Future directions of mangrove modeling: IBMbedding

info:eu-repo/semantics/publishe

Individual-based modeling of mangrove forest growth: MesoFON – Recent calibration and future direction

We introduce individual-based models (IBMs) of mangrove forests and criticize the tasks for their development recommended previously for being mostly related to natural threats. This is contrasted with our perspective that the key research question of today's models should be to mitigate anthropogenic threats. Core objective (1) of this article is to provide a review of mangrove threats prioritizing solution-oriented IBM approaches. Because species-specific calibration of IBMs is time-consuming, efficiency is crucial. Globally, we identify an urgent need to parametrize Asian mangrove species. We suggest IBMs to unveil management scenarios with maximum sustainable timber yield to prevent mangrove conversion and over-exploitation. The key model purpose regarding natural threats is to govern the management of mangrove forest stability for coastal protection using a combination of windthrow models and IBMs. We argue for the embedding of IBMs in ecosystem models to achieve purposes regarding eutrophication and altered hydrology/sedimentation. Core objective (2) is to describe the development of the new IBM mesoFON from a task-to a solution-oriented model. Initially, the interaction of lateral crown displacement and hurricane impacts was examined with mesoFON. Later, we introduced propagule production & local dispersal with the task to close the tree life cycle. Here, we describe the change in purpose of mesoFON accompanying its calibration for Rhizophora apiculata in Malaysia. For this we applied a Genetic Algorithm optimizer, used mesoFON as a “way-back machine”, initialized it with observed tree diameters/positions and shrank the trees backwards in time. Objective(3) is to describe mesoFON's future direction: Embedding in the General Ecosystem Model (Fitz et al. 1996) and targeting the solution of threats at larger spatial scales. Finally, we demonstrate that the new model simulates overland waterflow qualitatively right even in benchmark settings.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Tree parameters

Tree parameters (stem diameter, height and crown radii in eight cardinal directions) for 12 mangrove forest stands located along a soil salinity gradient within the mangrove forest of the Lagoon of La Mancha, located in the central Gulf Coast of Mexico. The data set was used to study the responses of tree crowns to asymmetric neighbourhood pressure and dominant wind direction. The data set was created in collaboration between The Institute of Ecology (INECOL, Mexico), and the Technische Universitaet Dresden (Dresden, Germany), under the scope of the Coastal Research Network for Environmental Change (CREC), financed by the European Commission

Modelling mangrove-mudflat dynamics with a coupled individual-based-hydro-morphodynamic model

As climate-change-driven extremes potentially make coastal areas more vulnerable, mangroves can help sustainably protect the coasts. There is a substantial understanding of both mangrove dynamics and hydro-morphodynamic processes. However, the knowledge of complex eco-geomorphic interactions with physical-environmental stressors remains lacking. We introduce a novel coupled modelling approach consisting of an individual-based mangrove (mesoFON) and a process-based hydromorphodynamic model (Delft3D-FM). This coupled model is unique because it resolves spatiotemporal processes, including tidal, seasonal, and decadal environmental changes (water level, flow, sediment availability, and salinity) with full life-stages (propagule, seedling, sapling, mature) mangrove interaction. It allows us to mechanistically simulate forest expansion, retreat, and colonisation influenced by and with feedback on physical-environmental drivers. The model is applied in a schematized mixed fluvial-tidal deltaic mangrove forest in dominantly muddy sediment inspired by the prograding delta of Porong, Indonesia. Model results successfully reproduce observed mangrove extent development, age-height relationship, and morphodynamic delta features.Coastal Engineerin

An Evaluation of the Plant Density Estimator the Point-Centred Quarter Method (PCQM) Using Monte Carlo Simulation.

In the Point-Centred Quarter Method (PCQM), the mean distance of the first nearest plants in each quadrant of a number of random sample points is converted to plant density. It is a quick method for plant density estimation. In recent publications the estimator equations of simple PCQM (PCQM1) and higher order ones (PCQM2 and PCQM3, which uses the distance of the second and third nearest plants, respectively) show discrepancy. This study attempts to review PCQM estimators in order to find the most accurate equation form. We tested the accuracy of different PCQM equations using Monte Carlo Simulations in simulated (having 'random', 'aggregated' and 'regular' spatial patterns) plant populations and empirical ones.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The mangrove forest dynamics model mesoFON

This study presents mesoFON, an individual-based mangrove forest dynamics model that advances beyond current models by describing crown plasticity of mangrove trees. The crown plasticity routines take advantage of the fields-of-neighborhood (FON) approach and account for the trunk bending and the differential side branch growth mechanism. Competition for above-/below-ground resources is dealt with separately in this model. Offspring production depends on tree growth and rises with tree ontogeny. An extensive sensitivity analysis revealed that mesoFON resembles the behavior of known mangrove forest dynamics and is ready for application. In this study we exposed two plant functional types (PFTs) of the red mangrove (Rhizophora mangle L.) either in monoculture or as a community to two disturbance regimes, namely (1) without disturbances and (2) with hurricane impacts returning every 5 years. While one functional type possesses plastic crowns, the other PFT has rigid crowns. For the first time, long-term interaction of lateral crown displacement and disturbance was examined using a comprehensive comparative analysis including point patterns and canopy coverage. In the monoculture experiments disturbance strongly promoted the beneficial effects of crown plasticity. Without disturbance crown movements merely increased stand-based stem volume by 6.7% despite considerable displacement distances. We attribute this to the overall high competitive strength that constrained the effects of plasticity in the dense stands. Yet, in disturbed stands the plastic behavior raised stem volume and tree density by 12.5% and 7.5%, respectively, as a result of substantially reduced local competition (by 20.1%). In this treatment crown shifts are particularly advantageous because of their contribution to gap closure. Generally, the Clark Evans aggregation index of crown centers tended to be higher than that of stem bases indicating a more regular distribution of crown centers. The same was true for the canopy coverage of crowns located at their centers implying better space usage by shifted crowns. Pair-correlation functions revealed a plasticity-induced trend toward more regular distribution at low tree-to-tree distances and less aggregation at intermediate distances. The trend was stronger in disturbed communities. The plastic PFT was finally able to out-compete the rigid PFT in all community experiments. Hurricane impacts, however, accelerated the time to the extinction of the rigid PFT by a factor of 2.4. © 2014 Elsevier B.V.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Solving the fourth-corner problem: Forecasting ecosystem primary production from spatial multispecies trait-based models

The dataset contains environmental (Excel Sheet 1), species counts (Excel Sheet 2), and functional trait (Excel Sheet 3) data collected from the Sundarbans mangrove forest in Bangladesh