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Oak forests throughout North America are declining due to changes in disturbance regimes that have led to increased competition from other tree and shrub species. We evaluated associations between oak regeneration, the occurrence of two common invasive shrubs (common buckthorn (Rhamnus cathartica L.) and Tartarian honeysuckle (Lonicera tatarica L.)), and forest edges in oak forests in a portion of the midwestern United States where bur (Quercus macrocarpa Michx.), red (Quercus rubra L.), and white oak (Quercus alba L.) were historically dominant. We found poor recruitment of oaks in comparison to other, more shade-tolerant tree species. Results further revealed a strong stand-scale association between bur oak, open canopy conditions, high soil nutrient levels, and the presence of common buckthorn and Tartarian honeysuckle; these same site characteristics were disassociated with red and white oak. Within red and white oak stands, however, the presence of the invasive shrubs was more pronounced near forest edges. While oak recruitment is hampered throughout stands, our research suggests that predominant constraints may vary based on soil and light gradients found along forest edges. Les forets de chene deperissent, partout en Amerique du Nord, a cause de changements dans les regimes de perturbation qui ont entraine une augmentation de la competition d'autres especes d'arbre et d'arbuste. Nous avons evalue les liens entre la regeneration du chene, la presence de deux arbustes invasifs (le nerprun cathartique (Rhamnus cathartica L.) et le chevrefeuille de Tartari (Lonicera tatarica L.)) et la lisiere de la foret dans les forets de chene d'une partie du Midwest des Etats-Unis, ou les chenes a gros fruits (Quercus macrocarpa Michx.), rouge (Quercus rubra L.) et blanc (Quercus alba L.) etaient historiquement les especes dominantes. Nous avons trouve que le recrutement des chenes etait faible comparativement a d'autres especes d'arbre plus tolerantes a l'ombre. Les resultats revelent de plus qu'il y a une relation etroite a l'echelle du peuplement entre le chene a gros fruits, un couvert clairseme, une teneur elevee en nutriments dans le sol et la presence du nerprun cathartique et du chevrefeuille de Tartari; ces meme caracteristiques etaient negativement associees aux chenes rouge et blanc. Dans les peuplements de chenes rouge et blanc cependant, la presence des arbustes invasifs etait plus prononcee pres de la lisiere de la foret. Tandis que le recrutement du chene blanc est entrave dans l'ensemble des peuplements; nos travaux indiquent que les contraintes predominantes peuvent varier selon les gradients de sol et de lumiere le long de la lisiere de la foret. [Traduit par la Redaction], Introduction Oak forests across North America are undergoing dramatic changes as dominance shifts to more shade-tolerant later-successional species (Nowacki and Abrams 2008; Knoot et al. 2010a; McEwan et al. 2011), [...]

The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition, quality assessment and opportunity costs. Our knowledge about natural variation in male mate choosiness across different populations of the same species, however, remains limited. In this study, we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii (Gervais 1835), a species with overall high male mating investments, and evaluated the relative influence of population density and sex ratio (both affecting mate availability) on male mate choosiness. We investigated amplexus establishment after separating mating pairs and presenting focal males with a novel, size-matched female from the same population. Our analysis revealed considerable effects of sex ratio and (to a lesser extent) population density on time until amplexus establishment (choosiness). Male amphipods are able to perceive variable social conditions (e.g. sex ratio) and modify their mating strategy accordingly: We found choosiness to be reduced in increasingly male-biased populations, whereas selectivity increases when sex ratio becomes female biased. With this, our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio (i.e. level of competition) for male mating decisions in natural environments. Accounting for variation in sex ratios, therefore, allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies. [ABSTRACT FROM AUTHOR]

Dendrobatid poison frogs are known for their diverse parental care behaviours, including terrestrial egg attendance. While usually this behaviour is conducted by males, this study compared the pre-hatching investment of males and females in Ranitomeya imitator , a species with biparental care. Although males tended to spend more time with their eggs overall, there was no difference between sexes when comparing different types of care behaviour. Furthermore, both sexes increased general care behaviour when caring for more than one clutch. The finding that the sexes are relatively equal in their contribution to basic parental care forms provides a basis to understand why biparental care is stable in this species. [ABSTRACT FROM AUTHOR]

A dominant trend in arable farming systems worldwide is the replacement of large areas of perennial vegetation with a small number of annual crops (Green et al., 2005). Some of [...]

Using data from a sample of college students from several campuses throughout the United States, this research examines whether ethnic differences (African Americans versus European Americans) in attitudes toward gays and lesbians area function of religious attendance. Multiple regressions were run separately for attitudes towards lesbians and attitudes toward gay men. When predicting attitudes toward lesbians, ethnic differences were present in the absence of religious altitudes; however, when religious attitudes were entered into the model, ethnic differences disappeared. In predicting attitudes toward gay men, ethnic differences were never present, while religious attitudes were always statistically significant. We conclude that differences in altitudes toward homosexuals in general, and gay men specifically, are not necessarily a function of ethnicity but possibly of religious attendance and the effect of the 'Black church.' We end with a discussion of the link between ethnicity, religion, HIV/AIDS, and heterosexism in the African American community. [Article copies available for a fee from The Haworth Document Delivery Service: 1.800-HAWORTH. E-mail address: Website: KEYWORDS. Ethnicity, religion, attitudes, gays, lesbians, heterosexism, African American, European American, Black church

International agreements aim to conserve 17% of Earth's land area by 2020 but include no area‐based conservation targets within the working landscapes that support human needs through farming, ranching, and forestry. Through a review of country‐level legislation, we found that just 38% of countries have minimum area requirements for conserving native habitats within working landscapes. We argue for increasing native habitats to at least 20% of working landscape area where it is below this minimum. Such target has benefits for food security, nature's contributions to people, and the connectivity and effectiveness of protected area networks in biomes in which protected areas are underrepresented. We also argue for maintaining native habitat at higher levels where it currently exceeds the 20% minimum, and performed a literature review that shows that even more than 50% native habitat restoration is needed in particular landscapes. The post‐2020 Global Biodiversity Framework is an opportune moment to include a minimum habitat restoration target for working landscapes that contributes to, but does not compete with, initiatives for expanding protected areas, the UN Decade on Ecosystem Restoration (2021–2030) and the UN Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

Soybeans cover 129 million hectares globally. Soybean productivity can increase with pollinator management, but soybean cultivation practices commonly ignore biotic pollination. If pollinator habitats are created within soybean landscapes and policies to limit agricultural expansion are implemented, millions of hectares could be restored for biodiversity without loss of soybean production. [ABSTRACT FROM AUTHOR]