Stratified Random Design Research Articles

Abstract GS03-06: Genomic and transcriptomic profiling of primary tumors from patients with HR+, HER2-, node-positive, high-risk early breast cancer in the monarchE trial

Abstract Background Two years of adjuvant abemaciclib combined with endocrine therapy (ET) resulted in significant and clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in patients (pts) with HR+, HER2-, node-positive, high-risk early breast cancer in the monarchE trial (NCT03155997). Abemaciclib benefit was sustained beyond the completion of treatment (tx) with deepening magnitude of absolute benefit in IDFS and DRFS at 5 years. Here, we evaluate comprehensive molecular profiling of archived primary tumor tissue and association with clinical outcomes. Methods For biomarker analysis, a proportionally stratified random sampling case-cohort design was utilized to include all patients who experienced an IDFS event at a pre-specified interim analysis with a median follow up of 54 months. A cohort of 895 pts (189 with IDFS event) in the abemaciclib + ET arm was matched 1:1 with 903 pts (270 with IDFS event) in the ET arm. Baseline primary tumor samples underwent exome-capture RNA sequencing (RNAseq; n=1324, 23% intent-to-treat (ITT) population) and paired tumor-normal (germline blood samples) whole-exome sequencing (WES; n=1234, 22% ITT population). Expression-based intrinsic subtypes (i.e., luminal A (LumA), luminal B (LumB), HER2-enriched (HER2E), basal- and normal-like) were characterized using the Absolute Intrinsic Molecular Subtyping model. The 21-gene expression signature score (Oncotype DX test) was inferred from RNAseq; samples were categorized into lower (0-25) and high (26-100) risk groups. To investigate associations of biomarkers with abemaciclib benefit, WES genomic events including oncogenic and hotspot mutations by OncoKB, and copy number events, of incidence >9% were pre-selected. Results The biomarker subset of monarchE was reflective of the ITT population. A total of 1190 tumors (abemaciclib+ET n= 605; ET alone n=585) yielded adequate RNAseq results. Intrinsic subtype distribution was consistent across tx arms (Table A). Low tumor purity limited assessment of the normal-like subtype. The 4-year IDFS benefit of abemaciclib was consistent across all subtypes. LumA cancers had the lowest risk of recurrence while HER2E and basal-like subtypes had the highest. Inferred 21-gene expression signature score showed similar benefits from abemaciclib in both lower and high-risk groups (Table B). A total of 1173 tumors yielded adequate WES results (abemaciclib+ET n=580; ET alone n=593). Consistent abemaciclib benefit was observed across the most frequently altered genes (Table C). In exploratory analysis, lower benefit from abemaciclib was seen in the subset of focal-high level MYC amplified tumors (n=176, HR 1.30, 95% CI, 0.77, 2.20) compared to MYC non-amplified tumors (n=997, HR 0.62, 95% CI, 0.47, 0.80, nominal interaction p=0.014). The treatment benefit of abemaciclib was observed across all subpopulations of altered genes based on gene expression data. Conclusions Adjuvant abemaciclib+ET maintained IDFS benefit compared to ET alone across all molecular subtypes as measured by RNAseq. Benefit was consistent across most altered genes assessed by WES, except for the subset of tumors with MYC amplification. Additional research is necessary to confirm these findings. Table. Citation Format: Nicholas Turner, Jorge Reis-Filho, Matthew Goetz, Christine Desmedt, Sarat Chandarlapaty, Hironobu Sasano, Carlos Arteaga, Sherene Loi, Stephanie Graff, Deli Liu, Vanessa Rodrik-Outmezguine, Anthony Sireci, Cynthia Sandoval Rubenstein, Helen Won, Lacey M. Litchfield, Maria Munoz, Stephen Johnston. Genomic and transcriptomic profiling of primary tumors from patients with HR+, HER2-, node-positive, high-risk early breast cancer in the monarchE trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS03-06.

Native prey, not landscape change or novel prey, drive cougar (Puma concolor) distribution at a boreal forest range edge.

Many large carnivores, despite widespread habitat alteration, are rebounding in parts of their former ranges after decades of persecution and exploitation. Cougars (Puma concolor) are apex predator with their remaining northern core range constricted to mountain landscapes and areas of western North America; however, cougar populations have recently started rebounding in several locations across North America, including northward in boreal forest landscapes. A camera-trap survey of multiple landscapes across Alberta, Canada, delineated a range edge; within this region, we deployed an array of 47 camera traps in a random stratified design across a landscape spanning a gradient of anthropogenic development relative to the predicted expansion front. We completed multiple hypotheses in an information-theoretic framework to determine if cougar occurrence is best explained by natural land cover features, anthropogenic development features, or competitor and prey activity. We predicted that anthropogenic development features from resource extraction and invading white-tailed deer (Odocoileus virgianius) explain cougar distribution at this boreal range edge. Counter to our predictions, the relative activity of native prey, predominantly snowshoe hare (Lepus americanus), was the best predictor of cougar occurrence at this range edge. Small-bodied prey items are particularly important for female and sub-adult cougars and may support breeding individuals in the northeast boreal forest. Also, counter to our predictions, there was not a strong relationship detected between cougar occurrence and gray wolf (Canis lupus) activity at this range edge. However, further investigation is recommended as the possibility of cougar expansion into areas of the multi-prey boreal system, where wolves have recently been controlled, could have negative consequences for conservation goals in this region (e.g. the recovery of woodland caribou [Rangifer tarandus caribou]). Our study highlights the need to monitor contemporary distributions to inform conservation management objectives as large carnivores recover across North America.

Abstract 4824: Multi-level intervention to increase minority cancer patient enrollment to clinical treatment trials- Study design considerations and baseline characteristics from the ACTWONDER2S Study

Abstract Introduction: Black/African American (AA) and Hispanic cancer patients are underrepresented in cancer clinical trials (CCTs). Disparities stem from multiple factors, thus, comprehensive, multi-level interventions (MLI) are needed. Presented here is a conceptual framework for selecting the appropriate study design for MLIs using ACTWONDER2S, a multi-level intervention (MLI) aimed to increase Black/AA and Hispanic patient participation into CCTs, as an illustrative example. Baseline characteristics of the ACTWONDER2S target populations are also provided. Methods: ACTWONDER2S integrates community health educator and digital tools into an MLI targeting community residents and physicians in the Moffitt Cancer Center (MCC) catchment area, as well as MCC patients, physicians and CCT coordinators. A literature review of the relative strengths and weakness of 5 candidate designs for MLIs was conducted, and a cluster stratified randomized design was selected. Geospatial analytics were used to identify clusters of census tracts (“priority zones”) with high Black/AA and Hispanic populations for intervention deployment. Baseline characteristics of the priority zones were described using US Census data and other sources. Results: 14 priority zones were identified, which were matched on population characteristics and randomized into intervention (n=7) and control (n=7) zones. There were no statistically significant differences between the intervention and control priority zones in total population size (paired t-test p-value=0.63), proportions of Black/AA (p=0.133) and Hispanic populations p=0.17), and distance (in miles) from MCC (p=0.64). Approximately 35.8% and 16.5% of the intervention priority zones were Hispanic or Black/AA, respectively. Average distance to MCC, cancer cases, referral and CCT enrollment rates were also similar between groups. Conclusion: Decision frameworks for MLI study design selection are lacking. The framework provided here for ACTWONDER2S can be applied to other studies seeking to evaluate MLIs. Furthermore, the randomization of the priority zones produced optimal target populations for testing the efficacy of the MIL within ACTWONDER2S. Citation Format: Dana E. Rollison, Rossybelle P. Amorrortu, Lindsay N. Fuzzell, Melany A. Garcia, Elliott S. Tapia-Kwan, Yayi Zhao, Steven A. Eschrich, Bob R. Gore, Brian S. Mittman, Nathanael B. Stanley, Susan T. Vadaparampil. Multi-level intervention to increase minority cancer patient enrollment to clinical treatment trials- Study design considerations and baseline characteristics from the ACTWONDER2S Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4824.

Prevalence and correlates of metabolic syndrome among adults in Freetown, Sierra Leone: A comparative analysis of NCEP ATP III, IDF and harmonized ATP III criteria

BackgroundMetabolic syndrome (MetS) is a global health concern, especially for low and middle-income countries with limited resources and information. The study's objective was to assess the prevalence of MetS in Freetown, Sierra Leone, using the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III), International Diabetes Federation (IDF) and Harmonize ATP III. Additionally, we aimed to establish the concordance between these three different criteria used. MethodsThis community-based health screening survey was conducted from October 2019 to October 2022. A multistage stratified random design was used to select adults aged 20 years and above. Mean, interquartile range (IQR), and logistic regression were used for statistical analysis. The kappa coefficient statistics resolved the agreement between these defined criteria. ResultsThe prevalence for NCEP ATP III, Harmonize ATP III and IDF criteria was 11.8 % (95 % CI: 9.0–15.15), 14.3 % (95 % CI: 11.3–18.0), and 8.5 % (95 % CI: 6.2–11.2), respectively for the 2394 selected adults. The kappa coefficient (κ) agreement between the MetS is: Harmonized ATP III and IDF criteria = [(208 (60.8 %); (κ = 0.62)]; Harmonized ATP III and NCEP ATP III = [(201 (58.7 %); (κ = 0.71)]; while IDF and NCEP ATP III was [(132 (38.6 %); (κ = 0.52)]. In the multivariable regression analysis, waist circumference correlated with all three MetS criteria: ATP III [AOR = 0.85; C.I 95 %: (0.40–1.78), p = 0.032], Harmonized ATP III [AOR = 1.14; C.I 95 %: (0.62–2.11), p = 0.024], IDF [AOR = 1.06; C.I 95 % (0.52–2.16), p = 0.018] ConclusionWe reported a high prevalence of MetS in Freetown, Sierra Leone and identified waist circumference as a major risk factor for MetS. This underscores the crucial role of health education and effective management of MetS in Sierra Leone.

Integrating assemblage structure and habitat mapping data into the design of a multispecies reef fish survey

AbstractObjectiveSince 2010, three spatially disjunct reef fish video surveys have provided fishery‐independent data critical to the assessment and management of reef fishes in the Gulf of Mexico. Although analytical approaches have recently been developed to integrate data from these surveys into a single measure of relative abundance and size composition, a more parsimonious approach would be to integrate survey efforts under a single Gulf‐wide survey design. Accordingly, we conducted a retrospective analysis of historical video‐ and habitat‐mapping data to develop a novel stratified random sampling design for conducting surveys of natural and artificial reef habitats.MethodsWe conducted a series of classification and regression tree analyses to delineate both spatial and habitat strata, and conducted simulations to assess the performance of an optimized survey design.ResultSpatially, classification and regression tree results identified three depth strata (10–25 m, >25–50 m, >50–180 m) and three regional strata (north‐central Gulf, Big Bend, southwest Florida) in the eastern Gulf. For both natural and artificial reefs, habitat strata were delineated based on a combination of relative relief (low, medium, high) and size of the individual reef feature, although reef scale differed markedly between natural (<100 m2, 100–1000 m2, >1000 m2) and artificial habitats (<25 m2, 25–100 m2, >100 m2). To optimize effort among sampling strata, effort was allocated proportionally based on a combination of habitat availability and managed‐species richness for each stratum. Simulation results indicated that relative median biases were <10% and relative median absolute deviations <30% on estimates of abundance for most species examined on natural reefs under the optimal design, except Greater Amberjack Seriola dumerili. These measures of bias and imprecision were similar or higher for most species simulated using simple random and stratified random survey designs. Estimated relative median bias and relative median absolute deviations were notably higher for artificial reef surveys.ConclusionBased on these results, survey efforts were integrated as the Gulf Fishery Independent Survey of Habitat and Ecosystem Resources (G‐FISHER) in 2020.

Effects of uncut grass refuges on the plant community of extensively managed hay meadows

Invertebrates inhabiting grasslands benefit from uncut grass refuges, yet effects on the plant community have not been properly quantified. We experimentally investigated the effects on the vegetation of two different types of refuges. While both consisted in not mowing 10–20% of a meadow area, they differed in their rotation frequency: (1) in within-year rotational refuges (WYRR), the location of the refuge within a meadow was changed at each mowing operation, usually twice a year; (2) in between-years rotational refuges (BYRR), the refuge changed location only between years. A third mowing regime without any refuge was included as control (C) for comparison. The study was conducted in thirty extensively managed meadows across the Swiss lowlands. The vegetation was sampled at two 1-m2 plots within each of the four strata defined by a stratified random design that accounted for the spatial location of the uncut refuge over the years. There were no overall significant negative effects of WYRR on plant species richness and composition at the meadow scale, although a small negative effect was detected locally (i.e. at the refuge scale) where a WYRR had been implemented more than once in the preceding three years. Leaving BYRR negatively impacted plant species richness (-11%), even reducing the number of indicator plant species by 22% (from 4.5 to 3.5 per 2 m2), regardless of when and where refuges were left uncut. A beta-diversity analysis revealed no difference at community level between the two refuge types and control meadows. Previous studies had evidenced positive effects of uncut refuges on herbivore and pollinator communities, while this study shows that the plant community is not affected as long as the location of the refuge is changed at each mowing operation. We thus recommend this measure for promoting biodiversity in extensively managed grasslands.

Evaluating potential changes to the US Chukchi Sea bottom trawl survey design via simulation testing

The US Chukchi Sea consists of the waters off the northwest of Alaska and is a naturally dynamic ice-driven ecosystem. The impacts from climate change are affecting the Arctic marine ecosystem as well as the coastal communities that rely on healthy marine ecosystems. In anticipation of increased ecosystem monitoring in the area, there is an opportunity to evaluate improved sampling designs for future ecological monitoring of the Chukchi Sea, an area that is sampled less comprehensively compared to other regions in Alaska. This analysis focused on standardized NOAA-NMFS-AFSC bottom trawl surveys (otter and beam trawls) and three types of survey designs: simple random, stratified random, and systematic. First, spatiotemporal distributions for 18 representative demersal fish and invertebrate taxa were fitted using standardized catch and effort data. We then simulated spatiotemporal taxon densities to replicate the three survey design types to evaluate design-based estimates of abundance and precision across a range of sampling effort. Modest increases in precision were gained from stratifying the design when compared to a simple random design with either similar or lower uncertainty and bias of the precision estimates. There were often strong tradeoffs between the precision and bias of the systematic estimates of abundance (and associated variance) across species and gear type. The stratified random design provided the most consistent, reliable, and precise estimates of abundance indices and is likely to be the most robust to changes in the survey design. This analysis provides a template for changing bottom trawl survey designs in the Chukchi Sea and potentially other survey regions in Alaska going forward and will be important when integrating new survey objectives that are more ecosystem-focused.

Credit Accessibility and Performance of Small and Medium Enterprises in Meru County, Kenya

This study sought to investigate the credit accessibility and performance of SMEs in Meru County, Kenya. Specifically, the study sought to determine the influence of lending procedures on the performance of SMEs in Meru County. The study adopted a descriptive research design. The targeted population comprised 599 SMEs registered by the Meru County Government, which were operating in the previous three years, and then within the nine sub-counties of Meru County. The researcher used Krejcie and Morgan's table to determine sample size from a given population to determine a sample of 234 SMEs and proportionate random stratified design to identify the SMEs to comprise the sample. Questionnaires were used to collect data from respondents, with each SME being represented by the owner or a senior employee. Data were analyzed and presented using descriptive statistics like frequency tables and graphs. Chi-square tests were conducted to test for any relationship between independent variables and the performance of SMEs in the county. The study revealed that the majority of the respondents (83%) agreed that the loan application process was complicated. It was revealed that the lending procedure had a statistically significant relationship with the performance of SMEs in Meru County. The study recommends that financial institutions should simplify the loan application process as much as possible.

Atmospheric pollution by potentially toxic elements: measurement and risk assessment using lichen transplants

ABSTRACT The lichen Usnea articulata collected from an unpolluted area was exposed for 6 months at 26 sites for the sample chosenusing a stratified random design, and the content of potentially toxic elements (PTEs) including As, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sn, V, and Zn, was assessed using ICP-MS. The health risk for both adults and children was then calculated using the PTEs concentrations. The results showed that despite the hostile urban conditions, transplanted lichens depicted clear deposition patterns of airborne PTEs, mostly associated with industrial sites, where As and other elements showed remarkably high values. The cumulative hazard index was below the risk threshold, both for adults and children. For the entire population (particularly children) residing in areas surrounding industrial sites, As and Cr appeared to be potentially carcinogenic elements.

Mode of Communication and Employee Engagement in Technical Training Institutions in Kenya

Purpose: This study sought to determine the effect of the communication mode on employee engagement in technical training institutions in Kenya.
 Methodology: The study was conducted using survey research design. Study population was all the 3780 trainers in the 102 public technical training institutions in Kenya out of which a sample of 360 respondents was used. Stratified random sampling, random sampling and stratified proportionate random sampling technique design were employed. Data was collected using a questionnaire which had both closed and open- ended (Likert type scale 1-5) questions. Questionnaires were distributed to 360 respondents out of which 322 completed the questionnaires giving a response rate of 89.4%. Cronbach’s alpha was used to test for internal reliability of each variable used in the study. Data analysis was done by use of descriptive and inferential statistics.
 Findings: Logistic regression coefficients showed that communication mode influenced employee engagement and in a negative way. The effect therefore, was not statistically significant (β=-0.647, p=0.114). This implies that communication mode is not a significant predictor of employee engagement in technical training institutions in Kenya.
 Recommendations: The study recommends that technical training institutions should endeavor to embrace modern methods of communication. In an increased switch on world, the staff and the students rely on technology as their primary means of communication. Computers, smart phones and tablet devices are ubiquitous. It is imperative for technical training institutions to stop over relying on traditional methods such as notice boards, meetings and paper based newsletters like in the past years.

Quality of Messages on Employee Engagement in Technical Training Institutions in Kenya

Purpose: The purpose of this research was to establish the effect of quality of messages on employee engagement in technical training institutions in Kenya. 
 Methodology: The study was conducted using survey research design. Study population was all the 3780 trainers in the 102 technical institutions in Kenya out of which a sample of 360 respondents was used. Stratified random sampling, random sampling and stratified proportionate random sampling technique design were employed. Data was collected using a questionnaire which had both closed-ended (Likert type scale 1-5) questions and open ended questions. Questionnaires were distributed to 360 respondents out of which 322 completed the questionnaires giving a response rate of 89.4%. Cronbach’s alpha was used to test for internal reliability of each variable used in the study. Data analysis was done by use of descriptive and inferential statistics.
 Findings: The findings of the study supported that quality of messages has a significant effect on employee engagement and hence, it is a predictor of employee engagement among the trainers of technical institutions in Kenya.
 Recommendation: This study recommends that there is need to improve the quality of messages as it significantly affects employee engagement in technical training institutions in Kenya. This can be done by ensuring that the messages are timely, accurate, adequate and complete.

Determining the role of land resource, cropping and management practices in soil organic carbon status of rice-based cropping systems

Rice-based cropping systems (RBCS) cover the majority of cultivated land in Bangladesh and are the country's primary source of food security. To bolster food security, cropping intensity has increased by 192% in the last 30 years. Concerns have been raised about the sustainability of such cropping increases, particularly for soil productivity and resilience, with many areas reporting low soil organic carbon (SOC). The research assessed the levels of SOC, total nitrogen (TN) and soil pH in RBCS to identify relative importance of the land resource, cropping and management settings on these soil properties and to determine options for sustainable land use intensification. Soil samples (0–30 cm) were collected following stratified random design from a range of RBCS and analyzed for SOC, TN and soil pH. These soil properties were interpreted against previously developed farming system typology of Soil Carbon Improvement Likelihood (SCIL) and the legacy soil datasets. SOC was recorded higher in the stop-go triple cropping (12.00–16.33 g/kg) compared to the triple and double cropping intensities (6.90–8.30 g/kg). The crop-diversified and mustard-rice cropping systems of High SCIL, where there is crop rotational diversity and high residue retention, recorded a higher SOC. However these systems were also located on inherently fertile soil (Floodplain medium highland) compared to the less diverse cropping systems (wheat-rice, veg.-rice and rice-rice) of Medium and Low SCIL. The wheat-rice system had the lowest SOC (5.46 g/kg), which is considered to be a consequence of low crop residue retention and reduced periods of inundation in highland on the Piedmont plain or Terrace. However, the build up of SOC and TN was linked to soil acidification associated with altered fertilizer regime and crop residue removal. Cropping intensity, and in particular, the associated cropping systems and management, were determinants of SOC, depending on which land resource setting and cropping systems were practiced by the smallholders. The types of cropping systems and management options in land resource settings were identified that have the potential for sustainable land use intensification. The implications would be to ensure these cropping systems are conserved, and trade offs contemplated to meet the rising food demand and carbon sequestration goals to counteract smallholder vulnerability to climate change in Bangladesh and South Asian countries.

Energy and monetary efficiencies at the different altitudinal agroecosystems in central Himalaya, India

Himalayas with diverse topographical and ecological zones sustain diverse agroecosystems. Differences in precipitation regimes, cropping systems, land-use systems and availability of resources significantly affect energy flow within agroecosystems (AGEs) of the region. Thus, the present study was aimed to evaluate the energy use pattern and economic profitability of different sized agroecosystems (small, medium and large) along the altitudinal gradient [very low altitude (VLA), low altitude (LA), mid altitude (MA) and high altitude (HA)] of Central Himalaya, India. The sampling was carried out following random stratified design and total 108 agroecosystems (4 altitudes× 3 sizes × 3 replicates × 3 seasons) were assessed. Data collected on quantities of agricultural inputs and outputs were converted to energy values using standard energetic constants and monetary values on the basis of local market price. Low altitude agroecosystems predominantly support cereal + pulse based cropping systems while, high altitudes favour cash crop cultivation (vegetables). Significant variation (P < 0.05) in total input and output energy was observed seasonally, while differences were insignificant across sizes and altitudes. Irrespective of the sizes and seasons, farmyard manure (organic fertilizer) contributed major share of total energy inputs across all altitudes in the order: HA AGEs (66.7 %) > MA AGEs (66.1 %) > VLA AGEs (62.6 %) > LA AGEs (52.1 %). The share of non-renewable energy inputs (inorganic fertilizers and fuel) declined along altitudinal gradient as: LA (31.1 %) > VLA (26.9 %) > MA (12.5 %) > HA (11.8 %). Seasonally, highest net energy was recorded during rainy season (92286 M J ha−1 yr−1) followed by summer (68906 M J ha−1 yr−1) and winter (18686 M J ha−1 yr−1). The economic yield significantly increased with increasing altitude and was recorded maximum for large sized agroecosystems. Energy use efficiency (EUE) differed distinctly (P < 0.05) across seasons and was recorded maximum during rainy season (8) while, across sizes and altitudes it did not vary significantly. EUE did not reflect any definite pattern along altitudinal gradient [HA AGEs (3.84) > VLA AGEs (3.81) > LA AGEs (3.56) > MA AGEs (3.01)]. Benefit-cost ratios (BCR) differed significantly (P < 0.05) along altitudes and was maximum at VLA AGEs (5.27) however, differences were insignificant across sizes and seasons. From present study, it can be concluded that season and altitude had significant impact on the energetics and economic flow of the agroecosystems while, no marked differences were observed for size classes. High altitude agroecosystems were energetically efficient while, monetary wise very low altitude systems.

Natural Regeneration; 4 Years after the Ekiugbo Oil Spill, at Ughelli, Delta State, Nigeria: Implication for Phytoremediation Potential

This study assessed the floristic composition, structural classification and phytosociology of life form regeneration, mode of regeneration and demographic status of regeneration in vegetation forest, 4 years after pollution impact. It was aimed at evaluating the phytoremediation potential of some hydrocarbon tolerant macrophytes (HTM). Conventional ecological approach involving stratified simple random design method and phytosociological indices were used. Result has classified the study site flora as low land secondary mosaic vegetation with heterogenous continuum in spatial and closed horizontal structural arrangement. Phytosociological dynamics of 51 herbaceous and 12 shrubby life forms of 63 representative species under 21 families and 49 genera of angiosperms recorded changes. Four prevalently dominant families very abundant with highest species diversity richness and three families in abundance were recorded. Shrubby recruit was lower than Herbaceous recruits with the Herbaceous sedge (HS) recording highest recruits among regenerating life forms (HS&gt;HG&gt;HH&gt;HCl). The herbaceous life form had Chamaephytes 33(64.71%) and Hemicryptophytes 18(35.29%). The shrubby life form recorded 2(11.11%) Nanophanerophytes and Mesophanerophytes respectively and 8(66.67%) Microphanerophytes. The herbaceous life form mode of regeneration had 28 recruits with multiplier mode, and 23 recruits with single mode of regeneration. Four recruits exhibited multiplier mode and eight with single mode of regeneration across shrubby life form. Demographic status of regeneration revealed greater seedling than sapling density devoid of adult tree recruits, thus implies “successful and new regeneration” Keywords: Coppice, Recruits, Rhizome, Sapling, and Seedlings. DOI: 10.7176/JEES/12-11-04 Publication date: November 30 th 2022

Cross-scale regulation of seasonal microclimate by vegetation and snow in the Arctic tundra.

Climate warming is inducing widespread vegetation changes in Arctic tundra ecosystems, with the potential to alter carbon and nutrient dynamics between vegetation and soils. Yet, we lack a detailed understanding of how variation in vegetation and topography influences fine-scale temperatures ("microclimate") that mediate these dynamics, and at what resolution vegetation needs to be sampled to capture these effects. We monitored microclimate at 90 plots across a tundra landscape in western Greenland. Our stratified random study design covered gradients of topography and vegetation, while nested plots (0.8-100 m2 ) enabled comparison across different sampling resolutions. We used Bayesian mixed-effect models to quantify the direct influence of plot-level topography, moisture and vegetation on soil, near-surface and canopy-level temperatures (-6, 2, and 15 cm). During the growing season, colder soils were predicted by shrub cover (-0.24°C per 10% increase), bryophyte cover (-0.35°C per 10% increase), and vegetation height (-0.17°C per 1cm increase). The same three factors also predicted the magnitude of differences between soil and above-ground temperatures, indicating warmer soils at low cover/height, but colder soils under closed/taller canopies. These findings were consistent across plot sizes, suggesting that spatial predictions of microclimate may be possible at the operational scales of satellite products. During winter, snow cover (+0.75°C per 10 snow-covered days) was the key predictor of soil microclimate. Topography and moisture explained little variation in the measured temperatures. Our results not only underline the close connection of vegetation and snow with microclimate in the Arctic tundra but also point to the need for more studies disentangling their complex interplay across tundra environments and seasons. Future shifts in vegetation cover and height will likely mediate the impact of atmospheric warming on the tundra soil environment, with potential implications for below-ground organisms and ecosystem functioning.

Assessing the Suitability of Habitats for Porphyrio porphyrio indicus and Amaurornis phoenicurus in Urban Wetlands of Peninsular Malaysia

It becomes imperative to understand the eco-climatic predictors and know the suitable habitat for Porphyrio porphyrio indicus and Amaurornis phoenicurus in the urban wetlands to prevent their local extinction. The study explored the habitat suitability for Porphyrio porphyrio indicus and Amaurornis phoenicurus in Paya Indah wetlands and Putrajaya wetlands of Peninsular Malaysia. Porphyrio porphyrio indicus and Amaurornis phoenicurus surveyed using the point count technique, and a stratified random design. The maximum entropy modelling (MEM) approach and geographic information systems employed to determine the influence of 17 eco-climatic factors on the suitable habitats for the species. Water at a minimum depth (44.30%) and rainfall (74.20%) contributed to the availability of suitable habitats for Porphyrio porphyrio indicus in Paya Indah and Putrajaya wetlands. Also, dissolved oxygen (56.60%) and salinity (43.50%) contributed to habitat suitability for Amaurornis phoenicurus in Paya Indah and Putrajaya wetlands. Large portions of the two urban wetlands were unsuitable for the Porphyrio porphyrio indicus and Amaurornis phoenicurus populations because of several eco-climatic factors. Thus, the models as management tools with a robust population monitoring database and framework would enhance the management effectiveness of the two species and urban wetlands.

A comparison of monitoring designs to assess wildlife community parameters across spatial scales.

Dedicated long-term monitoring at appropriate spatial and temporal scales is necessary to understand biodiversity losses and develop effective conservation plans. Wildlife monitoring is often achieved by obtaining data at a combination of spatial scales, ranging from local to broad, to understand the status, trends, and drivers of individual species or whole communities and their dynamics. However, limited resources for monitoring necessitates tradeoffs in the scope and scale of data collection. Careful consideration of the spatial and temporal allocation of finite sampling effort is crucial for monitoring programs that span multiple spatial scales. Here we evaluate the ability of five monitoring designs-stratified random, weighted effort, indicator unit, rotating panel, and split panel-to recover parameter values that describe the status (occupancy), trends (change in occupancy), and drivers (spatially varying covariate and an autologistic term) of wildlife communities at two spatial scales. Using an amphibian monitoring program that spans a network of US national parks as a motivating example, we conducted a simulation study for a regional community occupancy sampling program to compare the monitoring designs across varying levels of sampling effort (ranging from 10% to 50%). We found that the stratified random design outperformed the other designs for most parameters of interest at both scales and was thus generally preferable in balancing the estimation of status, trends, and drivers across scales. However, we found that other designs had improved performance in specific situations. For example, the rotating panel design performed best at estimating spatial drivers at a regional level. Thus, our results highlight the nuanced scenarios in which various design strategies may be preferred and offer guidance as to how managers can balance common tradeoffs in large-scale and long-term monitoring programs in terms of the specific knowledge gained. Monitoring designs that improve accuracy in parameter estimates are needed to guide conservation policy and management decisions in the face of broad-scale environmental challenges, but the preferred design is sensitive to the specific objectives of a monitoring program.

Generating unbiased estimates of burrowing seabird populations

Maximising survey efficiency can help reduce the tradeoff between spending limited conservation resources on identifying population changes and responding to those changes through management. Burrow‐nesting seabirds are particularly challenging to survey because nests cannot be counted directly. We evaluated a stratified random survey design for generating unbiased population estimates simultaneously for four petrel species nesting on Macquarie Island, Australia, where the survey cue, burrow entrances, is similar for all species. We also compared the use of design‐based and model‐based analyses for minimising uncertainty in estimates. We recorded 2845 Antarctic prion burrows, 306 white‐headed petrel burrows and two blue petrel burrows while distance‐sampling along 154 km of transects. For blue petrels and grey petrels, we completed nocturnal searches along a further 71 km and searched 249 km of tracks during follow‐up ground searches. We failed to generate unbiased population estimates for two rare and localised species, blue and grey petrels, from our stratified random survey. Only for the most widespread and abundant species, Antarctic prion, did the estimate have reasonable power to detect a rapid population change. Model‐based analyses of the stratified random survey data did not improve upon traditional design‐based analyses in terms of uncertainty in population estimates, but they did provide useful spatial representation of current populations. Models that used the targeted survey data did not reflect current population sizes and distributions of the two rare and localised species. We found that when species ecologies, distributions and abundances vary, a multi‐method approach to surveys is needed. Species with low abundance that occur patchily across large islands are likely to be best estimated using targeted surveys, whereas widespread and abundant species can be accurately and precisely estimated from randomised surveys using informative model‐based analyses.

Species‐level CWM values mask contrasting intra‐ versus interspecific trait shifts at subtropical forest edges

Altered microclimatic conditions and higher disturbance at forest edges create environmental stress and modify resource gradients from edge to interior, changing the selection pressures acting on individuals. Although community‐weighted trait‐mean (CWM) shifts along edge gradients have been widely documented at the species level, it is unclear how edge effects act at the individual level, and whether the direction of intraspecific trait shifts mirrors that of CWM shifts in response to edge effects. On 20 islands in the Thousand Island Lake, China, we established 484 plots (2 × 2 m) in a stratified random design across distances of 0–128 m from the forest edge. Within each plot, we sampled leaves (n = 34 768) from within and among all 2993 individuals of 68 species and measured five leaf traits (leaf area, LA; specific leaf area, SLA; leaf dry matter content, LDMC; thickness, LT; chlorophyll content, LCC). Using generalized linear mixed models, we found that different leaf traits exhibited contrasting shifts in inter‐ versus intraspecific trait variation in response to edge effects. For SLA, LT and LCC, negative covariance between inter‐ and intraspecific trait shifts resulted in dampening of community‐wide trends compared to CWM response to edge effects. In contrast, the community‐wide trend for LDMC was reinforced due to positive covariance between inter‐ and intraspecific trait shifts, while for LA the direction of covariance shifted from negative to positive on small versus large islands. Together, edge effects alter selection regimes in reassembling plant communities. Predicting the community‐wide consequences depends on the degree to which there is negative versus positive covariance between species sorting and within‐species adaptation. The widely‐used CWM approach can mask contrasting trait selection pressures acting on individuals within local populations. Individual‐level trait variation can improve understanding of community re‐assembly trajectories in response to global environmental change.

Relationship between the distribution of vegetation and the environment in the coastal embryo dunes of Jalisco, México.

BackgroundThe poorly developed soils of the embryo dunes imply little capacity for plant support, however, the adaptation mechanisms of plants respond sensitively to environmental variations, even when these variations are small, which results in a set of specialized habitats and flora that are rarely shared with other terrestrial ecosystems. The coastal dunes of the Mexican Pacific remain vaguely studied, this is why this research explored the relationship between environmental properties and the presence of plant species in the embryo dunes of the coast of Jalisco, Mexico.MethodsTwenty-nine sites were sampled, one or two sites per embryo dune, with a random stratified design. Geomorphological and vegetation data were collected at site. Laboratory determinations included soil color, particle size, organic matter, pH, electrical conductivity, magnetite content, and moisture retention. Statistical analysis included correlation analysis to identify relationships between environmental variables; principal component analysis (PCA) and cluster analysis to group dune sites by environmental properties; canonical correspondence analysis (CCA) to determine a possible significant relationship between the presence of plant species and environmental variables; cluster analysis to group dune sites by presence/absence of plant species and correlate both clusters to validate the relationship between them, the salient aspects of this relationship were described and the spatial distribution of the groups was mapped.ResultsEleven plant species were identified, six of them exclusive to the embryo dunes and the rest ubiquitous. The incipient development of these soils is reflected in a low content of organic matter, silt, clay, and moisture retention, with scattered data on granulometry, electrical conductivity, organic matter, and magnetite. Some significant correlations were found between some environmental properties, and the CCA showed a significant relationship between the presence of plant species and environmental variables (p-value of the Monte Carlo test = 0.026). The cluster analysis of dune sites according to environmental variables and the cluster analysis by presence/absence of plant species produces the formation of five groups of sites with significant environmental differences and five groups of sites with significant floristic differences. A significant connection (r = 0.471, p = 0.01) between the two clustering schemes also evidences the meaningful relationship between the presence of plant species and the environmental characteristics of the embryo dunes of Jalisco, Mexico. Differences in habitat preferences were observed among plant species exclusive to the embryo dunes; thus, Abronia maritima, Uniola pittieri, and Pectis arenaria showed a preference for embryo dunes with poor edaphic conditions, in contrast to Okenia hypogaea, Canavalia rosea, and Scaevola plumieri, which were mostly found in embryo dunes with higher fertility.