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In degraded landscapes, recolonization by pioneer vegetation is often halted by the presence of persistent environmental stress. When natural expansion does occur, it is commonly due to the momentary alleviation of a key environmental variable previously limiting new growth. Thus, studying the circumstances in which expansion occurs can inspire new restoration techniques, wherein vegetation establishment is provoked by emulating natural events through artificial means. Using the salt‐marsh pioneer zone on tidal flats as a biogeomorphic model system, we explore how locally raised sediment bed forms, which are the result of natural (bio)geomorphic processes, enhance seedling establishment in an observational study. We then conduct a manipulative experiment designed to emulate these facilitative conditions in order to enable establishment on an uncolonized tidal flat. Here, we attempt to generate raised growth‐promoting sediment bed forms using porous artificial structures. Flume experiments demonstrate how these structures produce a sheltered hydrodynamic environment in which suspended sediment and seeds preferentially settle. The application of these structures in the field led to the formation of stable, raised sediment platforms and the spontaneous recruitment of salt‐marsh pioneers in the following growing season. These recruits were composed primarily of the annual pioneering Salicornia genus, with densities of up to 140 individuals/m2 within the structures, a 60‐fold increase over ambient densities. Lower abundances of five other perennial species were found within structures that did not appear elsewhere in the pioneer zone. Furthermore, recruits grew to be on average three times greater in mass inside of the structures than in the neighboring ambient environment. The success of this restoration design may be attributed to the combination of three factors: (1) enhanced seed retention, (2) suppressed mortality, and (3) accelerated growth rates on the elevated surfaces generated by the artificial structures. We argue that restoration approaches similar to the one shown here, wherein the conditions for natural establishment are actively mimicked to promote vegetation development, may serve as promising tools in many biogeomorphic ecosystems, ranging from coastal to arid ecosystems. [ABSTRACT FROM AUTHOR]

Microtopographic variation is ubiquitous throughout lowland Amazonia, and it may impart patterns of species richness and abundance, and perhaps community compositional changes. To date, no studies have determined the degree to which lowland microtopography influences forest canopy diversity. We developed the first high-resolution maps of forest canopy diversity in Amazonia, focusing on four landscapes on two river systems in Peru. Spectroscopic images were acquired using the Carnegie Airborne Observatory combined with a new method based on spectral species to map α - and β-diversity. We analyzed spatial patterns in diversity with respect to floodplain and terrace (terra firme) surfaces and in upriver and downriver locations with contrasting landscape morphologies. We found slightly lower average a-diversity in floodplains, but with greater variance than in terrace communities caused by the floodplain mix of swamp forests, anoxic low-diversity ecosystems, and high-diversity areas. b-diversity estimated with the Bray-Curtis dissimilarity (BC) was strongly related to microtopography, with floodplains showing higher internal compositional dissimilarity than terraces. Throughout all landscapes, remotely mapped BC within terrace environments ranged from 0.25 to 0.43, but these values increased 30-77% on floodplains. Upriver landscapes characterized by higher terraces showed more distinct community turnover than did their downstream counterparts. We conclude that microtopography strongly influences β-diversity throughout the study landscapes, but terrain is weakly associated with variation in α-diversity. We uncover the importance of microtopography in determining species composition in lowland Amazonia and highlight the value of imaging spectroscopy for biodiversity research and conservation. [ABSTRACT FROM AUTHOR]

The conservation of species at risk of extinction requires data to support decisions at landscape to regional scales. There is a need for information that can assist with locating suitable habitats in fragmented and degraded landscapes to aid the reintroduction of at-risk plant species. In addition, desiccation and water stress can be significant barriers to the success of at-risk plant reintroduction programs. We examine how airborne light detection and ranging (LiDAR) data can be used to model microtopographic features that reduce water stress and increase resource availability, providing information for landscape planning that can increase the success of reintroduction efforts for a dryland landscape in Hawaii. We developed a topographic habitat-suitability model (HSM) from LiDAR data that identifies topographic depressions that are protected from prevailing winds (high-suitability sites) and contrasts them with ridges and other exposed areas (low-suitability sites). We tested in the field whether high-suitability sites had microclimatic conditions that indicated better-quality habitat compared to low-suitability sites, whether plant-response traits indicated better growing conditions in high-suitability sites, whether the locations of individuals of existing atrisk plant species corresponded with our habitat-suitability classes, and whether the survival of planted individuals of a common native species was greater in high-suitability, compared to low-suitability, planting sites. Mean wind speed in a high-suitability field site was over five times lower than in a low-suitability site, and soil moisture and leaf wetness were greater, indicating less stress and greater resource availability in high-suitability areas. Plant height and leaf nutrient content were greater in high-suitability areas. Six at-risk species showed associations with high-suitability areas. The survival of planted individuals was less variable among high-suitability plots. These results suggest that plant establishment and survival is associated with the habitat conditions identified by our model. The HSM can improve the survival of planted individuals, reduce the cost of restoration and reintroduction programs through targeted management activities in high-suitability areas, and expand the ability of managers to make landscape-scale decisions regarding land-use, land acquisition, and species recovery. [ABSTRACT FROM AUTHOR]

The article presents a study on tussock formation by sedges. It mentions the impact of hydroperiod and nutrients to the global phenomenon. It states that Carex stricta was investigated and suggests the structural adaptation to anoxic conditions. It also notes on the restoration of wetland microtopography.

The article explores how ecological theory predicts habitat heterogeneity into restoration sites. It also examines how topographic heterogeneity affects higher trophic levels. In this context, the author mentioned that the southern California restoration experiment tested effects of tidal creek networks and pools on trophic structure of salt marsh habitat and high-tide use by two regionally dominant fish species. These include California killifish or Fundulus parvipinnis and longjaw mudsucker or Gillichthys mirabilis. Tidal creeks are expected to function as conduits that would enhance connectivity between subtidal and intertidal habitat and pools to serve as microhabitat oases for fishes.

The article presents a study that investigates the effects of several treatments on the performance of N-fixing lichens that were planted in a disturbed soil crust in Colorado plateau. It offers details of the method of the study that uses four kinds of treatments to observe their responses to nutrients. It outlines the result of the study which indicates that the microtopographic differences in erosion, microclimate, and nutrient regimes illustrate the variability of the performance of lichen.