RESUMO O estudo objetivou avaliar a distribuição espacial das defesas e das taxas de herbivoria em 20 espécies vegetais e a relação destas com o gradiente edáfico em quatro formações de restinga no Parque Estadual do Acaraí (PEA), Estado de Santa Catarina, Brasil. Atributos morfoanatômicos, histoquímicos e nutricionais foliares foram medidos em vinte folhas de dez indivíduos de cada espécie. Seis amostras de solo foram coletadas em cada formação para análise dos teores de macronutrientes, matéria orgânica, umidade e espessura da serapilheira. As análises estatísticas foram realizadas utilizando software R. Os resultados indicaram que as taxas de herbivoria variam de acordo com os atributos morfoanatômicos e histoquímicos foliares, os quais respondem às características nutricionais e hídricas do solo, influenciando o agrupamento de defesas anti-herbivoria em cada comunidade vegetal.

ABSTRACT This study aimed to evaluate the spatial distribution of defenses and herbivory rates in 20 plant species and their relationship with the edaphic gradient in four sandbank formations in the State Park of Acaraí (PEA) in Santa Catarina State, Brazil. The morphoanatomical, histochemical and nutritional attributes of the leaves were measured on twenty leaves of ten individuals of each species. Six soil samples were collected in each formation for analysis of macronutrient contents, organic matter, moisture and litter thickness. Statistical analyzes were performed with the R software. The results indicated that herbivory rates vary according to leaf morphoanatomical and histochemical attributes, which respond to the soil’s nutritional and water characteristics and, therefore, influence the anti-herbivory groups in each plant community.

Resumo A hipótese do vigor da planta sugere que plantas mais vigorosas suportam maior densidade de galhas. Este estudo avaliou tal hipótese utilizando o sistema ácaro-Baccharis longiattenuata em duas populações de restinga sob condições ambientais distintas. As medidas de vigor incluíram: altura e diâmetro do caule, volume e área da copa, número de folhas por ramo, teor de nitrogênio e área específica foliar. Os resultados evidenciaram o efeito do vigor sobre a densidade de galhas. Além do vigor da planta, outros fatores podem ter influenciado indiretamente no padrão observado. O maior aporte hídrico em restinga arbustivo-arbórea pode influenciar nas taxas de crescimento e formação de sítios meristemáticos, alterando a dinâmica galhador-hospedeiro. Diferente do esperado pela literatura, a população com folhas menos esclerófilas apresentou maior densidade de galhas. Por outro lado, em restinga arbustiva, os menores valores de AEF, em resposta à alta incidência luminosa e menor disponibilidade hídrica no solo, podem ter influenciado a maior densidade de ácaros por galha. Folhas mais esclerófilas e longevas favorecem o tempo de permanência de fêmeas na galha, aumentando a densidade de ácaros por galha neste ambiente. É apresentada uma discussão sobre as condições ambientais que podem moldar o padrão de distribuição das galhas encontrado.

Abstract The plant vigor hypothesis suggests that more vigorous plants support higher density of galls. This study will evaluate such hypothesis using a mite-Baccharis longiattenuata system in two restinga populations under different environmental conditions. The measures of vigor are: height and stem diameter, volume and crown area, number of leaves per branch, nitrogen content and specific leaf area. The results evidenced the vigor effect on the density of galls. In addition to plant vigor, other factors may have indirectly influenced the observed pattern. In shrub-tree restinga, the highest water intake may have influenced the growth rates and formation of meristematic sites, which changes the gall-host dynamics. Different than expected in the literature, a population with less sclerophyllous leaves presented higher density of galls. On the other hand, in shrub restinga, the lowest SLA values, in response to high light incidence and lower soil water availability, may be influenced by higher density of mites per gall, since more sclerophyllous leaves have greater longevity, favoring in the time of permanence of the mature female inside the gall, increasing the density of mites per gall in this environment. A discussion is presented of environmental conditions that conform to the gall distribution pattern found.

RESUMO Analisou-se a plasticidade morfoanatômica foliar de Smilax campestris (Smilacaceae) em distintas formações de restinga, em gradiente ambiental na planície costeira de São Francisco do Sul, SC, Brasil. De cada um dos vinte indivíduos selecionados por formação, foram coletadas folhas completamente expandidas, totalizando 140 folhas por ambiente destinadas à caracterização morfoanatômica. A heterogeneidade ambiental foi caracterizada pela nutrição do solo e radiação luminosa. Os dados foram avaliados por meio de ANOVA e PCA. Todos os atributos foliares analisados, bem como as variáveis ambientais, apresentaram diferença estatisticamente significativa entre as formações de restinga, com destaque aos atributos de massas seca e fresca, área foliar, área específica foliar, espessura da epiderme abaxial e densidade foliar. As variáveis ambientais de maior destaque foram: matéria orgânica, saturação por base, soma de bases e teor de magnésio. Os ajustes morfoanatômicos de S. campestris em resposta às distintas condições ambientais resultaram no uso de folhas esclerófilas e com características xeromórficas mais acentuadas próximo ao mar que se tornam gradativamente menores rumo ao continente.

ABSTRACT In this study, the foliar morphoanatomical plasticity of Smilax campestris (Smilacaceae) was analyzed along an environmental gradient in different restinga formations, in the coastal plain of São Francisco do Sul, Santa Catarina State, Brazil. Twenty individuals were selected by formation, from which 140 leaves were collected for the morphoanatomical characterization. The environmental heterogeneity was characterized by soil nutrition and light radiation. Data were evaluated using ANOVA and PCA. All the leaf traits analyzed, as well as the environmental variables, showed a statistically significant difference among the four restinga formations, with emphasis on the traits of dry mass, fresh mass, leaf area, specific leaf area, abaxial epidermis thickness and leaf density. The main environmental variables were: organic matter, base saturation, sum of bases and magnesium content. The morphoanatomical adjustments of S. campestris in response to different environmental conditions resulted in sclerophyllous leaves, with a pronounced xeromorphic appearance near the sea that gradually becomes less evident within the continent.

ABSTRACT Plant-herbivore interactions have directed the evolution of defense mechanisms in plants, which can vary intraspecifically according to environmental quality. This study evaluated variation in the production of antiherbivory defenses in plant species distributed along an environmental gradient of restinga. The study was performed in Parque Estadual Acaraí, state of Santa Catarina, Brazil. Three species of four plant formations with different abiotic conditions were selected for study. Specific leaf area; water, nitrogen and carbon content; and presence of phenols, tannins, lignin and alkaloids, were evaluated in leaves of ten plants per species per plant formation. The results indicated that Symphyopappus casarettoi possesses Low Nutritional Quality Syndrome, characterized by low specific leaf area, presence of secondary metabolites and low nitrogen content. Dodonaea viscosa and Varronia curassavica possess Nutrition and Defense Syndrome, characterized by a balance between nutritional quality (high nitrogen content and lower C:N ratio) and protection (greater thickness of leaves and higher density of trichomes). The results did not confirm the Resource Availability Hypothesis. The absence of a pattern in antiherbivory response due to the environmental gradient may indicate that the investment in defense by plants is not unidirectional and that certain morpho-anatomical attributes are typically related to conservation of resources.

RESUMO As espécies do subosque são adaptadas à condição de sombreamento imposta pelo dossel. O presente estudo caracterizou, por meio de atributos foliares, as estratégias utilizadas por diferentes espécies de subosque. O estudo foi realizado no Jardim Botânico da Universidade da Região de Joinville, SC, Brasil. Foram selecionadas sete espécies ciófitas. De cada espécie foram selecionados cinco indivíduos, dos quais 25 folhas foram coletadas para análise morfoanatômica e de teor de clorofila. A intensidade luminosa incidente sobre cada espécime foi medida. Os resultados confirmaram o alto grau de sombreamento das plantas em subosque. A razão clorofila a/b foi >1 e, portanto, contrária a esperada. Os testes estatísticos evidenciaram a existência de padrões de resposta ao sombreamento, caracterizados morfologicamente pela massa fresca, área foliar, comprimento e largura do limbo e área específica foliar e, anatomicamente, pela espessura do parênquima lacunoso. A convergência destes atributos está relacionada ao maior aproveitamento da luz que atinge o subosques.

ABSTRACT Understory species are adapted to shade condition imposed by the canopy. This study characterized, by means of leaf attributes, the strategies used by different species of understory. The study was conducted at the Botanical Garden of the University of the Region of Joinville, Santa Catarina State, Brazil. Seven shade species were selected. Of each species, five individuals were selected and 25 leaves were collected for morphological and anatomical analysis and chlorophyll content. The incident light intensity on each specimen was measured. The results confirmed the high degree of shading in understory plants. The ratio chlorophyll a/b was >1 and therefore contrary to expected. Statistical tests showed the existence of patterns of response to shading, morphologically characterized by fresh weight, leaf area, length and width of the blade and leaf specific area and, anatomically, the thickness of the spongy parenchyma. The convergence of these attributes is associated with greater use of light that reaches the understory.

ABSTRACT In ombrophilous forests, light stratification provokes different adjustments by plants for better use of the environmental conditions of each stratum. Among the morphological traits that vary with strata, the presence of bundle sheath extensions (BSEs) is related to water transport, photosynthesis, and leaf mechanical support and classifies leaves as homobaric or heterobaric. This study analyzed the proportion of these types of leaves in a Lowland Ombrophilous Dense Forest (LLODF) and a Mixed Ombrophilous Forest (MOF), and among the strata of each forest type. The morphological leaf traits of 89 LLODF tree species and 57 MOF tree species were examined. The proportion of homobaric and heterobaric leaves did not differ between forests. However, in both forest types, the distribution of species with heterobaric or homobaric leaves depended on strata, with heterobaric species occurring mainly in higher strata, and homobaric species in lower strata. Thus, light stratification acts as an ecological filter on the composition of the vegetation of these forests, favoring heterobaric species in places with higher light intensity and temperature, such as the highest strata of canopy. On the other hand, homobaric species are more frequent in lower strata, where light is less available and humidity higher.