Riparian Tree Vegetation Diversity Salah Nama Island in Banyuasin, South Sumatera

Highlight Research:Riparian plants play an important role in maintaining the balance of an aquatic ecosystem.The diversity of riparian aquatic plants on the island of Salah Nama BanyuasinData collection on riparian plants used the quadratic transect methodThe results showed that there were 21 types of riparian aquatic plants in 16 families.The highest composition is in the Lythraceae family, namely Sonneratia acidaAbstractRiparian plants play an important role in maintaining the balance of an aquatic ecosystem. The missing plant components from a water can cause sedimentation and change the microhabitat in these waters. The purpose of the study is to determine the diversity of riparian aquatic plants on the island of Salah Nama Banyuasin. The research was conducted in August 2016, November 2016, and January 2017 at Salah Nama Island Mariana Ilir Banyuasin 1, South Sumatra. Sampling was done by using the purposive sampling method. Determination of the sampling location used GPS (Global positioning system). Observation stations consisted of 5 sampling locations. The method of taking water plants was done in exploratory way. Data collection on riparian plants used the quadratic transect method measuring 1 m x 1 m. Samples of riparian plants were taken then wrapped with newspaper or paper and put into large plastic, labeled then taken to the testing laboratory Institute Inland fisheries and extension, Palembang. The results showed that there were 21 types of riparian aquatic plants in 16 families. The highest composition is in the Lythraceae family, namely Sonneratia acida. The diversity index of aquatic plants ranges from 1 <H'<3 in the stable condition category. Based on the results of the study, the riparian plant species that dominated the most were Sonneratia sp. The conclusion that can be drawn is that the diversity of riparian plants on the island of Salah Nama is in the medium category, the dominant riparian plants are Sonneratia sp.

Flood disturbance affects morphology and reproduction of woody riparian plants

Riparian forests are structured and maintained by their hydrology. Woody riparian plants typically adapt to the local flood regime to maximise their likelihood of survival and reproductive success. Understanding how extant trees form and reproduce in response to flood disturbance is crucial for predicting vegetation changes and informing restoration. Working in a temperate evergreen riparian forest, we aimed to determine whether disturbance-based responses of plants found in other ecosystems also typify woody plants in riparian forests where disturbances are often mild or chronic, non-lethal, annual events. Using plant surveys and 20-year modelled hydrological data, we examined whether (1) the morphology (main stem diameter, height, crown width, crown extent, stem leaning) and (2) reproduction type (sexual and asexual reproduction) and extent of three dominant woody species (Eucalyptus camphora, Leptospermum lanigerum and Melaleuca squarrosa) vary with flood regime (flood frequency and flood duration); and (3) whether different morphology is associated with different reproductive strategies. Increased flooding generally resulted in increased stem numbers and greater stem leaning—morphologies associated with asexual reproduction—of our study species. More frequent flooding also reduced plant size and sexual reproduction in E. camphora. Sexual reproduction in the studied species was more common in taller plants with single, more upright stems in good condition. Flexible morphology and plastic reproductive strategy may constitute an adaptation of trees to mild or chronic disturbance in floodplains. Our findings suggest that flood regime (i.e. variable frequency and duration of flooding events) is critical to the structural integrity and self-maintenance of species-diverse riparian forests.

Population genetic structure and connectivity of a riparian selfing herb Caulokaempferia coenobialis at a fine-scale geographic level in subtropical monsoon forest

Background Rivers and streams facilitate movement of individuals and their genes across the landscape and are generally recognized as dispersal corridors for riparian plants. Nevertheless, some authors have reported directly contrasting results, which may be attributed to a complex mixture of factors, such as the mating system and dispersal mechanisms of propagules (seed and pollen), that make it difficult to predict the genetic diversity and population structure of riparian species. Here, we investigated a riparian self-fertilizing herb Caulokaempferia coenobialis, which does not use anemochory or zoochory for seed dispersal; such studies could contribute to an improved understanding of the effect of rivers or streams on population genetic diversity and structure in riparian plants. Using polymorphic ISSR and cpDNA loci, we studied the effect at a microgeographic scale of different stream systems (a linear stream, a dendritic stream, and complex transverse hydrological system) in subtropical monsoon forest on the genetic structure and connectivity of C. coenobialis populations across Dinghu Mountain (DH) and Nankun Mountain (NK). Results The results indicate that the most recent haplotypes (DH: H7, H8; NK: h6, h7, h11, h12) are not shared among local populations of C. coenobialis within each stream system. Furthermore, downstream local populations do not accumulate genetic diversity, whether in the linear streamside local populations across DH (H: 0.091 vs 0.136) or the dendritic streamside local populations across NK (H: 0.079 vs 0.112, 0.110). Our results show that the connectivity of local C. coenobialis populations across DH and NK can be attributed to historical gene flows, resulting in a lack of spatial genetic structure, despite self-fertilization. Selfing C. coenobialis can maintain high genetic diversity (H = 0.251; I = 0.382) through genetic differentiation (GST = 0.5915; FST = 0.663), which is intensified by local adaptation and neutral mutation and/or genetic drift in local populations at a microgeographic scale. Conclusion We suggest that streams are not acting as corridors for dispersal of C. coenobialis, and conservation strategies for maintaining genetic diversity of selfing species should be focused on the protection of all habitat types, especially isolated fragments in ecosystem processes.

Influence of diversion power stations on riparian plant communities along Dicun stream China

This article used three diversion power stations with different operating years along Dicun stream of the source of Jiulong River to study the riparian plant community and discussed the impact of power station development on riparian plants. The results showed that:(1)There were significant differences in the plant diversity of herbs, shrubs and trees among all sample plots in the study area (P < 0.05).(2) The species number of the second and third diversion power stations with longer operation time was larger than that of the fourth diversion power station with short operation time.(3) The water-borne plants were concentrated in the herb layer in the influence area of the diversion power station, and the Richness, Shannon- Wiener, Simpson and Pielou indexes of water-borne plants in the study area were significantly different (P < 0.05). (4) The appearance of diversion power station leaded to the change of environmental factors, and the river depth and flow rate had significant positive correlation with the diversity index of riparian plants and water water-borne plants (P < 0.05). In general, with the increase of the operation time of the power station, the surrounding riparian plant will form a new stable community.

Bulk Drag Predictions of Riparian Arundo donax Stands through UAV-Acquired Multispectral Images

Estimating the main hydrodynamic features of real vegetated water bodies is crucial to assure a balance between their hydraulic conveyance and environmental quality. Riparian vegetation stands have a high impact on vegetated channels. The present work has the aim to integrate riparian vegetation’s reflectance indices and hydrodynamics of real vegetated water flows to assess the impact of riparian vegetation morphometry on bulk drag coefficients distribution along an abandoned vegetated drainage channel fully covered by 9–10 m high Arundo donax (commonly known as giant reed) stands, starting from flow average velocities measurements at 30 cross-sections identified along the channel. A map of riparian vegetation cover was obtained through digital processing of Unnamed Aerial Vehicle (UAV)-acquired multispectral images, which represent a fast way to observe riparian plants’ traits in hardly accessible areas such as vegetated water bodies in natural conditions. In this study, the portion of riparian plants effectively interacting with flow was expressed in terms of ground-based Leaf Area Index measurements (LAI), which easily related to UAV-based Normalized Difference Vegetation Index (NDVI). The comparative analysis between Arundo donax stands NDVI and LAI map enabled the analysis of the impact of UAV-acquired multispectral imagery on bulk drag predictions along the vegetated drainage channel.

Flood disturbance affects morphology and reproduction of woody riparian plants

Riparian forests are structured and maintained by their hydrology. Woody riparian plants typically adapt to the local flood regime to maximise their likelihood of survival and reproductive success. Understanding how extant trees form and reproduce in response to flood disturbance is crucial for predicting vegetation changes and informing restoration. Working in a temperate evergreen riparian forest, we aim to determine whether disturbance-based responses of plants found in other ecosystems also typify woody plants in riparian forests where disturbances are non-lethal, annual events. Using plant surveys and 20-year modelled hydrological data, we examined whether i) the morphology (main stem diameter, height, crown width, crown extent, stem leaning) and ii) reproduction type (sexual and asexual reproduction) and extent of three dominant woody species (Eucalyptus camphora, Leptospermum lanigerum and Melaleuca squarrosa) vary with flood regime (flood frequency and flood duration); and iii) whether different morphology is associated with different reproductive strategies. Increased flooding generally resulted in increased stem numbers and greater stem leaning – morphologies associated with asexual reproduction – of our study species. More frequent flooding also reduced plant size and sexual reproduction in E. camphora. Sexual reproduction in the studied species was more common in taller plants with single, more upright stems in good condition. Flexible morphology and plastic reproductive strategy may constitute an adaptation to mild or chronic disturbance in floodplains. Our findings suggest that woody plants respond to physical disturbance in consistent ways regardless of the nature of the disturbance – be it fires, hurricanes or floods.