Source and Accumulation of Soil Carbon along Catena Toposequences over 12,000 Years in Three Semi-Natural Miscanthus sinensis Grasslands in Japan

Miscanthus-dominated semi-natural grasslands in Japan appear to store considerable amounts of soil C. To estimate the long-term effect of Miscanthus vegetation on the accumulation of soil carbon by soil biota degradation in its native range, we measured total soil C from the surface to a 1.2 m depth along a catena toposequence in three annually burned grasslands in Japan: Kawatabi, Soni, and Aso. Soil C stock was estimated using a radiocarbon age and depth model, resulting in a net soil C accumulation rate in the soil. C4-plant contribution to soil C accumulation was further estimated by δ13C of soil C. The range of total soil C varied among the sites (i.e., Kawatabi: 379–638 Mg, Soni: 249–484, and Aso: 372–408 Mg C ha−1). Catena position was a significant factor at Kawatabi and Soni, where the toe slope soil C accumulation exceeded that of the summit. The soil C accumulation rate of the whole horizon in the grasslands, derived C mainly from C4 plant species, was 0.05 ± 0.02 (Average ± SE), 0.04 ± 0.00, and 0.24 ± 0.04 Mg C ha−1 yr−1 in Kawatabi, Soni, and Aso, respectively. Potential exists for long-term sequestration of C under M. sinensis, but the difference in the C accumulation rate can be influenced by the catena position and the amount of vegetation.

Landscape Planning for Conservation: The Case of the Flora and Fauna Protection Area “Sierra de San Miguelito”, San Luis Potosi, Mexico

A supporting study was developed to identify the priority elements for conservation in the region called “Sierra de San Miguelito” (SSM), in the San Luis Potosi State (SLP), Mexico, with the purpose of establishing a federal protected natural area (PNA). The methodological approach used was the integral-spatial analysis applied in territorial planning processes. The study showed that the forests, xerophilous scrubland, and natural grasslands of the SSM present a high biodiversity, an abundance of endemism (27% of species are endemic to the country, n = 285), and protected species (5% of reported species). In addition, 32.74% of vertebrates and 18.32% of flora reported for SLP status is present in SSM, with an area that represents only 1.79% of the state territory. As a result of the study, an area of 109,638.95 ha was proposed to be declared a federally PNA. The area provides environmental services that favor the San Luis Potosí city (SLPc) and the surrounding population; therefore, its conservation will promote the preservation of natural, cultural, and landscape heritage, being a transversal axis for sustainable development in its area of influence. The result was the basis for starting the negotiation process, developed in 2021, for the creation of the PNA.

Fine-grain beta diversity in Palaearctic open vegetation: variability within and between biomes and vegetation types

Aims: To quantify how fine-grain (within-plot) beta diversity differs among biomes and vegetation types. Study area: Palaearctic biogeographic realm. Methods: We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database spanning broad geographic and ecological gradients. Next, we calculated the slope parameter (z-value) of the power-law species–area relationship (SAR) to use as a measure of multiplicative beta diversity. We did this separately for vascular plants, bryophytes and lichens and for the three groups combined (complete vegetation). We then tested whether z-values differed between biomes, ecological-physiognomic vegetation types at coarse and fine levels and phytosociological classes. Results: We found that z-values varied significantly among biomes and vegetation types. The explanatory power of area for species richness was highest for vascular plants, followed by complete vegetation, bryophytes and lichens. Within each species group, the explained variance increased with typological resolution. In vascular plants, adjusted R2 was 0.14 for biomes, but reached 0.50 for phytosociological classes. Among the biomes, mean z-values were particularly high in the Subtropics with winter rain (Mediterranean biome) and the Dry tropics and subtropics. Natural grasslands had higher z-values than secondary grasslands. Alpine and Mediterranean vegetation types had particularly high z-values whereas managed grasslands with benign soil and climate conditions and saline communities were characterised by particularly low z-values. Conclusions: In this study relating fine-grain beta diversity to typological units, we found distinct patterns. As we explain in a conceptual figure, these can be related to ultimate drivers, such as productivity, stress and disturbance, which can influence z-values via multiple pathways. The provided means, medians and quantiles of z-values for a wide range of typological entities provide benchmarks for local to continental studies, while calling for additional data from under-represented units. Syntaxonomic references: Mucina et al. (2016) for classes occurring in Europe; Ermakov (2012) for classes restricted to Asia. Abbreviations: ANOVA = analysis of variance; EDGG = Eurasian Dry Grassland Group; SAR = species-area relationship.

Fine-grain beta diversity in Palaearctic open vegetation: variability within and between biomes and vegetation types

Aims: To quantify how fine-grain (within-plot) beta diversity differs among biomes and vegetation types. Study area: Palaearctic biogeographic realm. Methods: We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database spanning broad geographic and ecological gradients. Next, we calculated the slope parameter (z-value) of the power-law species–area relationship (SAR) to use as a measure of multiplicative beta diversity. We did this separately for vascular plants, bryophytes and lichens and for the three groups combined (complete vegetation). We then tested whether z-values differed between biomes, ecological-physiognomic vegetation types at coarse and fine levels and phytosociological classes. Results: We found that z-values varied significantly among biomes and vegetation types. The explanatory power of area for species richness was highest for vascular plants, followed by complete vegetation, bryophytes and lichens. Within each species group, the explained variance increased with typological resolution. In vascular plants, adjusted R2 was 0.14 for biomes, but reached 0.50 for phytosociological classes. Among the biomes, mean z-values were particularly high in the Subtropics with winter rain (Mediterranean biome) and the Dry tropics and subtropics. Natural grasslands had higher z-values than secondary grasslands. Alpine and Mediterranean vegetation types had particularly high z-values whereas managed grasslands with benign soil and climate conditions and saline communities were characterised by particularly low z-values. Conclusions: In this study relating fine-grain beta diversity to typological units, we found distinct patterns. As we explain in a conceptual figure, these can be related to ultimate drivers, such as productivity, stress and disturbance, which can influence z-values via multiple pathways. The provided means, medians and quantiles of z-values for a wide range of typological entities provide benchmarks for local to continental studies, while calling for additional data from under-represented units. Syntaxonomic references: Mucina et al. (2016) for classes occurring in Europe; Ermakov (2012) for classes restricted to Asia. Abbreviations: ANOVA = analysis of variance; EDGG = Eurasian Dry Grassland Group; SAR = species-area relationship.

Small-scale drivers on plant and ant diversity in a grassland habitat through a multifaceted approach

Semi-natural grasslands are characterized by high biodiversity and require multifaceted approaches to monitor their biodiversity. Moreover, grasslands comprise a multitude of microhabitats, making the scale of investigation of fundamental importance. Despite their wide distribution, grasslands are highly threatened and are considered of high conservation priority by Directive no. 92/43/EEC. Here, we investigate the effects of small-scale ecological differences between two ecosites present within the EU habitat of Community Interest of semi-natural dry grasslands on calcareous substrates (6210 according to Dir. 92/43/EEC) occurring on a Mediterranean mountain. We measured taxonomic and functional diversity of plant and ant communities, evaluating the differences among the two ecosites, how these differences are influenced by the environment and whether vegetation affects composition of the ant community. Our results show that taxonomic and functional diversity of plant and ant communities are influenced by the environment. While vegetation has no effect on ant communities, we found plant and ant community composition differed across the two ecosites, filtering ant and plant species according to their functional traits, even at a small spatial scale. Our findings imply that small-scale monitoring is needed to effectively conserve priority habitats, especially for those that comprise multiple microhabitats.

INVASÃO POR GRAMÍNEAS EXÓTICAS EM CAMPOS SOBRE PALEODUNAS: EFEITOS NA DIVERSIDADE FLORÍSTICA

O Refúgio de Vida Silvestre Banhado dos Pachecos localiza-se sobre a Coxilha das Lombas, Viamão/RS, e encontra-se em processo de invasão biológica por gramíneas exóticas na área de campo seco. Este fragmento de vegetação campestre sobre paleodunas é habitat da espécie endêmica Ctenomys lami (Rodentia, Ctenomydae) e apresenta composição florística peculiar em relação a maioria das áreas naturais dos Campos Sulinos, com espécies de Asteraceae sendo dominantes em comparação às espécies de Poaceae. Com o objetivo de caracterizar a composição florística e avaliar o grau e efeitos da invasão biológica sobre a comunidade de campo seco foi realizado um levantamento quantitativo. Foram amostradas 31 parcelas de 1 x 1 m e levantados dados de cobertura e altura da vegetação, solo descoberto e serrapilheira. Foram calculados parâmetros fitossociológicos para cada espécie. As parcelas foram classificadas quanto ao nível de invasão por gramíneas exóticas. O efeito da invasão sobre a composição e estrutura da vegetação foi avaliado a partir de Análise de Coordenadas Principais, regressão linear e análise de variância. As gramíneas exóticas invasoras Urochloa decumbens e Digitaria eriantha subsp. pentzii foram dominantes em grande parte da vegetação campestre, modificando a estrutura e composição vegetal conforme o nível de invasão. Cerca de um terço da área encontra-se altamente invadida. Ações de remoção e controle de invasoras se fazem urgentes, considerando que este é um dos poucos fragmentos de ecossistemas naturais abertos na Coxilha das Lombas e abriga espécies ameaçadas de extinção. INVASION BY EXOTIC GRASSES IN GRASSLAND ON PALAEODUNES: EFFECTS ON FLORISTIC DIVERSITY. The Banhado dos Pachecos Wildlife Refuge, located in the Coxilha das Lombas, in Viamão/RS, Brazil, is under a process of invasion by alien grasses in its areas of dry grassland. The grassland on palaeo-dunes is the habitat of the endemic species Ctenomys lami (Rodentia, Ctenomydae) and presents a peculiar floristic composition in relation to most natural grasslands in southern Brazil, with species of the Asteraceae dominating in comparison to grasses. In order to characterize the floristic composition and to evaluate the degree and effects of biological invasion on the grassland community, a quantitative vegetation survey was carried out. In 31 plots of 1 x 1 m, data on cover and height of vegetation, bare soil and litter were collected. Phytosociological parameters were calculated for each species. The plots were classified according to the level of invasion by exotic grasses and Principal Coordinate Analysis, linear regression and Analysis of Variance were performed to observe the species distribution in the community and the effects of the invasion on the richness and structure of the vegetation. The invasive exotic grasses Urochloa decumbens and Digitaria eriantha subsp.pentzii were dominant in grassland vegetation, modifying plant structure and composition according to the level of invasion. About a third of the area is heavily invaded. Invasive removal and control actions are urgent as this is one of the few fragments of natural grasslands in the Coxilha das Lombas and is habitat to species threatened with extinction.

Dairy goat welfare in semi-intensive production systems and drought conditions

The region of Coquimbo has the highest percentage of goats (Capra hircus) in Chile and is severely affected by droughts. This can lead to environmental challenges such as limited water and forage availability when goats are kept in natural grasslands. The objective of this study was to assess the welfare of dairy goats in semi-intensive production systems under drought conditions. The study was carried out in La Serena city, region of Coquimbo, Chile and 22 semi-intensive dairy goat farms were assessed using the Animal Welfare Indicators protocol. In each evaluation, the following indicators and information were gathered: physical and behavioural indicators of animal welfare, farmers' sociodemographic information, farm facilities, husbandry practices and management of the farm, and farmers' perception of animal welfare. Of the goats evaluated (n = 446), the vast majority had a body condition score (BCS) considered normal (n = 349; 78.25%). The main welfare problems were poor hair condition, faecal soiling, overgrown claws and improper disbudding or dehorning. The majority of farmers (96%) considered it 'rather important' or 'very important' to handle their goats in a gentle manner, expressing concern about the welfare of their animals and considering pain as a negative experience for goats. A lower than expected percentage of very thin animals (low BCS) were seen, considering the drought conditions and the forage shortage that affects the region, and no animals were observed with signs of thermal stress. The semi-intensive production systems could be an alternative to pasture-based systems to overcome environmental challenges.

Endophytic fungi facilitate the coexistence of host grasses and neighboring legumes by changing rhizobial abundance

Purpose: Grass-endophyte and legume-rhizobium symbionts coexist in grasslands. However, the effects of endophyte infection on legume-rhizobium symbionts remain poorly understood, especially in natural grasslands. Methods: In this study, Achnatherum sibiricum - Epichloë endophytes and Medicago ruthenica -rhizobia were selected as materials to investigate whether and how endophyte infection affected the growth of legume-rhizobia symbionts. It was hypothesized that endophytes can facilitate the coexistence of grass-legume systems. Results: The results demonstrated that endophyte infection affected the growth of both rhizobia and M. ruthenica -rhizobia symbionts, and the results depended on rhizobial identity. Endophyte infection inhibited the growth of Mesorhizobium ciceri , which significantly promoted the growth of M. ruthenica , and promoted Sinorhizobium meliloti , which had no significant effect on the growth of M. ruthenica . Endophyte infection also changed the interaction between A. sibiricum and M. ruthenica . When inoculated with M. ciceri , endophyte infection weakened the promoting effect of A. sibiricum on M. ruthenica , while when inoculated with S. meliloti , endophyte infection enhanced the promoting effect. Endophyte infection affected the growth of M. ruthenica -rhizobia symbionts by affecting rhizobia abundance in roots and nitrogen content in plant leaves. Conclusion: In conclusion, endophyte infection was beneficial to biomass accumulation and species coexistence in grass-legume mixed planting systems. In this study, it was proposed that endophyte infection may change the growth of legume-rhizobia symbionts by affecting the growth and nitrogen fixation of rhizobia.

Comparison of Culturing and Metabarcoding Methods to Describe the Fungal Endophytic Assemblage of Brachypodium rupestre Growing in a Range of Anthropized Disturbance Regimes

Fungal endophytes develop inside plants without visible external signs, and they may confer adaptive advantages to their hosts. Culturing methods have been traditionally used to recognize the fungal endophytic assemblage, but novel metabarcoding techniques are being increasingly applied. This study aims to characterize the fungal endophytic assemblage in shoots, rhizomes and roots of the tall grass Brachypodium rupestre growing in a large area of natural grasslands with a continuum of anthropized disturbance regimes. Seven out of 88 taxa identified via metabarcoding accounted for 81.2% of the reads (Helotiaceae, Lachnum sp. A, Albotricha sp. A, Helotiales A, Agaricales A, Mycena sp. and Mollisiaceae C), revealing a small group of abundant endophytes and a large group of rare species. Although both methods detected the same trends in richness and fungal diversity among the tissues (root > rhizome > shoot) and grasslands (low-diversity > high-diversity grasslands), the metabarcoding tool identified 5.8 times more taxa than the traditional culturing method (15 taxa) but, surprisingly, failed to sequence the most isolated endophyte on plates, Omnidemptus graminis. Since both methods are still subject to important constraints, both are required to obtain a complete characterization of the fungal endophytic assemblage of the plant species.