Slower Recovery Rate Research Articles

Reproductive capacity of an endangered and recovering population of humpback whales in the Southern Hemisphere

Estimating demographic parameters is essential to assessing the recovery potential of severely depleted populations of marine mammal species such as the baleen whales, which were decimated by commercial whaling of the past century. The Oceania humpback whaleMegaptera novaeangliaepopulation is classified as endangered by the IUCN because of low numbers and a slow recovery rate. Nevertheless, an anomalously strong increase has recently been detected in the New Caledonia breeding population. To determine the drivers of population growth, reproductive parameters were estimated for the first time for a humpback whale population of Oceania. Based on an extensive monitoring program (1995-2018), recapture histories were reconstructed for 607 females and incorporated in multi-event capture-recapture models. As the females’ ages were generally unknown (87%), 2 models with contrasting age scenarios were investigated. For females of unknown age, the mature scenario assumed maturity at the first encounter, while the immature scenario assumed immaturity within 7 yr after the first encounter, unless the female was encountered breeding. These models respectively resulted in a calving interval of 1.49 yr (95% CI: 1.21-2.08) or 2.83 yr (95% CI: 2.28-3.56) and a calving rate of 0.67 or 0.35. The relatively high calving rate modelled by the mature model is consistent with high pregnancy rates recently observed in the migratory corridors of the Kermadec Islands and on the feeding grounds of the Antarctic Peninsula. Therefore, our results suggest that the recovery of the New Caledonia humpback whale population from past exploitation may be partially driven by an increased reproductive capacity.

A mechanistic, stigmergy model of territory formation in solitary animals: Territorial behavior can dampen disease prevalencebut increase persistence.

Although movement ecology has leveraged models of home range formation to explore the effects of spatial heterogeneity and social cues on movement behavior, disease ecology has yet to integrate these potential drivers and mechanisms of contact behavior into a generalizable disease modeling framework. Here we ask how dynamic territory formation and maintenance might contribute to disease dynamics in a territorial, solitary predator for an indirectly transmitted pathogen. We developed a mechanistic individual-based model where stigmergy-the deposition of signals into the environment (e.g., scent marking, scraping)-dictates local movement choices and long-term territory formation, but also the risk of pathogen transmission. Based on a variable importance analysis, the length of the infectious period was the single most important variable in predicting outbreak success, maximum prevalence, and outbreak duration. Host density and rate of pathogen decay were also key predictors. We found that territoriality best reduced maximum prevalence in conditions where we would otherwise expect outbreaks to be most successful: slower recovery rates (i.e., longer infectious periods) and higher conspecific densities. However, for slower pathogen decay rates, stigmergy-driven movement increased outbreak durations relative to random movement simulations. Our findings therefore support a limited version of the "territoriality benefits" hypothesis-where reduced home range overlap leads to reduced opportunities for pathogen transmission, but with the caveat that reduction in outbreak severity may increase the likelihood of pathogen persistence. For longer infectious periods and higher host densities, key trade-offs emerged between the strength of pathogen load, the strength of the stigmergy cue, and the rate at which those two quantities decayed; this finding raises interesting questions about the evolutionary nature of these competing processes and the role of possible feedbacks between parasitism and territoriality. This work also highlights the importance of considering social cues as part of the movement landscape in order to better understand the consequences of individual behaviors on population level outcomes.

Predicting the Distribution of Indicator Taxa of Vulnerable Marine Ecosystems in the Arctic and Sub-arctic Waters of the Nordic Seas

In the deep waters of the Nordic Seas and adjacent areas, several benthic habitats such as cold-water coral reefs, coral gardens, and deep-sea sponge aggregations have been classified as vulnerable marine ecosystems (VMEs), due to their uniqueness, limited spatial extent, physical fragility, and slow recovery rate. In the last decade observations carried out by habitat mapping programmes in Norway, Iceland and more recently in the Faroe Islands have substantially increased knowledge on the distribution of VMEs in the Nordic Seas. Nevertheless, large areas have not been explored due to the cost and logistics of obtaining observations in the deep-sea. Species distribution models can be used to predict the distribution of VMEs and their indicator species. Here we present the predicted distribution of 44 VME indicator taxa including 20 sponges, 17 cold-water corals and 7 seapens in the Nordic Seas based on data compiled and models developed by the NovasArc project (2016-2018). Models for 44 VME indicator species were developed using a maximum entropy approach (MaxEnt) using an extensive database compiled from habitat mapping surveys, by-catch data from bottom fish surveys, and records from reports and peer reviewed publications. Modeled distributions showed good agreement with observations. Niche overlap measures were used to identify seven groups and four subgroups of VME indicator taxa that co-occur. These were consistent with the species composition of known biotopes in the study area. A VME Index that combine the predictions for all VME indicator species was computed to identify particularly valuable and vulnerable ecosystems that should be targets of further exploration and conservation efforts. Such areas were identified at shelf break and slope off Iceland, the Faroe Islands, and central Norway, and the continental shelf off southern Greenland. The predicted distribution of VMEs in arctic and sub-arctic waters allows for the evaluation of interactions with fisheries and other anthropogenic activities and provides an important input for managers.

Potential of Genome-Wide Association Studies and Genomic Selection to Improve Productivity and Quality of Commercial Timber Species in Tropical Rainforest, a Case Study of Shorea platyclados

Shorea platyclados (Dark Red Meranti) is a commercially important timber tree species in Southeast Asia. However, its stocks have dramatically declined due, inter alia, to excessive logging, insufficient natural regeneration and a slow recovery rate. Thus, there is a need to promote enrichment planting and develop effective technique to support its rehabilitation and improve timber production through implementation of Genome-Wide Association Studies (GWAS) and Genomic Selection (GS). To assist such efforts, plant materials were collected from a half-sib progeny population in Sari Bumi Kusuma forest concession, Kalimantan, Indonesia. Using 5900 markers in sequences obtained from 356 individuals, we detected high linkage disequilibrium (LD) extending up to >145 kb, suggesting that associations between phenotypic traits and markers in LD can be more easily and feasibly detected with GWAS than with analysis of quantitative trait loci (QTLs). However, the detection power of GWAS seems low, since few single nucleotide polymorphisms linked to any focal traits were detected with a stringent false discovery rate, indicating that the species’ phenotypic traits are mostly under polygenic quantitative control. Furthermore, Machine Learning provided higher prediction accuracies than Bayesian methods. We also found that stem diameter, branch diameter ratio and wood density were more predictable than height, clear bole, branch angle and wood stiffness traits. Our study suggests that GS has potential for improving the productivity and quality of S. platyclados, and our genomic heritability estimates may improve the selection of traits to target in future breeding of this species.

Lagging recovery for tropical forests

Ecology Tropical forest aboveground carbon (AGC) stocks have yet to recover from the extremely hot and dry weather associated with the 2015–2016 El Nino event. Wigneron et al. used low-frequency microwave satellite data to monitor AGC changes from 2014 to 2017. By the end of 2017, AGC stocks had not reached 2014 predrought levels and continued to decline in some areas. The slow rate of recovery could be due, in part, to enhanced forest mortality and/or unaccounted deforestation and degradation, specifically in African humid forests. Such continuity in long-term records may improve understanding of climate change on ecosystems. Sci. Adv. 10.1126/sciadv.aay4603 (2020).

Topical application of silk fibroin-based hydrogel in preventing hypertrophic scars

Current medications for the treatment of hypertrophic scars suffer from bottlenecks of limited therapeutic efficacy and a slow recovery rate. Silk fibroin (SF) has gained attention for its ability to promote wound healing in burns and cutaneous wounds, but its therapeutic effects against hypertrophic scar have not been thoroughly investigated. We prepared SF-based hydrogels (SFHs) with various SF concentrations (1.5 %, 3 %, and 6 %) and characterized their physicochemical properties. Cell experiments showed that these SFHs had favorable biocompatibility in vitro. Further animal experiments in rabbits revealed that the SFH (3 %)-treated group achieved scars on their ears that were thinner and significantly lighter in color compared with the negative control group. Moreover, treatment with SFHs reduced the density and led to the orderly arrangement of collagen fibers. It was found that the therapeutic effects of SFHs were attributed to the reduced expression levels of α-smooth muscle actin. These results are the first to demonstrate that SFH can be exploited as an effective therapeutic agent for the treatment of hypertrophic scars.

Plant diversity, net primary productivity and soil nutrient contents of a humid subtropical grassland remained low even after 50 years of post-disturbance recovery from coal mining.

Assessment of environmental impact of coal mining on natural ecosystems and monitoring of subsequent ecological restoration process of mined areas are essential for devising reclamation strategies for mining-affected landscapes. The present study was designed to assess the post-disturbance recovery of vegetation, primary productivity and soil nutrient build-up of a humid subtropical grassland ecosystem following coal mining activities. Two replicate sites each for the undisturbed grasslands (UG), mining-affected (MG) and recovering grasslands of 15 (RG15) and 50 (RG50) years old were selected. There was a distinct pattern of species colonization and replacement during different years of recovery. Species richness, biomass, net primary productivity and soil pH declined following disturbance but increased with recovery age. Soil organic C and total N were high in the MG sites but significantly declined with recovery age. Soil total P and exchangeable K and Mg were low even at the 50th year of recovery indicating extremely slow recovery rate of these nutrients. Considering the extremely slow natural recovery of vegetation and soil nutrients, it is recommended to carry out artificial or aided vegetation restoration using native grass species tolerant to disturbance. Six species which are well-adapted to the mining environment and were present in both undisturbed and mining-affected recovering grasslands, viz. Arundinella khaseana, Cyanotis vaga, Eragrostis nigra, Polygonum bistorta and Fimbristylis hookeriana, are recommended for aided vegetation regeneration.

Short- and long-term effects of ponderosa pine fuel treatments intersected by the Egley Fire Complex, Oregon, USA

BackgroundFuel treatments are widely used to alter fuels in forested ecosystems to mitigate wildfire behavior and effects. However, few studies have examined long-term ecological effects of interacting fuel treatments (commercial harvests, pre-commercial thinnings, pile and burning, and prescribed fire) and wildfire. Using annually fitted Landsat satellite-derived Normalized Burn Ratio (NBR) curves and paired pre-fire treated and untreated field sites, we tested changes in the differenced NBR (dNBR) and years since treatment as predictors of biophysical attributes one and nine years after the 2007 Egley Fire Complex in Oregon, USA. We also assessed short- and long-term fuel treatment impacts on field-measured attributes one and nine years post fire.ResultsOne-year post-fire burn severity (dNBR) was lower in treated than in untreated sites across the Egley Fire Complex. Annual NBR trends showed that treated sites nearly recovered to pre-fire values four years post fire, while untreated sites had a slower recovery rate. Time since treatment and dNBR significantly predicted tree canopy and understory green vegetation cover in 2008, suggesting that tree canopy and understory vegetation cover increased in areas that were treated recently pre fire. Live tree density was more affected by severity than by pre-fire treatment in either year, as was dead tree density one year post fire. In 2008, neither treatment nor severity affected percent cover of functional groups (shrub, graminoid, forb, invasive, and moss–lichen–fungi); however, by 2016, shrub, graminoid, forb, and invasive cover were higher in high-severity burn sites than in low-severity burn sites. Total fuel loads nine years post fire were higher in untreated, high-severity burn sites than any other sites. Tree canopy cover and density of trees, saplings, and seedlings were lower nine years post fire than one year post fire across treatments and severity, whereas live and dead tree basal area, understory surface cover, and fuel loads increased.ConclusionsPre-fire fuel treatments effectively lowered the occurrence of high-severity wildfire, likely due to successful pre-fire tree and sapling density and surface fuels reduction. This study also quantified the changes in vegetation and fuels from one to nine years post fire. We suggest that low-severity wildfire can meet prescribed fire management objectives of lowering surface fuel accumulations while not increasing overstory tree mortality.

The circadian system modulates the rate of recovery of systolic blood pressure after exercise in humans.

Recovery rates of systolic blood pressure (BP) and heart rate (HR) after exercise have been used to assess cardiovascular fitness, and slower recovery rates are predictors of coronary heart disease and cardiac mortality. The endogenous circadian system is known to modulate BP and HR at rest and during exercise. Here, we examined whether the post-exercise recovery rates of BP and HR are also under circadian control. Twelve healthy adults (mean age = 26 ± 6 (SD) years; 6 female) participated in a 240 h forced desynchrony protocol in dim light where all behaviors, including 15 min cycle exercise tests at 60% maximal HR, were uniformly distributed across the circadian cycle. Circadian phases were assigned based on the rhythm of core body temperature. For each session, HR was measured continuously, and BP every 3-5 min throughout baseline, exercise, and recovery. Recovery was quantified as the proportional return to pre-exercise baseline levels following exercise ([peak exercise-recovery]/[peak exercise-baseline) × 100%], whereby 100% represents full recovery to baseline). There was a significant circadian rhythm in systolic BP recovery, with fastest recovery at the circadian phase corresponding to late afternoon (equivalent to ~5 pm) and slower recovery across the early morning (~8:30 am; p = 0.029, peak-to-trough: 9.2%). There were no significant circadian variations in post-exercise recovery rates of diastolic BP or HR. The circadian system modulates the rate of recovery of systolic BP after exercise with fastest recovery in the biological afternoon. These data could have implications for exercise prescription and interpretation of clinical tests of stress recovery.

Altered cortical morphology in patients with chronic shoulder pain

Shoulder pain is a common condition associated with slow recovery and high recurrence rates. Persistent pain may lead to structural brain changes that may further promote pain chronification. The present study addressed whether abnormal changes in cortical surface structure exist in patients with chronic shoulder pain of myofascial origin and whether such changes would be related to pain measures. Brain structural MRIs were obtained in 22 patients with chronic pain in the bilateral upper trapezius muscles and in 22 healthy controls. Cortical thickness, gyrification index and sulcal depth were assessed together with pain measures. Shallower sulcal depth was found in patients in the right central sulcus, posterior insula, inferior frontal and dorsomedial prefrontal cortices, precuneus, and the middle temporal cortex, and in the left medial orbitofrontal cortex. Negative correlations were found between the right central sulcus and pain intensity and between the left medial orbitofrontal cortex and pain affect. Cortical thickness or gyrification index did not differ significantly between the two groups. The afflicted cortical regions constitute interacting networks responsible for sensory, affective and cognitive dimensions of the pain experience.

Minilifting technique for treatments of the lower third of the face and anterior cervical neck with tumescent anesthesia

Minimally invasive surgical techniques with a low rate of complications and rapid return to daily activities are in high demand for dermatological procedures and include lasers, microfocused ultrasound, botulinum toxin, suture strings, and filling techniques with hyaluronic acid. The facelift, on the other hand, has been criticized for complications such as bruising, relatively slow recovery rates (lasting up to a month), facial nerve lesions, and flap necrosis. Earliest descriptions of the facelift technique described a procedure associated with skin traction and detachment. However, authors did not describe a method for SMAS plication, which is still somewhat controversial. Describe a surgical technique that reduce the signs of aging on the lower third of the face and neck with low rate of complications. The minilifting technique described herein is capable of repositioning the superficial muscular aponeurotic system (SMAS) and removing excess skin from the neck and lower third of the face with minimal detachment, local tumescent anesthesia, a few complications, and a relatively fast return to daily activities (15 days). Performance of a deep dissection and excision of part of the SMAS with posterior sutures is believed to be an optimal approach, whereas authors believe that a superficial dissection is safer and provides similar outcomes compared to deep dissection. This procedure produces extremely natural and long-lasting results.

Impact of forest thinning on the dynamics of litterfall derived 137Cs deposits in coniferous forest floor after Fukushima accident

The effects of a 50% forest thinning intensity on Fukushima-derived 137Cs deposition by litterfall and its discharge by runoff in hillslope coniferous forest were monitored using four litterfall traps and a hillslope erosion plot. The observation was underway during the pre-and post-thinning periods. Results demonstrated that during the pre-thinning period a total 150 ± 13 g m−2 of litterfall deposited about 924 ± 69 Bq m−2 of 137Cs. This accounts for 11% of the local 137Cs fallout recorded for the study site in the aftermath of the accident. After thinning, both litterfall and 137Cs increased by more than six- and two-fold, respectively. This is possibly owing to the slow individual tree recovery rate assisted by the change on the running space provided by canopy openings, which can accelerate even the normal gust wind to gain damaging power on the unshielded mechanically injured parts of the contaminated residual trees. In both cases, litterfall generally transferred about 37% (3 ± 0.2 kBq m−2) of the local 137Cs fallout onto the forest floor over the observation period. The eroded litter-associated 137Cs increased by about a factor of two after thinning, which only accounted for less than 1% of 137Cs deposited by litterfall. This implies that the forest floor retains 137Cs and remains contaminated regardless of the size of the eroded litter material. But this could become a potential secondary contamination source for the downstream resources such as water bodies and villages, especially at the time of flooding, which in turn calls a serious attention in designing decontamination schemes.

Image Analysis to Monitor Experimental Trampling and Vegetation Recovery in Icelandic Plant Communities

With growing tourism in natural areas, monitoring recreational impacts is becoming increasingly important. This paper aims to evaluate how different trampling intensities affect some common Icelandic plant communities by using digital photographs to analyze and quantify vegetation in experimental plots and to monitor vegetation recovery rates over a consecutive three-year period. Additionally, it seeks to evaluate the use of image analysis for monitoring recreational impact in natural areas. Experimental trampling was conducted in two different sites representing the lowlands and the highlands in 2014, and the experimental plots were revisited in 2015, 2016, and 2017. The results show that moss has the highest sensitivity to trampling, and furthermore has a slow recovery rate. Moss-heaths in the highlands also show higher sensitivity and slower recovery rates than moss-heaths in the lowlands, and grasslands show the highest resistance to trampling. Both methods tested, i.e., Green Chromatic Coordinate (GCC) and Maximum Likelihood Classification (MLC), showed significant correlation with the trampling impact. Using image analysis to quantify the status and define limits of use will likely be a valuable and vital element in managing recreational areas. Unmanned aerial vehicles (UAVs) will add a robust way to collect photographic data that can be processed into vegetation parameters to monitor recreational impacts in natural areas.

Ag nanoparticles-decorated α-MoO3 nanorods for remarkable and rapid triethylamine-sensing response boosted by pulse-heating technique

Surface interaction between the target vapor and metal oxides can be boosted by noble metal-decorating. The surface effect can contribute to high gas-response but leads to slow recovery rate. In this paper, the Ag nanoparticles (NPs) with sizes about ∼20 nm were uniformly coated onto acidic α-MoO3 nanorods through a wet-chemical reduction method at 50 °C. After sensing assessment for triethylamine (TEA), the optimal sensor based on 2 mol% AgNPs-decorated α-MoO3 nanorods shows the highest response (Ra/Rg = 408.6 to 100 ppm TEA) at 200 °C among the pure α-MoO3 and the other AgNPs/α-MoO3 nanorods. In addition, this sensor depicts a fast response time (3 s) towards 100 ppm TEA, but its recovery time is rather long. The recovery time can be improved (less than 2 min) using pulse-heating strategy at 300 °C in air for 1 min. Moreover, this sensor displays an ultrahigh selectivity towards TEA at the existence of many interfering gases (including NH3, H2S, formaldehyde, ethanol, isopropanol, acetone, and toluene). On basis of the depletion layer model and spillover effect of AgNPs, the enhanced sensing response towards TEA can be illustrated in detail. This work may open an avenue for designing gas sensor with high response and fast detection rate.

Advancing Research for the Management of Long-Lived Species: A Case Study on the Greenland Shark

Long-lived species share life history traits such as slow growth, late maturity, and low fecundity, which lead to slow recovery rates and increase a population’s vulnerability to disturbance. The Greenland shark (Somniosus microcephalus) has recently been recognized as the world’s longest-lived vertebrate, but many questions regarding its biology, physiology, and ecology remain unanswered. Here we review how current and future research will fill knowledge gaps about the Greenland shark and provide an overall framework to guide research and management priorities for this species. Key advances include the potential for specialised ageing techniques and demographic studies to shed light on the distribution and age-class structure of Greenland shark populations. Advances in population genetics and genomics will reveal key factors contributing to the Greenland shark’s extreme longevity, range and population size, and susceptibility to environmental change. New tagging technologies and improvements in experimental and analytical design will allow detailed monitoring of movement behaviours and interactions among Greenland sharks and other marine species, while shedding light on habitat use and susceptibility to fisheries interactions. Interdisciplinary approaches, such as the combined use of stable isotope analysis and high-tech data-logging devices (i.e. accelerometers and acoustic hydrophones) have the potential to improve knowledge of feeding strategies, predatory capabilities, and the trophic role of Greenland sharks. Measures of physiology, including estimation of metabolic rate, as well as heart rate and function, will advance our understanding of the causes and consequences of long lifespans. Determining the extent and effects of current threats (as well as potential mitigation measures) will assist the development of policies, recommendations, and actions relevant for the management of this potentially vulnerable species. Through an interdisciplinary lens, we propose innovative approaches to direct the future study of Greenland sharks and promote the consideration of longevity as an important factor in research on aquatic and terrestrial predators.

Estimation of Supply Chain Network Disruption of Companies Across the Country Affected by the Nankai Trough Earthquake Tsunami in Kochi City

Using various types of big data on the Nankai Trough earthquake and tsunami that struck Kochi, we describe a method of simulating how economic damage to inter-enterprise transactions propagates through the supply chain and how subsequent recovery occurs. First, we enter the human losses and material damage caused by the earthquake and tsunami to estimate the material damage and labor capital loss of each enterprise based on the position information of employees. Next, we simulate the damage repercussions regarding production capacity over the entire supply chain through many tiers, and extract bottlenecks of company risk within the supply chain. It was found that bottleneck companies tend have a slow recovery rate as compared to other affected companies. They also had a tendency of being in the construction, manufacturing, wholesale, and service industry sectors, and small in scale.

Time Course of Recovery Following Resistance Exercise with Different Loading Magnitudes and Velocity Loss in the Set.

The aim of this study was to compare the time course of recovery following four different resistance exercise protocols in terms of loading magnitude (60% vs. 80% 1RM—one-repetition maximum) and velocity loss in the set (20% vs. 40%). Seventeen males performed four different protocols in full squat exercise, which were as follows: (1) 60% 1RM with a velocity loss of 20% (60-20), (2) 60% 1RM with a velocity loss of 40% (60-40), (3) 80% 1RM with a velocity loss of 20% (80-20), and (4) 80% 1RM with a velocity loss of 40% (80-40). Movement velocity against the load that elicited a 1 m·s−1 velocity at baseline measurements (V1-load), countermovement jump (CMJ) height, and sprint time at 20 m (T20) were assessed at Pre, Post, 6 h-Post, 24 h-Post, and 48 h-Post. Impairments in V1-load were significantly higher for 60-40 than other protocols at Post (p < 0.05). The 60-20 and 80-40 protocols exhibited significant performance impairments for V1-load at 6 h-Post and 24 h-Post, respectively (p < 0.05). CMJ height remained decreased for 60-20 and 60-40 until 24 h-Post (p < 0.001–0.05). Regarding T20, the 80-40 protocol resulted in higher performance than 60-40 at 24 h-Post and the 80-20 protocol induced a greater performance than 60-40 protocol at 48 h-Post (p < 0.05). A higher velocity loss during the set (40%) and a lower relative load (60% 1RM) resulted in greater fatigue and slower rate of recovery than lower velocity loss (20%) and higher relative load (80% 1RM).

Evidence for \u2018critical slowing down\u2019 in seagrass: a stress gradient experiment at the southern limit of its range

The theory of critical slowing down, i.e. the increasing recovery times of complex systems close to tipping points, has been proposed as an early warning signal for collapse. Empirical evidence for the reality of such warning signals is still rare in ecology. We studied this on Zostera noltii intertidal seagrass meadows at their southern range limit, the Banc d’Arguin, Mauritania. We analyse the environmental covariates of recovery rates using structural equation modelling (SEM), based on an experiment in which we assessed whether recovery after disturbances (i.e. seagrass & infauna removal) depends on stress intensity (increasing with elevation) and disturbance patch size (1 m2vs. 9 m2). The SEM analyses revealed that higher biofilm density and sediment accretion best explained seagrass recovery rates. Experimental disturbances were followed by slow rates of recovery, regrowth occurring mainly in the coolest months of the year. Macrofauna recolonisation lagged behind seagrass recovery. Overall, the recovery rate was six times slower in the high intertidal zone than in the low zone. The large disturbances in the low zone recovered faster than the small ones in the high zone. This provides empirical evidence for critical slowing down with increasing desiccation stress in an intertidal seagrass system.

Drivers of biomass recovery in a secondary forested landscape of West Africa

The rapidly growing human population in West Africa has generated increasing demand for agricultural land and forest products. Consequently 90% of the original rainforest cover has now disappeared and the remainder is heavily fragmented and highly degraded. Although many studies have focused on carbon stocks and fluxes in intact African forests, little information exists on biomass recovery rates in secondary forests. We studied a chronosequence of 96 secondary and old-growth forest fragments (0.2 ha each) where 32.103 trees with Diameter at Breast Height >2.5 cm have been censused. We modelled the biomass recovery trajectories in a time-explicit Bayesian framework and tested the effect on recovery rates of a large set of covariates related to the physical environment, plot history, and forest connectivity. Recovery rate trajectory is highly non-linear: recovery rates accelerated from 1 to 37 years, when biomass recovery reached 4.23 Mg·ha−1·yr−1, and decelerated afterwards. We predict that, on average, 10%, 25% and 50% of the old-growth forest biomass is respectively recovered 17, 30, and 51 years after abandonment. Recovery rates are strongly shaped by both the number of remnant trees (residuals of the former old-growth forest) and the previous crop cultivated before abandonment. The latter induced large differences in the time needed to recover 50% of an old-growth forest biomass: from 38 years for former Yam fields up to 86 years for former rice fields. Our results emphasize (i) the very slow recovery rates of West African forests, as compared to Neotropical forests (ii) the long-lasting impacts of past human activities and management choices on ecosystem biomass recovery in West African degraded forests.

Miniature baited remote underwater video (mini-BRUV) reveals the response of cryptic fishes to seagrass cover

Seagrass habitats worldwide are degrading and becoming fragmented, threatening the important ecosystem services they provide. Fauna associated with seagrasses, particularly cryptic species, are expected to respond to these changes, but are difficult to detect at ecologically meaningful scales using non-extractive techniques. We used a small, wide-angle camera (GoPro) and a small quantity of bait positioned within the canopy of Posidonia australis meadows in Jervis Bay, New South Wales to assess the response of fishes to seagrass cover. We saw a clear positive relationship with the condition of P. australis; a high cover of this seagrass had positive effects on the diversity and abundance of cryptic fauna. Our findings highlight ecosystem shifts associated with the loss and fragmentation of biogenic habitat. These changes are of particular relevance for P. australis meadows given their current status as an endangered ecological community in several locations in NSW and their slow rate of recovery from disturbance.