, leading to the temporal disappearance of some species. Therefore, this three-year study aimed to assess the dynamics of Delilia biflora (Asteraceae), Commelina obliqua (Commelinaceae), Phaseolus peduncularis (Fabaceae) and Euphorbia heterophylla (Euphorbiaceae). The study was conducted in an area of tropical dry forest known as Caatinga, situated in the experimental station of the Pernambuco Agronomic Institute (IPA), in Caruaru, Pernambuco, Brazil. The Caatinga has a semiarid climate with strong seasonal and annual variation in total precipitation. During this study, there was a climatic anomaly event called the 2006 drought, and also erratic rains in the dry season. The birth, death and survival of plants were evaluated monthly using 105 plots (1 × 1 m). Differences in density between years and seasons were evaluated using the Kruskal-Wallis test. The explanatory power of present and past precipitation on density was evaluated using the General Linear Model. In this study, we present the first record of Euphorbia heterophylla in the studied area. The studied populations were larger during the rainy seasons and in wet years, and were drastically reduced in the driest year and dry seasons. Commelina obliqua was the least sensitive to variation in total rainfall. Regarding the variation in density, all four species were present during all three years. Birth rates were higher during the rainy season, and death rates were higher in the dry season. Sporadic rain in the dry season caused pronounced seedling recruitment followed by death, and had a strong impact on the dynamics of D. biflora, E. heterophylla and P. peduncularis. The precipitation of the current year explained between 3 % - 18 % of the inter-annual density variation, and the explanatory power of the previous year precipitation on the density of populations ranged from 32 % to 67 %. Therefore, climatic events of the past also have a significant consequence over the four populations. In conclusion, drastic reduction in total precipitation between years may be considered as a predictive parameter for herbaceous plants population size (in the present and future time) in a Northeastern Brazilian tropical dry forest area.
References
Alcoforado-Filho, F. G., Sampaio, E. V. S. B., & Rodal, M. J. N. (2003). Florística e fitossociologia de um remanescente de vegetação caducifólia espinhosa arbórea em Caruaru. Acta Botanica Brasilica, 17, 287-303.
Almazán-Núñez, R. C., Arizmendi, M. D. C., & Eguiart, P. C. (2012). Changes in composition, diversity and structure of woody plants in successional stages of tropical dry forest in southwest Mexico. Revista Mexicana de Biodiversidad, 83, 1096-2010.
Andrade, J. R., Santos, J. M. F. F., Lima, E. M., Lopes, C. G. R., Silva, K. A., & Araújo, E. L. (2007). Estudo populacional de Panicum trichoides Swart. (Poaceae) em uma área de Caatinga em Caruaru, Pernambuco. Revista Brasileira de Biociências, 5, 858-860.
Araújo, E. L. (2005). Estresses abióticos e bióticos como forças modeladoras da dinâmica de populações vegetais da Caatinga. In R. J. M. C. Nogueira, E. L. Araújo, L. G. Willadino, & U. M. T. Cavalcante (Eds.), Estresses ambientais: danos e benefícios em plantas (pp. 50-64). Recife, Brazil: MXM Gráfica e Editora.
Araújo, E. L., Castro, C. C., & Albuquerque, U. P. (2007). Dynamics of Brazilian Caatinga - a review concerning the plants, environment and people. Functional Ecology and Communities, 1, 15-28.
Araújo, E. L., Silva, K. A., Ferraz, E. M. N., Sampaio, E. V. S. B., & Silva, S. I. (2005). Diversidade de herbáceas em microhabitats rochoso, plano e ciliar em uma área de Caatinga, Caruaru- PE. Acta Botanica Brasilica, 19, 285-294.
Ayres, M., Ayres-júnior, M., Ayres, D. L., & Santos, A. A. S. (2007). BioEstat – Aplicações estatísticas nas áreas das ciências bio-médicas. Belém: Ong Mamiraua.
Belsky, A. J. (1990). Tree/grass ratios in East African savannas: a comparison of existing models. Journal of Biogeography, 17, 483-489.
Castellani, T. T., Scherer, K. Z., & Paula, G. S. (2001). Population ecology of Paepalanthus polyanthus (Bong) Kunth: Demography and life history of a sand dune monocarpic plant. Revista Brasileira de Botânica, 24, 123-124.
Chesson, P., Gebauer, R. L. E., Schwinning, S., Huntly, N., Wiegand, K., Ernest, M. S. K., … Weltzin, J. F. (2004). Resource pulses, species interactions, and diversity maintenance in arid and semi-arid environments. Oecologia, 141, 236-253.
Condit, R., Hubbell, S., & Foster, R. B. (1996). Changes in tree species abundance in a neotropical forest: impact of climate change. Journal of Tropical Ecology, 12, 231-256.
Dahwa, E., Mudzengi, C. P., Hungwe, T., Shoko, M. D., Poshiwa, X., Kativu, S., & Murungweni, C. (2013). Influence of grazing intensity on soil properties and shaping herbaceous plant communities in semi-arid dambo wetlands of Zimbabwe. Journal of Environmental Protection, 4, 1181-1188.
García-Cháves, J. H., Montaña, C., Perroni, Y., Sosa, V. J., & García-Licona, J. B. (2014). The relative importance of solar radiation and soil origin in cactos seedling survivorship at two spatial scales: plant association and microhabitat. Journal of Vegetation Science, 25, 668-680.
Goldberg, B. E., & Turner, R. M. (1986). Vegetation change and plant demography in permanent plots in the sonoran desert. Ecology, 67(3), 695-712.
Gotelli, N. J. (2007). Ecologia. Londrina: Editora Planta.
Haskell, D. E., Flaspohler, D. J., Webster, C. R., & Meyer, M. W. (2010). Variation in soil temperature, moisture, and plant growth with the addition of downed woody material on lakeshore restoration sites. Restoration Ecology, 20(1), 113-121.
Khurana, E., & Singh, J. S. (2001). Ecology of seed and seedling growth for conservation and restoration of tropical dry forest: a review. Environmental Conservation, 28, 39-52.
Lima, E. M., Araújo, E. L., Ferraz, E. M. N., Sampaio, E. V. S. B., Silva, K. A., & Pimentel, R. M. M. (2007). Fenologia e dinâmica de duas populações herbáceas da Caatinga. Revista de Geografia, 24, 124-141.
Lucena, R. F. P., Nascimento, V. T., Araújo, E. L., & Albuquerque, U. P. (2008). Local uses of native plants in an area of Caatinga vegetation (Pernambuco, NE-Brazil). Ethnobotany Research and Applications, 6, 1-3.
Maron, J. L., & Crone, E. (2006). Herbivory: effects on plant abundance, distribution and population growth. Proceedings of the Royal Society, 273, 2575-2584.
Miller, A., & Duncan, R. (2003). Extrinsic and intrinsic controls on the distribution of the critically endangered cress, Ischnocarpus exilis (Brassicaceae). Biological Conservation, 110, 153-60.
Miriti, M. N., Rodríguez-Buritica, S., Wright, S. J., & Howe, H. (2007). Episodic death across species of desert shrubs. Ecology, 88(1), 32-36.
Mondragón, D., Durán, R., Ramírez, I., & Valverde, T. (2004). Temporal variation in the demography of the clonal epiphyte Tillandsia brachycaulos (Bromeliaceae) in the Yucatán Peninsula, Mexico. Journal of Tropical Ecology, 20, 189-200.
Monteiro, J. M., Lins Neto, E. M. N., Araújo, E. L., Amorim, E. L. C., & Albuquerque, U. P. (2011). Bark regeneration and tannin content in Myracrodruon urundeuva Allemão after simulation of extractive damages-implications to management. Environmental Monitoring and Assessment, 180, 31-39.
Mori, A. S., Silva, L. A. M., & Lisboa, G. (1989). Manual de manejo do herbário fanerogâmico. Ilhéus: Centro de Pesquisa do Cacau.
Nippert, J. B., Knapp, A. K., & Briggs, J. M. (2006). Intra-annual rainfall variability and grassland productivity: can the past predict the future? Plant Ecology, 184, 65-74.
Noel, F., Porcher, E., Moret, J., & Machon, N. (2005). Connectivity, habitat heterogeneity, and population persistence in Ranunculus nodiflorus, an endangered species in France. New Phytologist, 169, 71-84.
Nordbakken, J. F., Rydgren. K., & Okland, R. H. (2004). Demography and population dynamics of Drosera angelica and D. rotundifolia. Journal of Ecology, 92, 110-121.
Prado, D. (2003). As Caatingas da América do Sul. In I. R. Leal, M. Tabarelli, & J. M. C. Silva (Eds.), Ecologia e conservação da Caatinga (pp. 3-73). Recife, Brazil: Editora Universitária.
Reis, A. M., Araújo, E. L., Ferraz, E. M. N., & Moura, A. N. (2006). Inter-annual variations in the floristic and population structure of an herbaceous community of “Caatinga” vegetation in Pernambuco, Brazil. Revista Brasileira de Botânica, 29, 497-508.
Salo, L. F. (2004). Population dynamics of red brome (Bromus madritensis subsp. rubens): times for concern, opportunities for management. Journal of Arid Environments, 57, 291-296.
Sampaio, E. V. S. B. (1995). Overview of the Brazilian Caatinga. In S. Bullock, H. A. Mooney, & E. Medina (Eds.), Seasonally dry tropical forests (pp. 35-63). Cambridge: United Kingdom: Cambridge University Press.
Santos, D. M., Silva, K. A., Albuquerque, U. P., Santos, J. M. F. F., Lopes, C. G. R., & Araújo, E. L. (2013a). Can spatial variation and inter-annual variation in precipitation explain the seed density and species richness of the germinable soil seed bank in a tropical dry forest in Northeastern Brazil? Flora (Jena), 208, 445-452.
Santos, J. M. F. F., Andrade, J. R., Lima, E. M., Silva, K. A., & Araújo, E. L. (2007). Dinâmica populacional de uma espécie herbácea em uma área de floresta tropical seca na Nordeste do Brasil. Revista Brasileira de Biociências, 5, 855-857.
Santos, J. M. F. F., Santos, D. M., Lopes, C. G. R., Silva, K. A., Sampaio, E. V. S. B., & Araújo, E. L. (2013b). Natural regeneration of the herbaceous community in a semiarid region in Northeastern Brazil. Environmental Monitoring and Assessment, 185, 8287-8302.
Silva, K. A., Lima, E. M., Santos, J. M. F. F., Andrade, J. R., Santos, D. M., Sampaio, E. V. S. B., & Araújo, E. L. (2008). Dinâmica de gramíneas em uma área de Caatinga de Pernambuco-Brasil. In A. N. Moura, E. L. Araújo, & U. P. Albuquerque (Eds.), Biodiversidade, potencial econômico e processos eco-fisiológicos em ecossistemas nordestinos (pp. 39-64). Recife, Brazil: Comunigraf.
Suzuki, Z. O., Kudoh, H., & Kachi, N. (2003). Spatial and temporal variations in mortality of the biennial plant, Lysimachia rubida: effects of intraspecific competition and environmental heterogeneity. Journal of Ecology, 91, 114-125.
Swaine, M. D., & Lieberman, D. (1987). Note on the calculation of mortality rates. Journal of Tropical Ecology, 3, 2-3.
Thomson, D. (2005). Measuring the effects of invasive species on the demography of a rare endemic plant. Biological Invasions, 7, 615-624.
Vega, E., & Montaña, C. (2004). Spatio-temporal variation in the demography of a bunch grass in a patchy semiarid environment. Plant Ecology, 175, 107-120.
Vieira, D. L. M., & Scariot, A. (2006). Principles of natural regeneration of tropical dry forests for regeneration. Restoration Ecology, 14, 11-20.
Vilà, M., Bartolomeus, I., Gimeno, I., Traveset, A., & Moragues, E. (2006). Demography of the invasive geophyte Oxalis pes-caprae across a Mediterranean Island. Annals of Botany, 97, 1055-1062.
Villalobos, S. M., Poorter, L., & Martínez-Ramos, M. (2013). Effects of ENSO and Temporal Rainfall Variation on the Dynamics of Successional Communities in Old-Field Succession of a Tropical Dry Forest. Plos One, 8(12), 1-12.
Volis, S., Mendlinger, S., & Ward, D. (2004). Demography and role of the seed bank in Mediterranean and desert populations of wild barley. Basic and Applied Ecology, 5, 53-64.
Wang, R. Z. (2005). Demographic variation and biomass allocation of Agropyron cristatum grown on steppe and dune sites in the Hunshandake Desert, North China. Grass and Forage Science, 60, 99-102.
Zar, J. H. (1996). Biostatistical analysis. New Jersey: Prentice Hall.
Zotz, G. (1998). Demography of the epiphytic orchid, Dimerandra emarginata. Journal of Tropical Ecology, 14, 725-741.
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