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Aim of the study: Alien and indigenous species emergence patterns within canopy gaps in urban subtropical forests are poorly understood. This study compared canopy gap floristics in relation to abiotic and physical characteristics across three subtropical urban forests differing in disturbance history. Area of study: Three Northern Coastal Forests of varying disturbance histories located in coastal subtropical urban KwaZulu-Natal (KZN), South Africa (SA). Materials and methods: Closed canopy (n = 15 quadrats per forest ) and four gaps (n = 12 quadrats per forest) from three size classes (‘small’ < 25 m2, ‘medium’ 25 - 45 m2; ‘large’ > 45 m2) were surveyed for the primary least disturbed (PLD), primary highly disturbed (PHD) and transitional highly disturbed (THD) forests using classical vegetation sampling techniques. Soil moisture content and air temperature were measured within each gap. Main results: Cumulatively all forest gaps hosted 198 species. Equivalent number of species (Hill numbers from H = 0 to H = 2) were constantly higher in the PHD forest followed by the PLD forest and lowest in the THD forest. Alien and indigenous plant density were negatively correlated. Species richness was positively correlated with gap size and soil moisture content, and negatively correlated with air temperature. Research highlights: Gap floristic patterns are influenced by size, abiotic factors, disturbance and forest successional status. Floristic, abiotic and physical characteristics of gaps should be monitored within urban forests as these can influence gap infilling in terms of rate, species composition, and alien-indigenous plant interactions across the forest. This can inform management interventions such as species reintroduction and alien clearing.

Aim of the study: Alien and indigenous species emergence patterns within canopy gaps in urban subtropical forests are poorly understood. This study compared canopy gap floristics in relation to abiotic and physical characteristics across three subtropical urban forests differing in disturbance history. Area of study: Three Northern Coastal Forests of varying disturbance histories located in coastal subtropical urban KwaZulu-Natal (KZN), South Africa (SA). Materials and methods: Closed canopy (n = 15 quadrats per forest ) and four gaps (n = 12 quadrats per forest) from three size classes (‘small’ < 25 m2, ‘medium’ 25 - 45 m2; ‘large’ > 45 m2) were surveyed for the primary least disturbed (PLD), primary highly disturbed (PHD) and transitional highly disturbed (THD) forests using classical vegetation sampling techniques. Soil moisture content and air temperature were measured within each gap. Main results: Cumulatively all forest gaps hosted 198 species. Equivalent number of species (Hill numbers from H = 0 to H = 2) were constantly higher in the PHD forest followed by the PLD forest and lowest in the THD forest. Alien and indigenous plant density were negatively correlated. Species richness was positively correlated with gap size and soil moisture content, and negatively correlated with air temperature. Research highlights: Gap floristic patterns are influenced by size, abiotic factors, disturbance and forest successional status. Floristic, abiotic and physical characteristics of gaps should be monitored within urban forests as these can influence gap infilling in terms of rate, species composition, and alien-indigenous plant interactions across the forest. This can inform management interventions such as species reintroduction and alien clearing.

Pepper (Capsicum annuum L.) is one of the most consumed horticultural products worldwide. However, pepper seeds have slow and asynchronous germination. Organic agriculture encourages using natural substances for the pre-germinative treatment of seeds. The objective of the present work was to evaluate the effect of priming sweet pepper seeds with bromelain crude extract (obtained from pineapple stem residues) on subsequent seedling emergence and growth. The effects of the proteolytic activity of the extract (0, 3.16, 6.25, 12.25, and 25.0 totalU), imbibition time (0, 3, 6, 9, 12, and 15 h), and imbibition temperature (15, 25, 35 and 45 ℃) on seedling emergence and growth were assessed. The significantly best emergence, based on a range of indicators (emergence percentage: E, time to 50% emergence: TE50, emergence index: EI, mean emergence rate: MER, mean emergence time: MET, and synchronization index: SI), was obtained when the seeds were treated for three h at 35°C with a 6.25 totalU bromelain crude extract. Seeds subjected to this treatment combination also yielded the most vigorous seedlings (number of true leaves, length and thickness of the stems, fresh mass, dry mass, leaf area) . In conclusion, pre-germinative treatment with bromelain crude extract of 6.25 totalU proteolytic activity for three h at 35°C improved seedling emergence and growth in sweet pepper seedlings relative to untreated seed. This result offers an organic priming alternative for seeds of sweet pepper., El pimiento ( Capsicum annuum L.) es uno de los productos hortofrutícolas más consumidos a nivel mundial. Sin embargo, las semillas de pimiento tienen una germinación lenta y asincrónica. La agricultura orgánica fomenta el uso de sustancias naturales para el tratamiento pregerminativo de las semillas. El objetivo del presente trabajo fue evaluar el efecto del cebado de semillas de chile dulce con extracto crudo de bromelina (obtenido a partir de residuos de tallo de piña) sobre la posterior emergencia y crecimiento de las plántulas. Los efectos de la actividad proteolítica del extracto (0, 3.16, 6.25, 12.25 y 25.0 totalU), se evaluaron el tiempo de imbibición (0, 3, 6, 9, 12 y 15 h) y la temperatura de imbibición (15, 25, 35 y 45 ℃) sobre la emergencia y el crecimiento de las plántulas. La emergencia significativamente mejor, basada en una variedad de indicadores (porcentaje de emergencia: E, tiempo hasta la emergencia del 50 %: TE 50 , índice de emergencia: EI, tasa de emergencia media: MER, tiempo de emergencia medio: MET e índice de sincronización: SI), se obtuvo cuando las semillas se trataron durante tres horas a 35 °C con un extracto crudo de bromelina de 6,25 U totales . Las semillas sometidas a esta combinación de tratamientos también produjeron las plántulas más vigorosas (número de hojas verdaderas, longitud y grosor de los tallos, masa fresca, masa seca, área foliar). En conclusión, el tratamiento pregerminativo con extracto crudo de bromelina de 6.25 totalesLa actividad proteolítica U durante tres horas a 35 °C mejoró la emergencia y el crecimiento de las plántulas en las plántulas de pimiento dulce en relación con las semillas no tratadas. Este resultado ofrece una alternativa de cebado orgánico para semillas de pimiento dulce.

Herbivory is ubiquitous. Despite being a potential driver of plant distribution and performance, herbivory remains largely undocumented. Some early attempts have been made to review, globally, how much leaf area is removed through insect feeding. Kozlov et al., in one of the most comprehensive reviews regarding global patterns of herbivory, have compiled published studies regarding foliar removal and sampled data on global herbivory levels using a standardized protocol. However, in the review by Kozlov et al., only 15 sampling sites, comprising 33 plant species, were evaluated in tropical areas around the globe. In Brazil, which ranks first in terms of plant biodiversity, with a total of 46,097 species, almost half (43%) being endemic, a single data point was sampled, covering only two plant species. In an attempt to increase knowledge regarding herbivory in tropical plant species and to provide the raw data needed to test general hypotheses related to plant–herbivore interactions across large spatial scales, we proposed a joint, collaborative network to evaluate tropical herbivory. This network allowed us to update and expand the data on insect herbivory in tropical and temperate plant species. Our data set, collected with a standardized protocol, covers 45 sampling sites from nine countries and includes leaf herbivory measurements of 57,239 leaves from 209 species of vascular plants belonging to 65 families from tropical and temperate regions. They expand previous data sets by including a total of 32 sampling sites from tropical areas around the globe, comprising 152 species, 146 of them being sampled in Brazil. For temperate areas, it includes 13 sampling sites, comprising 59 species. Thus, when compared to the most recent comprehensive review of insect herbivory (Kozlov et al.), our data set has increased the base of available data for the tropical plants more than 460% (from 33 to 152 species) and the Brazilian sampling was increased 7,300% (from 2 to 146 speci

[EN] Knowing the mechanisms that operate under water stress in commercial crops, particularly those that can affect productivity, such as phenolic or cell wall metabolism, is becoming increasingly important in a scenario of global climate change. However, our understanding of how to analyse statistically the relationships between these commonly used biochemical markers of water stress and growth in crops like pineapple, needs to be improved. In the present work, we have addressed the question of whether polynomial regression analysis can be used to describe the influence of selected plant metabolites (chlorophylls, carotenoids, phenolics and aldehydes) on shoot biomass, in response to a mannitol-induced water stress in temporary immersion bioreactors (TIBs). Polynomial regression analysis has been applied to investigate plant stress responses in many species but is very seldom used in in vitro screening studies. Here, the relationship between biochemical indicators (x; independent variable) and shoot growth (y; dependent variable) has been characterised, with y modelled as an nth degree polynomial in x. This statistical approach accommodated for the non-linear (curvilinear) relationships between variables, and the results showed that shoot biomass was negatively, and significantly correlated with soluble phenolics, cell wall-linked phenolics and other aldehydes (characterised by ¿High¿ R2 values).

The restoration of degraded forests to enhance biodiversity, ecosystem services, as well as climate change mitigation and adaptation is now a major priority in cities around the world. This study evaluated the success of the Buffelsdraai Landfill Site Community Reforestation Project in Durban, South Africa, by assessing ecological attributes. Measures of plant richness, diversity, vegetation structure, invasive alien plants (IAPs) and ecological processes were contrasted across a chronosequence of habitats under restoration (0-year-old, 3-year-old and 5-year-old) and compared with a reference forest habitat (remnant natural forest). Native tree species recruitment and vegetation structure increased with restoration age. Ecological processes, represented by the composition of pollination and seed dispersal traits in all of the habitats under restoration, were similar to the reference habitat. However, low tree density and an increase in IAP cover with an increase in restoration age were identified as threats to reforestation success. We recommend enrichment planting and an effective IAP management strategy to promote more rapid habitat restoration while reducing site maintenance costs. Enrichment planting should not only focus on increasing tree species density and richness, but also on the inclusion of species with missing pollination and seed dispersal categories.

The restoration of degraded forests to enhance biodiversity, ecosystem services, as well as climate change mitigation and adaptation is now a major priority in cities around the world. This study evaluated the success of the Buffelsdraai Landfill Site Community Reforestation Project in Durban, South Africa, by assessing ecological attributes. Measures of plant richness, diversity, vegetation structure, invasive alien plants (IAPs) and ecological processes were contrasted across a chronosequence of habitats under restoration (0-year-old, 3-year-old and 5-year-old) and compared with a reference forest habitat (remnant natural forest). Native tree species recruitment and vegetation structure increased with restoration age. Ecological processes, represented by the composition of pollination and seed dispersal traits in all of the habitats under restoration, were similar to the reference habitat. However, low tree density and an increase in IAP cover with an increase in restoration age were identified as threats to reforestation success. We recommend enrichment planting and an effective IAP management strategy to promote more rapid habitat restoration while reducing site maintenance costs. Enrichment planting should not only focus on increasing tree species density and richness, but also on the inclusion of species with missing pollination and seed dispersal categories.

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