Small Habitat Research Articles

Using sUAV imagery to map litter of invasive annual grass in dry environmental conditions

Invasive annual grasses pose a severe threat to drylands of the United States by increasing habitat degradation and the occurrence and severity of wildfires, while simultaneously outcompeting native species. Advances in technology and accessibility of small uncrewed aerial vehicles (sUAV) provide the opportunity for small preserve managers to map and monitor plant invasions in critical habitats for rare and endemic plant species. Many remote sensing techniques rely on the invasive plants' different phenological signals to distinguish them from native plants and habitats. However, invasive annual grasses in the western United States have high variability of interannual productivity and may not green up each year. Therefore, our objective was to use an sUAV (quadcopter drone) to map invasive annual grass regardless of phenological stage in critical Mojave Desert habitat. The study locations were White Dome, a small habitat preserve, and Beehive Dome in Washington County UT, USA. These areas are critical habitats for several endangered and threatened plant species and are covered with sensitive biological soil crusts, making on-the-ground measurements destructive. Using imagery collected with an sUAV we created red, green, blue (RGB) orthomosaics and calculated the Visible Atmospherically Resistant Index (VARI) across these areas. We successfully mapped the litter of invasive annual grasses at one of the two sites. At White Dome, we attained 95.2 % and 84.3 % Producer's and User's Accuracy in mapping invasive annual grasses based on the RGB spectral signature of invasive grass litter. At Beehive Dome, the heterogeneous nature of the edaphic and topographical features made it difficult to accurately map (<20 %) using VARI and RGB alone. Here, we propose plans to increase accuracy in these dryland systems to be able to map invasive annual grasses regardless of year or environmental conditions.

Contrasting responses of vascular plants and bryophytes to present and past connectivity in unmanaged grasslands

The area of semi-natural grasslands has decreased dramatically causing many grassland specialist species to persist in small habitat fragments. Furthermore, ecological communities once shaped by disturbances related to traditional agriculture now face the impacts of modern agriculture and urbanization. Many of the species have become endangered due to the combined effects of habitat destruction and degradation. We studied the responses of vascular plants and bryophytes to present and past connectivity in semi-natural grasslands, while accounting for the effects of local environmental conditions. We conducted vegetation surveys in 33 fragmented, unmanaged dry grasslands in Southwest Finland. A total of 191 vascular plant species and 60 bryophyte species were recorded. Higher vascular plant diversity was associated with higher historical connectivity, whereas bryophyte diversity declined with increasing current connectivity. Edaphic conditions, microclimate and disturbances were found to structure both vascular plant and bryophyte communities, but the responses to individual environmental variables were very different. The contrasting responses could be explained by the differences between the typical life-history strategies in vascular plants and bryophytes as well as resource competition between the two groups. These results highlight the need to consider different species groups when planning conservation measures. Vascular plant richness may best be conserved in connected grasslands whereas bryophyte richness in isolated ones. The results also indicated that trampling by humans could result in positive disturbance and to some extent help maintain richness of grassland specialist species.

A little does a lot: Can small-scale planting for pollinators make a difference?

Insect pollinators are declining globally as a result of the anthropogenic pressures that have destroyed native habitats and eroded ecosystems. These declines have been associated with agricultural productivity losses, threatening food security. Efforts to restore habitat for pollinators are underway, emphasizing large-scale habitat creation like wildflower strips, yet ignoring the impact of smaller or more isolated patch-creation.A meta-analysis of 31 independent published studies assessed the effect of scale of pollinator planting interventions (herbaceous strips, hedgerows, fertiliser/grazing/mowing control). We assessed pollinator species richness and abundance against size of intervention and type. Pollinator conservation interventions increased species richness and abundance in almost all of the studies examined, with the greatest increases in pollinator ecological metrics seen from hedgerows covering 40 m² and herbaceous interventions at 500 m².We then analysed results from a 5-year study that deployed small pollinator habitats (30 m²) at community gardens and farms (<150,000 m²) practicing organic methods in the Pacific Northwest US. Small additions to pollinator resources had a significant local impact on pollinator abundance, but this effect was lost when these relatively small additions were introduced to sites in larger landscapes (>150,000 m²).Together, we show that small interventions (∼500 m²) can significantly benefit pollinators, but only when sufficiently densely distributed at a landscape level. Though we understand the effects of single interventions at various scales, future research is needed to understand how these relatively small interventions act cumulatively at a landscape scale, and within this context whether larger areas are still needed for some species. Nonetheless, these preliminary data are promising, and may play an important role in convincing smaller landowners to act to preserve insect pollinators.

Importance of grassy and forest non-crop habitat islands for overwintering of ground-dwelling arthropods in agricultural landscapes: A multi-taxa approach

Non-crop habitats are supposed to provide valuable resources to beneficial arthropods inhabiting agricultural landscapes during both the growing and winter seasons. Unfortunately, studies focused on the performance of non-crop habitats during the winter period are much less abundant, despite their importance for efficient biodiversity conservation measures. In this study, we assessed the distribution of ground-dwelling arthropods overwintering on arable land as well as the boundaries and interiors of neighbouring grassy and forest non-crop habitat islands. Myriapods, spiders, carabid and rove beetles were collected using a combination of quadrat sampling (soil sampling) and pitfall trapping. Our results revealed the importance of both non-crop habitat islands for overwintering arthropods, though slightly higher abundance and species richness were recorded in forest compared to grassy islands. Abundance and species richness of overwintering arthropods were lower on arable land for all the investigated taxa. Carabid and rove beetles overwintered more on non-crop boundaries than interiors, whereas spiders and myriapods used both boundaries and interiors. Landscape composition had stronger effects on carabids and myriapods collected with pitfall traps, which were benefitted in landscapes with high non-crop habitat cover. Grassy and forest non-crop habitat islands hosted different assemblages of myriapods, carabids and rove beetles, highlighting the complementarity of both non-crop habitat types for ground-dwelling arthropods. We recommend to preserve all existing non-crop habitat patches and to create new permanent non-crop habitat patches in intensively managed agricultural landscapes, as even relatively small non-crop habitat islands within the cultivated land can play a relevant role for overwintering arthropods.

The impacts of water level fluctuations from paddy fields and aquaculture ponds on wetland habitats for wintering waterbirds: Implications for wetland management

The distribution and composition of wetland habitats for wintering waterbirds are heavily influenced by water level fluctuations. Through polder construction and aquaculture activities, paddy fields and aquaculture ponds have decreased the lateral connectivity of water level fluctuations in the lake. However, the impacts of water level fluctuations on habitat suitability, which can be seen using high-resolution images analysis, often cannot separate disturbances caused by the paddy fields and aquaculture ponds, and it is difficult to capture the actual impact of water level fluctuations on wetland habitats. Based on remote sensing image data and hydrological data, we selected Caizi Lake as a study site and comparatively analyzed the changes in wintering waterbird habitats in a water level sequence under the two scenarios. Our work showed that paddy fields and aquaculture ponds should be considered as potential options for creating more suitable habitats for migratory waterbirds if combined with reasonable and effective management of the water level within the paddy fields and aquaculture ponds. The present study results could facilitate the management and sustainable utilization of Caizi Lake wetlands and provide support for creating small habitats by managing the water levels of paddy fields and aquaculture ponds.

Loss of the world's smallest forests.

A large number of small forests typically harbor higher biodiversity than a small number of large forests totaling the same area, suggesting that small patches are disproportionately valuable for biodiversity conservation. However, policies often favor protection of large forest patches. Here we demonstrate a global trend of higher deforestation in small than large forest patches: the likelihood that a randomly selected forest plot disappeared between 1992 and 2020 increased with decreasing size of the forest patch containing that plot. Our results imply a disproportionate impact of forest loss on biodiversity relative to the total forest area removed. Achieving recent commitments of the post-2020 Global Biodiversity Framework will require revision of current policies and increased societal awareness of the importance of small habitat patches for biodiversity protection.

Very small collars: an evaluation of telemetry location estimators for small mammals

BackgroundFine-scale tracking of animals such as Peromyscus spp. is still done with micro-very high frequency collars due to the animal’s small size and habitat usage. In most cases, tracking micro-very high frequency collars requires manual telemetry, yet throughout the literature, there is little reporting of individual telemetry methods or error reporting for small mammal spatial analyses. Unfortunately, there is even less documentation and consensus on the best programs used to calculate fine-scale animal locations from compass azimuths. In this study, we present a strategy for collecting fine-scale spatial data on Peromyscus spp. as a model species for micro-very high frequency collars and assess multiple programmatic options and issues when calculating telemetry locations.ResultsMice were trapped from April to October 2018–2019 with Sherman traps in Howard County, Maryland, USA. Collars were placed on 61 mice, of which 31 were included in the analyses. We compared the two most cited location estimator programs in the literature, location of a signal software and Locate III, as well as the Sigloc package in program R. To assess the programmatic estimates of coordinates at a fine scale and examine programmatic impacts on different analyses, we created and compared minimum convex polygon and kernel density estimator home ranges from locations produced by each program. We found that 95% minimum convex polygon home range size significantly differed across all programs. However, we found more similarities in estimates across calculations of core home ranges. Kernel density estimator home ranges had similar patterns as the minimum convex polygon home ranges with significant differences in home range size for 95% and 50% contours. These differences likely resulted from different inclusion requirements of bearings for each program.ConclusionsThis study highlights how different location estimator programs could change the results of a small mammal study and emphasizes the need to calculate telemetry error and meticulously document the specific inputs and settings of the location estimator.

A Study of Intelligent Paper Grouping Model for Adult Higher Education Based on Random Matrix

This paper presents a comprehensive study and analysis of the intelligent grouping of papers in adult higher education using a random matrix approach. Using the results of random matrix theory on the eigenvalues of the sample covariance matrix, the energy of each subspace is estimated, and the estimated energy is then used to construct a subspace weighting matrix. The statistical properties of the sample covariance matrix eigenvectors are analyzed using the first-order perturbation approximation, and then, asymptotic results from random matrix theory on the projection of the sample covariance matrix signal subspace to the real signal parametrization are used to obtain the weighting matrix based on the random matrix eigenvectors. Dynamic adjustment according to the fitness of individuals in the population is performed to ensure population diversity, while the combination of the small habitat technique can avoid the algorithm from falling into early convergence. The algorithm introduces chaos theory to optimize the population initialization process and uses the dynamic traversal randomness of chaos to select individuals in the population so that the initial population is close to the desired target solution. The design of the fitness function in the genetic algorithm generally maps the objective function of the problem to the fitness function. A good fitness function can directly reflect the quality of the individuals in the group. Based on the in-depth study of the basic attributes of the test questions and the principles of test paper evaluation, the mathematical model and objective function of intelligent paper grouping are determined by the difficulty, knowledge points, and cognitive level of the test questions as the main constraints, and NCAGA is applied to the intelligent paper grouping method, which better completes the intelligent paper grouping session for the computer system architecture course. In the process of designing the intelligent grouping algorithm, for the situations of premature convergence and convergence to locally optimal solutions that easily occur in the traditional genetic algorithm, this paper adopts the approach of adaptive adjustment of crossover probability and variation probability to improve the algorithm and achieves satisfactory results. Based on extensive business research, this paper completes the requirement analysis of the online practice system based on the intelligent grouping of papers and presents the functional design and database design of the key functional modules in the system in detail. Finally, this paper conducts functional tests on the system and analyses the test results.

Molecular Analysis and Phylogenetic Relationship of Filamentous Green Algae - Pithophora roettleri (Roth) Wittrock

Algae were considered to be the first species that appeared billions of years before plants, which are capable of photosynthesis. Filamentous green algae are characteristic of littoral algal communities which are found to be attached to the substrate or floating aggregations in the freshwater habitats. In small water habitats, these green algae are very common and almost occur everywhere. Most of the algae serve as food for aquatic animals and are also used to manufacture papers and fibres. Hence it possesses good economic value. Pithophora is a species found throughout the world, mainly in tropical and temperate regions. This study aims to authenticate the algae by means of morphological and molecular characterization. The molecular characterization was carried out using partial sequencing of 28S rRNA. The data were interpreted with the BLAST program in the NCBI database, where the sequence of algae revealed the identity matches in the range of 99.59% with the available Pithophora roettleri (MN017042.1) strain recovered from the GenBank.

Single large AND several small habitat patches: A community perspective on their importance for biodiversity

The debate whether single large or several small (SLOSS) patches benefit biodiversity has existed for decades, but recent literature provides increasing evidence for the importance of small habitats. Possible beneficial mechanisms include reduced presence of predators and competitors in small habitat areas or specific functions such as stepping stones for dispersal. Given the increasing amount of studies highlighting individual behavioral differences that may influence these functions, we hypothesize that the advantage of small versus large habitat patches not only depends on patch functionality but also on the presence of animal personalities (i.e., risk-tolerant vs. risk-averse). Using an individual-based, spatially-explicit community model, we analyzed the diversity of mammal communities in landscapes consisting of a few large habitat islands interspersed with different amounts and sizes of small habitat patches. Within these heterogeneous environments, individuals compete for resources and form home-ranges, with only risk-tolerant individuals using habitat edges. Results show that when risk-tolerant individuals exist, small patches increase species diversity. A strong peak occurs at approximately 20% habitat cover in small patches when those small habitats are only used for foraging but not for breeding and home-range core position. Additional usage as stepping stones for juvenile dispersal further increases species persistence. Overall, our results reveal that a combination of a few large and several small habitat patches promotes biodiversity by enhancing landscape heterogeneity. Here, heterogeneity is created by pronounced differences in habitat functionality, increasing edge density, and variability in habitat use by different behavioral types. The finding that a combination of single large AND several small (SLASS) patches is needed for effective biodiversity preservation has implications for advancing landscape conservation. Particularly in structurally poor agricultural areas, modern technology enables precise management with the opportunity to create small foraging habitats by excluding less profitable agricultural land from cultivation.

Species accumulation in small–large vs large–small order: more species but not all species?

Although groups of small habitat patches often support more species than large patches of equal total area, their biodiversity value remains controversial. An important line of evidence in this debate compares species accumulation curves, where patches are ordered from small–large and large–small (aka ‘SLOSS analysis’). However, this method counts species equally and is unable to distinguish patch size dependence in species’ occupancies. Moreover, because of the species–area relationship, richness differences typically only contribute to accumulation in small–large order, maximizing the probability of adding species in this direction. Using a null model to control for this, I tested 202 published datasets from archipelagos, habitat islands and fragments for patch size dependence in species accumulation and compared conclusions regarding relative species accumulation with SLOSS analysis. Relative to null model expectations, species accumulation was on average 2.7% higher in large–small than small–large order. The effect was strongest in archipelagos (5%), intermediate for fragments (1.5%) and smallest for habitat islands (1.1%). There was no difference in effect size among taxonomic groups, but each shared this same trend. Results suggest most meta-communities include species that either prefer, or depend upon, larger habitat patches. Relative to SLOSS analysis, null models found lower frequency of greater small-patch importance for species representation (e.g., for fragments: 69 vs 16% respectively) and increased frequency for large patches (fragments: 3 vs 25%). I suggest SLOSS analysis provides unreliable inference on species accumulation and the outcome largely depends on island species–area relationships, not the relative diversity value of small vs large patches.

Natural and anthropogenic landscape factors shape functional connectivity of an ecological specialist in urban Southern California.

Identifying how natural (i.e., unaltered by human activity) and anthropogenic landscape variables influence contemporary functional connectivity in terrestrial organisms can elucidate the genetic consequences of environmental change. We examine population genetic structure and functional connectivity among populations of a declining species, the Blainville's horned lizard (Phrynosoma blainvillii), in the urbanized landscape of the Greater Los Angeles Area in Southern California, USA. Using single nucleotide polymorphism data, we assessed genetic structure among populations occurring at the interface of two abutting evolutionary lineages, and at a fine scale among habitat fragments within the heavily urbanized area. Based on the ecology of P. blainvillii, we predicted which environmental variables influence population structure and gene flow and used gravity models to distinguish among hypotheses to best explain population connectivity. Our results show evidence of admixture between two evolutionary lineages and strong population genetic structure across small habitat fragments. We also show that topography, microclimate, and soil and vegetation types are important predictors of functional connectivity, and that anthropogenic disturbance, including recent fire history and urban development, are key factors impacting contemporary population dynamics. Examining how natural and anthropogenic sources of landscape variation affect contemporary population genetics is critical to understanding how to best manage sensitive species in a rapidly changing landscape.

Biodiversity significance of small habitat patches: More than half of Indian bird species are in academic campuses

Habitat loss, fragmentation, and land-use changes threaten global biodiversity, and human needs are increasingly compromising the functional role of protected areas. Therefore, finding opportunities to conserve biodiversity within the human-modified landscape is crucial. Ecologists have begun paying attention to fragments of biodiversity habitats in the urban landscapes in the past few decades. Of these, academic campuses offer a unique opportunity to evaluate such fragments due to well-preserved green spaces within the campuses and maintenance of biodiversity data. We studied the scope of academic campuses in India for their biodiversity potential vis-à-vis their ability to retain the habitat for native biodiversity. We used bird richness as a surrogate to biodiversity as they are the most widely monitored species group. Academic campuses (n = 335) in India reported 779 bird species, with an average of 88 species per campus. The species included five critically endangered, seven endangered, 17 vulnerable, and 33 near-threatened species. Several campuses worldwide have held intact natural habitats for centuries. The campuses in India underwent human-induced habitat modification significantly less than their surrounding landscape in last one decade. The academic campuses globally could prove hugely beneficial in securing a wide variety of species in relatively small land areas. While our study was restricted to academic campuses, non-academic campuses such as the army, industrial and private establishments could further add to such spaces. The campuses could also serve as living repositories and evolutionary labs for plant and small animal species that remain isolated due to fragmentation.

Spatial genetic structure and limited gene flow in fragmented populations of the threatened Malleefowl (Leipoa ocellata)

The Malleefowl ( Leipoa ocellata ) is a threatened megapode bird that persists on the Eyre Peninsula of South Australia—an area that has undergone substantial clearance of native vegetation over the past 200 years. Habitat loss and fragmentation can negatively affect long-term conservation status by creating small and isolated subpopulations that lead to reduced gene flow, increased genetic drift, and inbreeding. In this study, we test whether Malleefowl on the Eyre Peninsula exhibit population structure that may have resulted from recent anthropogenic land cover changes. We used reduced-representation high-throughput DNA sequencing to obtain a dataset of 17,851 single nucleotide polymorphisms (SNPs). Our results suggest that Malleefowl are not genetically homogeneous across the Eyre Peninsula and that habitat fragmentation has likely driven differentiation of at least two distinct populations by decreasing opportunities for gene flow. We also provide preliminary genetic evidence for female-biased dispersal in Malleefowl. Our study highlights the potential problems caused by anthropogenic land cover changes for threatened Malleefowl populations and underscores the need for ongoing monitoring. We emphasise the importance of both large continuous native vegetation patches and small connecting habitat fragments even in highly fragmented landscapes. We encourage land managers to facilitate between-patch movement by improving native vegetation cover and controlling overabundant herbivores to improve habitat quality by allowing natural regrowth of existing native vegetation. • Habitat fragmentation has driven differentiation of Malleefowl populations on the Eyre Peninsula. • Preliminary genetic evidence for female-biased dispersal in a megapode. • Malleefowl management decisions should involve genetic targets. • Managers should facilitate between-patch gene flow by improving vegetation cover. • Lacking improvement, translocations may be necessary for better genetic health.

Mapping edaphic soils' conditions to identify conservation targets for pine barren and sandplain ecosystems in New York State.

Small habitat patches can be important reservoirs for biodiversity, capable of hosting unique species that are largely absent from the surrounding landscape. In cases where such patches owe their existence to the presence of particular soil types or hydrologic conditions, local‐scale edaphic variables may be more effective components for models that identify patch location than regional‐scale macroclimatic variables often used in habitat and species distribution models. We modeled the edaphic soil conditions that support pine barren, sandplain, and related ecosystems in New York State with the purpose of identifying potential locations for biodiversity conservation. We quantified soil percent sand and soil depth of 156 known high‐quality remnant pine barren and sandplain ecosystems to calculate threshold soil characteristics. We then mapped all soils in the state that were at least as sandy and deep as the threshold values we calculated. The total area of our map of suitable soil conditions was over 9500 km2, made up of forested (57%), urban (26%), agricultural (13%), and open (4%) land covers. Our analysis nearly doubled the recognized area of barren, shrubland, and grassland habitat on deep, sandy soils in New York State. Extensive forested and even agricultural cover on these soils could also be the subject of restoration to further support the biodiversity of these unique ecosystems. The presence of extensive soils in coastal and interior New York that, with the appropriate disturbance regime, have the potential to host pine barren and sandplain ecosystems offers a new perspective on these ecosystems' distribution in the past—and about how to better align conservation and restoration to preserve the future.

Abundance and Growth of the European Eels (Anguilla anguilla Linnaeus, 1758) in Small Estuarine Habitats from the Eastern English Channel

Abundance and growth of the European eel from six small northern French estuaries during their growth phase were examined to explore variations according to the local habitat characteristics. The length–weight relationships and growth models fitted to length-at-age back-calculated otolith growth increments were used to compare the growth. Higher abundances were observed in the smaller estuaries (2.4 to 10.5 ind. fyke nets 24 h−1). The eel length ranged from 215–924 mm with an age range of 4–21 years. There was no significant difference in fish eel lengths or age except in the Liane estuary where the individuals were larger. The length–weight relationships showed an isometric or positive allometric growth in most estuaries. The Gompertz growth models, which best fits the growth, showed no significant differences between estuaries except for female eels from the Liane and the Somme estuaries where the growth performance index was higher. The estimated annual growth rate varied from 2.7 to 115.0 mm·yr−1 for female and from 4.4 to 90.5 mm·yr−1 for male. The present study shows that eels in the six estuaries had CPUE and growth rates similar to those previously reported in larger habitats. These results reinforce the idea that small estuaries are important habitats that contribute significantly to the eel population and, therefore, play an essential role in conservation strategies for European eel.

Is there any suitable habitat left for the Critically Endangered Gurney’s Pitta’s in Thailand? Implications for species management

Summary Severe habitat loss has been widely suggested as the main cause for the near disappearance of Gurney’s Pitta across its range, with the species having been functionally extirpated from Thailand, and heavily reduced in Myanmar. Here we provide an overview of the decline in available habitat in the Thai portion of the range and the species prospects for reintroduction anywhere in Thailand. Little suitable habitat for the species has remained in the Thai part of its range since 1986, when the species was rediscovered and it has since declined to a level where viable populations cannot be found. Lowland forest (&lt;150 m asl) has been heavily fragmented with most remaining habitat found in patches smaller than 1 km2 and only 13 ranging between 1 and 5 km2. Under current conditions, viable populations of the species cannot be reintroduced into the wild. However, maintaining a free-ranging, captive population may be possible as several of the remaining small habitat patches are legally protected, although they would require substantial management.

Predicting the potential distribution of four endangered holoparasites and their primary hosts in China under climate change.

Climate change affects parasitic plants and their hosts on distributions. However, little is known about how parasites and their hosts shift in distribution, and niche overlap in response to global change remains unclear to date. Here, the potential distribution and habitat suitability of four endangered holoparasites and their primary hosts in northern China were predicted using MaxEnt based on occurrence records and bioclimatic variables. The results indicated that (1) Temperature annual range (Bio7) and Precipitation of driest quarter (Bio17) were identified as the common key climatic factors influencing distribution (percentage contribution > 10%) for Cynomorium songaricum vs. Nitraria sibirica (i.e., parasite vs. host); Temperature seasonality (Bio4) and Precipitation of driest month (Bio14) for Boschniakia rossica vs. Alnus mandshurica; Bio4 for Cistanche deserticola vs. Haloxylon ammodendron; Precipitation of warmest quarter (Bio18) for Cistanche mongolica vs. Tamarix ramosissima. Accordingly, different parasite-host pairs share to varying degree the common climatic factors. (2) Currently, these holoparasites had small suitable habitats (i.e., moderately and highly) (0.97–3.77%), with few highly suitable habitats (0.19–0.81%). Under future scenarios, their suitable habitats would change to some extent; their distribution shifts fell into two categories: growing type (Boschniakia rossica and Cistanche mongolica) and fluctuating type (Cynomorium songaricum and Cistanche deserticola). In contrast, the hosts’ current suitable habitats (1.42–13.43%) varied greatly, with highly restricted suitable habitats (0.18–1.00%). Under future scenarios, their suitable habitats presented different trends: growing type (Nitraria sibirica), declining type (Haloxylon ammodendron) and fluctuating type (the other hosts). (3) The niche overlaps between parasites and hosts differed significantly in the future, which can be grouped into two categories: growing type (Boschniakia rossica vs. Alnus mandshurica, Cistanche mongolica vs. Tamarix ramosissima), and fluctuating type (the others). Such niche overlap asynchronies may result in severe spatial limitations of parasites under future climate conditions. Our findings indicate that climate factors restricting parasites and hosts’ distributions, niche overlaps between them, together with parasitic species identity, may jointly influence the suitable habitats of parasitic plants. Therefore, it is necessary to take into account the threatened holoparasites themselves in conjunction with their suitable habitats and the parasite-host association when developing conservation planning in the future.

Population trends of resident and migrant West African bird species monitored over an 18-year period in central Nigeria

Almost no systematic monitoring of bird population trends occurs in West Africa, despite rapid human population increase, habitat change, and climate change, making conservation planning problematic. We monitored bird population trends using constant-effort mist netting, in a newly protected area (Amurum Forest Reserve) on the outskirts of Jos, central Nigeria, from 2002 to 2019. We modelled the 18-year changes in trends of 10 Palearctic migrant and 41 common resident bird species and related this to any changes in annual environmental site quality using NDVI and rainfall data. The populations of most bird species were stable; 30% of migrants and 7% of residents increased, while 10% of migrants and 29% of residents declined moderately. Primary productivity, measured by NDVI, increased, and rainfall pattern was stable, suggesting that environmental conditions at the site improved slightly during the period. However, only a few species showed significant correlations of population trends with NDVI and rainfall. Overall, our results suggest that population changes were locally similar for both the Afro-Palearctic and resident bird species, being reasonably stable or increasing — although perhaps this reflected the fact that the monitoring was done within a newly protected area, which at present represents the best habitat in the wider locality. Those species that declined were mostly associated with open, grassland areas, which will have decreased as anthropogenic influences were reduced at the study site. Though we only monitored one site, the results are encouraging in that simple protection of a small habitat fragment (∼300 ha) in Nigeria yielded generally positive population benefits for both resident and Palearctic migrant species.

Umbilicaria phaea var. coccinea: conservation status, variety rank, and secondary chemistry

Originally described from a single collection in northern California, Umbilicaria phaea var. coccinea has since been reported from additional sites in California, Oregon and Washington. Although relatively rare in all three states, there is currently no conservation status for U. phaea var. coccinea in California. Developing conservation strategies and status ranks requires a sound understanding of distribution, frequency, habitat requirements and taxonomic placement. Therefore, we evaluated distributions and constructed climate envelope models for both varieties of U. phaea. Umbilicaria phaea var. coccinea appears to be restricted to relatively small habitats within the range of U. phaea var. phaea and is only locally common in portions of the Klamath River watershed. To assess evolutionary relationships between the varieties, we evaluated four molecular loci: ITS2, LSU, Mcm7, and mtSSU. A combined phylogeny using maximum-likelihood and Bayesian inference indicated that U. phaea is monophyletic. Within the U. phaea clade, var. coccinea and var. phaea do not form mutually exclusive, monophyletic clades; instead, individuals are intermixed. Based on variation in pigment production, morphology, and geographic distribution, we recommend continued designation of U. phaea var. coccinea as a variety. To better understand the chemical diversity within U. phaea, we compared qualitative differences between secondary metabolite profiles of U. phaea var. phaea and U. phaea var. coccinea acetone extracts using ultraperformance-liquid chromatography high resolution tandem mass spectrometry in negative ion mode. UV spectroscopy, thin-layer chromatography and chemical spot testing were used to further characterize the compounds present. Overall, ten compounds were detected in extracts of U. phaea var. phaea and U. phaea var. coccinea. Five previously known chemical substances were identified in both U. phaea varieties including: orsellinic acid, lecanoric acid, hiascic acid, gyrophoric acid, and orsellinylgyrophorate, along with four unknown metabolites. One additional unknown substance whose chemical properties are consistent with a polyhydroxylated anthraquinone pigment was detected only in U. phaea var. coccinea. Given its rarity, chemical uniqueness, and distinct ecological association, U. phaea var. coccinea warrants a protected status throughout its range.